Tag Archives: Core

Managing AWS Lambda Function Concurrency

Post Syndicated from Chris Munns original https://aws.amazon.com/blogs/compute/managing-aws-lambda-function-concurrency/

One of the key benefits of serverless applications is the ease in which they can scale to meet traffic demands or requests, with little to no need for capacity planning. In AWS Lambda, which is the core of the serverless platform at AWS, the unit of scale is a concurrent execution. This refers to the number of executions of your function code that are happening at any given time.

Thinking about concurrent executions as a unit of scale is a fairly unique concept. In this post, I dive deeper into this and talk about how you can make use of per function concurrency limits in Lambda.

Understanding concurrency in Lambda

Instead of diving right into the guts of how Lambda works, here’s an appetizing analogy: a magical pizza.
Yes, a magical pizza!

This magical pizza has some unique properties:

  • It has a fixed maximum number of slices, such as 8.
  • Slices automatically re-appear after they are consumed.
  • When you take a slice from the pizza, it does not re-appear until it has been completely consumed.
  • One person can take multiple slices at a time.
  • You can easily ask to have the number of slices increased, but they remain fixed at any point in time otherwise.

Now that the magical pizza’s properties are defined, here’s a hypothetical situation of some friends sharing this pizza.

Shawn, Kate, Daniela, Chuck, Ian and Avleen get together every Friday to share a pizza and catch up on their week. As there is just six of them, they can easily all enjoy a slice of pizza at a time. As they finish each slice, it re-appears in the pizza pan and they can take another slice again. Given the magical properties of their pizza, they can continue to eat all they want, but with two very important constraints:

  • If any of them take too many slices at once, the others may not get as much as they want.
  • If they take too many slices, they might also eat too much and get sick.

One particular week, some of the friends are hungrier than the rest, taking two slices at a time instead of just one. If more than two of them try to take two pieces at a time, this can cause contention for pizza slices. Some of them would wait hungry for the slices to re-appear. They could ask for a pizza with more slices, but then run the same risk again later if more hungry friends join than planned for.

What can they do?

If the friends agreed to accept a limit for the maximum number of slices they each eat concurrently, both of these issues are avoided. Some could have a maximum of 2 of the 8 slices, or other concurrency limits that were more or less. Just so long as they kept it at or under eight total slices to be eaten at one time. This would keep any from going hungry or eating too much. The six friends can happily enjoy their magical pizza without worry!

Concurrency in Lambda

Concurrency in Lambda actually works similarly to the magical pizza model. Each AWS Account has an overall AccountLimit value that is fixed at any point in time, but can be easily increased as needed, just like the count of slices in the pizza. As of May 2017, the default limit is 1000 “slices” of concurrency per AWS Region.

Also like the magical pizza, each concurrency “slice” can only be consumed individually one at a time. After consumption, it becomes available to be consumed again. Services invoking Lambda functions can consume multiple slices of concurrency at the same time, just like the group of friends can take multiple slices of the pizza.

Let’s take our example of the six friends and bring it back to AWS services that commonly invoke Lambda:

  • Amazon S3
  • Amazon Kinesis
  • Amazon DynamoDB
  • Amazon Cognito

In a single account with the default concurrency limit of 1000 concurrent executions, any of these four services could invoke enough functions to consume the entire limit or some part of it. Just like with the pizza example, there is the possibility for two issues to pop up:

  • One or more of these services could invoke enough functions to consume a majority of the available concurrency capacity. This could cause others to be starved for it, causing failed invocations.
  • A service could consume too much concurrent capacity and cause a downstream service or database to be overwhelmed, which could cause failed executions.

For Lambda functions that are launched in a VPC, you have the potential to consume the available IP addresses in a subnet or the maximum number of elastic network interfaces to which your account has access. For more information, see Configuring a Lambda Function to Access Resources in an Amazon VPC. For information about elastic network interface limits, see Network Interfaces section in the Amazon VPC Limits topic.

One way to solve both of these problems is applying a concurrency limit to the Lambda functions in an account.

Configuring per function concurrency limits

You can now set a concurrency limit on individual Lambda functions in an account. The concurrency limit that you set reserves a portion of your account level concurrency for a given function. All of your functions’ concurrent executions count against this account-level limit by default.

If you set a concurrency limit for a specific function, then that function’s concurrency limit allocation is deducted from the shared pool and assigned to that specific function. AWS also reserves 100 units of concurrency for all functions that don’t have a specified concurrency limit set. This helps to make sure that future functions have capacity to be consumed.

Going back to the example of the consuming services, you could set throttles for the functions as follows:

Amazon S3 function = 350
Amazon Kinesis function = 200
Amazon DynamoDB function = 200
Amazon Cognito function = 150
Total = 900

With the 100 reserved for all non-concurrency reserved functions, this totals the account limit of 1000.

Here’s how this works. To start, create a basic Lambda function that is invoked via Amazon API Gateway. This Lambda function returns a single “Hello World” statement with an added sleep time between 2 and 5 seconds. The sleep time simulates an API providing some sort of capability that can take a varied amount of time. The goal here is to show how an API that is underloaded can reach its concurrency limit, and what happens when it does.
To create the example function

  1. Open the Lambda console.
  2. Choose Create Function.
  3. For Author from scratch, enter the following values:
    1. For Name, enter a value (such as concurrencyBlog01).
    2. For Runtime, choose Python 3.6.
    3. For Role, choose Create new role from template and enter a name aligned with this function, such as concurrencyBlogRole.
  4. Choose Create function.
  5. The function is created with some basic example code. Replace that code with the following:

import time
from random import randint
seconds = randint(2, 5)

def lambda_handler(event, context):
time.sleep(seconds)
return {"statusCode": 200,
"body": ("Hello world, slept " + str(seconds) + " seconds"),
"headers":
{
"Access-Control-Allow-Headers": "Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token",
"Access-Control-Allow-Methods": "GET,OPTIONS",
}}

  1. Under Basic settings, set Timeout to 10 seconds. While this function should only ever take up to 5-6 seconds (with the 5-second max sleep), this gives you a little bit of room if it takes longer.

  1. Choose Save at the top right.

At this point, your function is configured for this example. Test it and confirm this in the console:

  1. Choose Test.
  2. Enter a name (it doesn’t matter for this example).
  3. Choose Create.
  4. In the console, choose Test again.
  5. You should see output similar to the following:

Now configure API Gateway so that you have an HTTPS endpoint to test against.

  1. In the Lambda console, choose Configuration.
  2. Under Triggers, choose API Gateway.
  3. Open the API Gateway icon now shown as attached to your Lambda function:

  1. Under Configure triggers, leave the default values for API Name and Deployment stage. For Security, choose Open.
  2. Choose Add, Save.

API Gateway is now configured to invoke Lambda at the Invoke URL shown under its configuration. You can take this URL and test it in any browser or command line, using tools such as “curl”:


$ curl https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01
Hello world, slept 2 seconds

Throwing load at the function

Now start throwing some load against your API Gateway + Lambda function combo. Right now, your function is only limited by the total amount of concurrency available in an account. For this example account, you might have 850 unreserved concurrency out of a full account limit of 1000 due to having configured a few concurrency limits already (also the 100 concurrency saved for all functions without configured limits). You can find all of this information on the main Dashboard page of the Lambda console:

For generating load in this example, use an open source tool called “hey” (https://github.com/rakyll/hey), which works similarly to ApacheBench (ab). You test from an Amazon EC2 instance running the default Amazon Linux AMI from the EC2 console. For more help with configuring an EC2 instance, follow the steps in the Launch Instance Wizard.

After the EC2 instance is running, SSH into the host and run the following:


sudo yum install go
go get -u github.com/rakyll/hey

“hey” is easy to use. For these tests, specify a total number of tests (5,000) and a concurrency of 50 against the API Gateway URL as follows(replace the URL here with your own):


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01

The output from “hey” tells you interesting bits of information:


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01

Summary:
Total: 381.9978 secs
Slowest: 9.4765 secs
Fastest: 0.0438 secs
Average: 3.2153 secs
Requests/sec: 13.0891
Total data: 140024 bytes
Size/request: 28 bytes

Response time histogram:
0.044 [1] |
0.987 [2] |
1.930 [0] |
2.874 [1803] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
3.817 [1518] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
4.760 [719] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
5.703 [917] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
6.647 [13] |
7.590 [14] |
8.533 [9] |
9.477 [4] |

Latency distribution:
10% in 2.0224 secs
25% in 2.0267 secs
50% in 3.0251 secs
75% in 4.0269 secs
90% in 5.0279 secs
95% in 5.0414 secs
99% in 5.1871 secs

Details (average, fastest, slowest):
DNS+dialup: 0.0003 secs, 0.0000 secs, 0.0332 secs
DNS-lookup: 0.0000 secs, 0.0000 secs, 0.0046 secs
req write: 0.0000 secs, 0.0000 secs, 0.0005 secs
resp wait: 3.2149 secs, 0.0438 secs, 9.4472 secs
resp read: 0.0000 secs, 0.0000 secs, 0.0004 secs

Status code distribution:
[200] 4997 responses
[502] 3 responses

You can see a helpful histogram and latency distribution. Remember that this Lambda function has a random sleep period in it and so isn’t entirely representational of a real-life workload. Those three 502s warrant digging deeper, but could be due to Lambda cold-start timing and the “second” variable being the maximum of 5, causing the Lambda functions to time out. AWS X-Ray and the Amazon CloudWatch logs generated by both API Gateway and Lambda could help you troubleshoot this.

Configuring a concurrency reservation

Now that you’ve established that you can generate this load against the function, I show you how to limit it and protect a backend resource from being overloaded by all of these requests.

  1. In the console, choose Configure.
  2. Under Concurrency, for Reserve concurrency, enter 25.

  1. Click on Save in the top right corner.

You could also set this with the AWS CLI using the Lambda put-function-concurrency command or see your current concurrency configuration via Lambda get-function. Here’s an example command:


$ aws lambda get-function --function-name concurrencyBlog01 --output json --query Concurrency
{
"ReservedConcurrentExecutions": 25
}

Either way, you’ve set the Concurrency Reservation to 25 for this function. This acts as both a limit and a reservation in terms of making sure that you can execute 25 concurrent functions at all times. Going above this results in the throttling of the Lambda function. Depending on the invoking service, throttling can result in a number of different outcomes, as shown in the documentation on Throttling Behavior. This change has also reduced your unreserved account concurrency for other functions by 25.

Rerun the same load generation as before and see what happens. Previously, you tested at 50 concurrency, which worked just fine. By limiting the Lambda functions to 25 concurrency, you should see rate limiting kick in. Run the same test again:


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01

While this test runs, refresh the Monitoring tab on your function detail page. You see the following warning message:

This is great! It means that your throttle is working as configured and you are now protecting your downstream resources from too much load from your Lambda function.

Here is the output from a new “hey” command:


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01
Summary:
Total: 379.9922 secs
Slowest: 7.1486 secs
Fastest: 0.0102 secs
Average: 1.1897 secs
Requests/sec: 13.1582
Total data: 164608 bytes
Size/request: 32 bytes

Response time histogram:
0.010 [1] |
0.724 [3075] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
1.438 [0] |
2.152 [811] |∎∎∎∎∎∎∎∎∎∎∎
2.866 [11] |
3.579 [566] |∎∎∎∎∎∎∎
4.293 [214] |∎∎∎
5.007 [1] |
5.721 [315] |∎∎∎∎
6.435 [4] |
7.149 [2] |

Latency distribution:
10% in 0.0130 secs
25% in 0.0147 secs
50% in 0.0205 secs
75% in 2.0344 secs
90% in 4.0229 secs
95% in 5.0248 secs
99% in 5.0629 secs

Details (average, fastest, slowest):
DNS+dialup: 0.0004 secs, 0.0000 secs, 0.0537 secs
DNS-lookup: 0.0002 secs, 0.0000 secs, 0.0184 secs
req write: 0.0000 secs, 0.0000 secs, 0.0016 secs
resp wait: 1.1892 secs, 0.0101 secs, 7.1038 secs
resp read: 0.0000 secs, 0.0000 secs, 0.0005 secs

Status code distribution:
[502] 3076 responses
[200] 1924 responses

This looks fairly different from the last load test run. A large percentage of these requests failed fast due to the concurrency throttle failing them (those with the 0.724 seconds line). The timing shown here in the histogram represents the entire time it took to get a response between the EC2 instance and API Gateway calling Lambda and being rejected. It’s also important to note that this example was configured with an edge-optimized endpoint in API Gateway. You see under Status code distribution that 3076 of the 5000 requests failed with a 502, showing that the backend service from API Gateway and Lambda failed the request.

Other uses

Managing function concurrency can be useful in a few other ways beyond just limiting the impact on downstream services and providing a reservation of concurrency capacity. Here are two other uses:

  • Emergency kill switch
  • Cost controls

Emergency kill switch

On occasion, due to issues with applications I’ve managed in the past, I’ve had a need to disable a certain function or capability of an application. By setting the concurrency reservation and limit of a Lambda function to zero, you can do just that.

With the reservation set to zero every invocation of a Lambda function results in being throttled. You could then work on the related parts of the infrastructure or application that aren’t working, and then reconfigure the concurrency limit to allow invocations again.

Cost controls

While I mentioned how you might want to use concurrency limits to control the downstream impact to services or databases that your Lambda function might call, another resource that you might be cautious about is money. Setting the concurrency throttle is another way to help control costs during development and testing of your application.

You might want to prevent against a function performing a recursive action too quickly or a development workload generating too high of a concurrency. You might also want to protect development resources connected to this function from generating too much cost, such as APIs that your Lambda function calls.

Conclusion

Concurrent executions as a unit of scale are a fairly unique characteristic about Lambda functions. Placing limits on how many concurrency “slices” that your function can consume can prevent a single function from consuming all of the available concurrency in an account. Limits can also prevent a function from overwhelming a backend resource that isn’t as scalable.

Unlike monolithic applications or even microservices where there are mixed capabilities in a single service, Lambda functions encourage a sort of “nano-service” of small business logic directly related to the integration model connected to the function. I hope you’ve enjoyed this post and configure your concurrency limits today!

The Raspberry Pi Christmas shopping list 2017

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/christmas-shopping-list-2017/

Looking for the perfect Christmas gift for a beloved maker in your life? Maybe you’d like to give a relative or friend a taste of the world of coding and Raspberry Pi? Whatever you’re looking for, the Raspberry Pi Christmas shopping list will point you in the right direction.

An ice-skating Raspberry Pi - The Raspberry Pi Christmas Shopping List 2017

For those getting started

Thinking about introducing someone special to the wonders of Raspberry Pi during the holidays? Although you can set up your Pi with peripherals from around your home, such as a mobile phone charger, your PC’s keyboard, and the old mouse dwelling in an office drawer, a starter kit is a nice all-in-one package for the budding coder.



Check out the starter kits from Raspberry Pi Approved Resellers such as Pimoroni, The Pi Hut, ModMyPi, Adafruit, CanaKit…the list is pretty long. Our products page will direct you to your closest reseller, or you can head to element14 to pick up the official Raspberry Pi Starter Kit.



You can also buy the Raspberry Pi Press’s brand-new Raspberry Pi Beginners Book, which includes a Raspberry Pi Zero W, a case, a ready-made SD card, and adapter cables.

Once you’ve presented a lucky person with their first Raspberry Pi, it’s time for them to spread their maker wings and learn some new skills.

MagPi Essentials books - The Raspberry Pi Christmas Shopping List 2017

To help them along, you could pick your favourite from among the Official Projects Book volume 3, The MagPi Essentials guides, and the brand-new third edition of Carrie Anne Philbin’s Adventures in Raspberry Pi. (She is super excited about this new edition!)

And you can always add a link to our free resources on the gift tag.

For the maker in your life

If you’re looking for something for a confident digital maker, you can’t go wrong with adding to their arsenal of electric and electronic bits and bobs that are no doubt cluttering drawers and boxes throughout their house.



Components such as servomotors, displays, and sensors are staples of the maker world. And when it comes to jumper wires, buttons, and LEDs, one can never have enough.



You could also consider getting your person a soldering iron, some helpings hands, or small tools such as a Dremel or screwdriver set.

And to make their life a little less messy, pop it all inside a Really Useful Box…because they’re really useful.



For kit makers

While some people like to dive into making head-first and to build whatever comes to mind, others enjoy working with kits.



The Naturebytes kit allows you to record the animal visitors of your garden with the help of a camera and a motion sensor. Footage of your local badgers, birds, deer, and more will be saved to an SD card, or tweeted or emailed to you if it’s in range of WiFi.

Cortec Tiny 4WD - The Raspberry Pi Christmas Shopping List 2017

Coretec’s Tiny 4WD is a kit for assembling a Pi Zero–powered remote-controlled robot at home. Not only is the robot adorable, building it also a great introduction to motors and wireless control.



Bare Conductive’s Touch Board Pro Kit offers everything you need to create interactive electronics projects using conductive paint.

Pi Hut Arcade Kit - The Raspberry Pi Christmas Shopping List 2017

Finally, why not help your favourite maker create their own gaming arcade using the Arcade Building Kit from The Pi Hut?

For the reader

For those who like to curl up with a good read, or spend too much of their day on public transport, a book or magazine subscription is the perfect treat.

For makers, hackers, and those interested in new technologies, our brand-new HackSpace magazine and the ever popular community magazine The MagPi are ideal. Both are available via a physical or digital subscription, and new subscribers to The MagPi also receive a free Raspberry Pi Zero W plus case.

Cover of CoderDojo Nano Make your own game

Marc Scott Beginner's Guide to Coding Book

You can also check out other publications from the Raspberry Pi family, including CoderDojo’s new CoderDojo Nano: Make Your Own Game, Eben Upton and Gareth Halfacree’s Raspberry Pi User Guide, and Marc Scott’s A Beginner’s Guide to Coding. And have I mentioned Carrie Anne’s Adventures in Raspberry Pi yet?

Stocking fillers for everyone

Looking for something small to keep your loved ones occupied on Christmas morning? Or do you have to buy a Secret Santa gift for the office tech? Here are some wonderful stocking fillers to fill your boots with this season.

Pi Hut 3D Christmas Tree - The Raspberry Pi Christmas Shopping List 2017

The Pi Hut 3D Xmas Tree: available as both a pre-soldered and a DIY version, this gadget will work with any 40-pin Raspberry Pi and allows you to create your own mini light show.



Google AIY Voice kit: build your own home assistant using a Raspberry Pi, the MagPi Essentials guide, and this brand-new kit. “Google, play Mariah Carey again…”



Pimoroni’s Raspberry Pi Zero W Project Kits offer everything you need, including the Pi, to make your own time-lapse cameras, music players, and more.



The official Raspberry Pi Sense HAT, Camera Module, and cases for the Pi 3 and Pi Zero will complete the collection of any Raspberry Pi owner, while also opening up exciting project opportunities.

STEAM gifts that everyone will love

Awesome Astronauts | Building LEGO’s Women of NASA!

LEGO Idea’s bought out this amazing ‘Women of NASA’ set, and I thought it would be fun to build, play and learn from these inspiring women! First up, let’s discover a little more about Sally Ride and Mae Jemison, two AWESOME ASTRONAUTS!

Treat the kids, and big kids, in your life to the newest LEGO Ideas set, the Women of NASA — starring Nancy Grace Roman, Margaret Hamilton, Sally Ride, and Mae Jemison!



Explore the world of wearables with Pimoroni’s sewable, hackable, wearable, adorable Bearables kits.



Add lights and motors to paper creations with the Activating Origami Kit, available from The Pi Hut.




We all loved Hidden Figures, and the STEAM enthusiast you know will do too. The film’s available on DVD, and you can also buy the original book, along with other fascinating non-fiction such as Rebecca Skloot’s The Immortal Life of Henrietta Lacks, Rachel Ignotofsky’s Women in Science, and Sydney Padua’s (mostly true) The Thrilling Adventures of Lovelace and Babbage.

Have we missed anything?

With so many amazing kits, HATs, and books available from members of the Raspberry Pi community, it’s hard to only pick a few. Have you found something splendid for the maker in your life? Maybe you’ve created your own kit that uses the Raspberry Pi? Share your favourites with us in the comments below or via our social media accounts.

The post The Raspberry Pi Christmas shopping list 2017 appeared first on Raspberry Pi.

Running Windows Containers on Amazon ECS

Post Syndicated from Nathan Taber original https://aws.amazon.com/blogs/compute/running-windows-containers-on-amazon-ecs/

This post was developed and written by Jeremy Cowan, Thomas Fuller, Samuel Karp, and Akram Chetibi.

Containers have revolutionized the way that developers build, package, deploy, and run applications. Initially, containers only supported code and tooling for Linux applications. With the release of Docker Engine for Windows Server 2016, Windows developers have started to realize the gains that their Linux counterparts have experienced for the last several years.

This week, we’re adding support for running production workloads in Windows containers using Amazon Elastic Container Service (Amazon ECS). Now, Amazon ECS provides an ECS-Optimized Windows Server Amazon Machine Image (AMI). This AMI is based on the EC2 Windows Server 2016 AMI, and includes Docker 17.06 Enterprise Edition and the ECS Agent 1.16. This AMI provides improved instance and container launch time performance. It’s based on Windows Server 2016 Datacenter and includes Docker 17.06.2-ee-5, along with a new version of the ECS agent that now runs as a native Windows service.

In this post, I discuss the benefits of this new support, and walk you through getting started running Windows containers with Amazon ECS.

When AWS released the Windows Server 2016 Base with Containers AMI, the ECS agent ran as a process that made it difficult to monitor and manage. As a service, the agent can be health-checked, managed, and restarted no differently than other Windows services. The AMI also includes pre-cached images for Windows Server Core 2016 and Windows Server Nano Server 2016. By caching the images in the AMI, launching new Windows containers is significantly faster. When Docker images include a layer that’s already cached on the instance, Docker re-uses that layer instead of pulling it from the Docker registry.

The ECS agent and an accompanying ECS PowerShell module used to install, configure, and run the agent come pre-installed on the AMI. This guarantees there is a specific platform version available on the container instance at launch. Because the software is included, you don’t have to download it from the internet. This saves startup time.

The Windows-compatible ECS-optimized AMI also reports CPU and memory utilization and reservation metrics to Amazon CloudWatch. Using the CloudWatch integration with ECS, you can create alarms that trigger dynamic scaling events to automatically add or remove capacity to your EC2 instances and ECS tasks.

Getting started

To help you get started running Windows containers on ECS, I’ve forked the ECS reference architecture, to build an ECS cluster comprised of Windows instances instead of Linux instances. You can pull the latest version of the reference architecture for Windows.

The reference architecture is a layered CloudFormation stack, in that it calls other stacks to create the environment. Within the stack, the ecs-windows-cluster.yaml file contains the instructions for bootstrapping the Windows instances and configuring the ECS cluster. To configure the instances outside of AWS CloudFormation (for example, through the CLI or the console), you can add the following commands to your instance’s user data:

Import-Module ECSTools
Initialize-ECSAgent

Or

Import-Module ECSTools
Initialize-ECSAgent –Cluster MyCluster -EnableIAMTaskRole

If you don’t specify a cluster name when you initialize the agent, the instance is joined to the default cluster.

Adding -EnableIAMTaskRole when initializing the agent adds support for IAM roles for tasks. Previously, enabling this setting meant running a complex script and setting an environment variable before you could assign roles to your ECS tasks.

When you enable IAM roles for tasks on Windows, it consumes port 80 on the host. If you have tasks that listen on port 80 on the host, I recommend configuring a service for them that uses load balancing. You can use port 80 on the load balancer, and the traffic can be routed to another host port on your container instances. For more information, see Service Load Balancing.

Create a cluster

To create a new ECS cluster, choose Launch stack, or pull the GitHub project to your local machine and run the following command:

aws cloudformation create-stack –template-body file://<path to master-windows.yaml> --stack-name <name>

Upload your container image

Now that you have a cluster running, step through how to build and push an image into a container repository. You use a repository hosted in Amazon Elastic Container Registry (Amazon ECR) for this, but you could also use Docker Hub. To build and push an image to a repository, install Docker on your Windows* workstation. You also create a repository and assign the necessary permissions to the account that pushes your image to Amazon ECR. For detailed instructions, see Pushing an Image.

* If you are building an image that is based on Windows layers, then you must use a Windows environment to build and push your image to the registry.

Write your task definition

Now that your image is built and ready, the next step is to run your Windows containers using a task.

Start by creating a new task definition based on the windows-simple-iis image from Docker Hub.

  1. Open the ECS console.
  2. Choose Task Definitions, Create new task definition.
  3. Scroll to the bottom of the page and choose Configure via JSON.
  4. Copy and paste the following JSON into that field.
  5. Choose Save, Create.
{
   "family": "windows-simple-iis",
   "containerDefinitions": [
   {
     "name": "windows_sample_app",
     "image": "microsoft/iis",
     "cpu": 100,
     "entryPoint":["powershell", "-Command"],
     "command":["New-Item -Path C:\\inetpub\\wwwroot\\index.html -Type file -Value '<html><head><title>Amazon ECS Sample App</title> <style>body {margin-top: 40px; background-color: #333;} </style> </head><body> <div style=color:white;text-align:center><h1>Amazon ECS Sample App</h1> <h2>Congratulations!</h2> <p>Your application is now running on a container in Amazon ECS.</p></body></html>'; C:\\ServiceMonitor.exe w3svc"],
     "portMappings": [
     {
       "protocol": "tcp",
       "containerPort": 80,
       "hostPort": 8080
     }
     ],
     "memory": 500,
     "essential": true
   }
   ]
}

You can now go back into the Task Definition page and see windows-simple-iis as an available task definition.

There are a few important aspects of the task definition file to note when working with Windows containers. First, the hostPort is configured as 8080, which is necessary because the ECS agent currently uses port 80 to enable IAM roles for tasks required for least-privilege security configurations.

There are also some fairly standard task parameters that are intentionally not included. For example, network mode is not available with Windows at the time of this release, so keep that setting blank to allow Docker to configure WinNAT, the only option available today.

Also, some parameters work differently with Windows than they do with Linux. The CPU limits that you define in the task definition are absolute, whereas on Linux they are weights. For information about other task parameters that are supported or possibly different with Windows, see the documentation.

Run your containers

At this point, you are ready to run containers. There are two options to run containers with ECS:

  1. Task
  2. Service

A task is typically a short-lived process that ECS creates. It can’t be configured to actively monitor or scale. A service is meant for longer-running containers and can be configured to use a load balancer, minimum/maximum capacity settings, and a number of other knobs and switches to help ensure that your code keeps running. In both cases, you are able to pick a placement strategy and a specific IAM role for your container.

  1. Select the task definition that you created above and choose Action, Run Task.
  2. Leave the settings on the next page to the default values.
  3. Select the ECS cluster created when you ran the CloudFormation template.
  4. Choose Run Task to start the process of scheduling a Docker container on your ECS cluster.

You can now go to the cluster and watch the status of your task. It may take 5–10 minutes for the task to go from PENDING to RUNNING, mostly because it takes time to download all of the layers necessary to run the microsoft/iis image. After the status is RUNNING, you should see the following results:

You may have noticed that the example task definition is named windows-simple-iis:2. This is because I created a second version of the task definition, which is one of the powerful capabilities of using ECS. You can make the task definitions part of your source code and then version them. You can also roll out new versions and practice blue/green deployment, switching to reduce downtime and improve the velocity of your deployments!

After the task has moved to RUNNING, you can see your website hosted in ECS. Find the public IP or DNS for your ECS host. Remember that you are hosting on port 8080. Make sure that the security group allows ingress from your client IP address to that port and that your VPC has an internet gateway associated with it. You should see a page that looks like the following:

This is a nice start to deploying a simple single instance task, but what if you had a Web API to be scaled out and in based on usage? This is where you could look at defining a service and collecting CloudWatch data to add and remove both instances of the task. You could also use CloudWatch alarms to add more ECS container instances and keep up with the demand. The former is built into the configuration of your service.

  1. Select the task definition and choose Create Service.
  2. Associate a load balancer.
  3. Set up Auto Scaling.

The following screenshot shows an example where you would add an additional task instance when the CPU Utilization CloudWatch metric is over 60% on average over three consecutive measurements. This may not be aggressive enough for your requirements; it’s meant to show you the option to scale tasks the same way you scale ECS instances with an Auto Scaling group. The difference is that these tasks start much faster because all of the base layers are already on the ECS host.

Do not confuse task dynamic scaling with ECS instance dynamic scaling. To add additional hosts, see Tutorial: Scaling Container Instances with CloudWatch Alarms.

Conclusion

This is just scratching the surface of the flexibility that you get from using containers and Amazon ECS. For more information, see the Amazon ECS Developer Guide and ECS Resources.

– Jeremy, Thomas, Samuel, Akram

Game night 1: Lisa, Lisa, MOOP

Post Syndicated from Eevee original https://eev.ee/blog/2017/12/05/game-night-1-lisa-lisa-moop/

For the last few weeks, glip (my partner) and I have spent a couple hours most nights playing indie games together. We started out intending to play a short list of games that had been recommended to glip, but this turns out to be a nice way to wind down, so we’ve been keeping it up and clicking on whatever looks interesting in the itch app.

Most of the games are small and made by one or two people, so they tend to be pretty tightly scoped and focus on a few particular kinds of details. I’ve found myself having brain thoughts about all that, so I thought I’d write some of them down.

I also know that some people (cough) tend not to play games they’ve never heard of, even if they want something new to play. If that’s you, feel free to play some of these, now that you’ve heard of them!

Also, I’m still figuring the format out here, so let me know if this is interesting or if you hope I never do it again!

First up:

  • Lisa: The Painful
  • Lisa: The Joyful
  • MOOP

These are impressions, not reviews. I try to avoid major/ending spoilers, but big plot points do tend to leave impressions.

Lisa: The Painful

long · classic rpg · dec 2014 · lin/mac/win · $10 on itch or steam · website

(cw: basically everything??)

Lisa: The Painful is true to its name. I hesitate to describe it as fun, exactly, but I’m glad we played it.

Everything about the game is dark. It’s a (somewhat loose) sequel to another game called Lisa, whose titular character ultimately commits suicide; her body hanging from a noose is the title screen for this game.

Ah, but don’t worry, it gets worse. This game takes place in a post-apocalyptic wasteland, where every female human — women, children, babies — is dead. You play as Brad (Lisa’s brother), who has discovered the lone exception: a baby girl he names Buddy and raises like a daughter. Now, Buddy has been kidnapped, and you have to go rescue her, presumably from being raped.

Ah, but don’t worry, it gets worse.


I’ve had a hard time putting my thoughts in order here, because so much of what stuck with me is the way the game entangles the plot with the mechanics.

I love that kind of thing, but it’s so hard to do well. I can’t really explain why, but I feel like most attempts to do it fall flat — they have a glimmer of an idea, but they don’t integrate it well enough, or they don’t run nearly as far as they could have. I often get the same feeling as, say, a hyped-up big moral choice that turns out to be picking “yes” or “no” from a menu. The idea is there, but the execution is so flimsy that it leaves no impact on me at all.

An obvious recent success here is Undertale, where the entire story is about violence and whether you choose to engage or avoid it (and whether you can do that). If you choose to eschew violence, not only does the game become more difficult, it arguably becomes a different game entirely. Granted, the contrast is lost if you (like me) tried to play as a pacifist from the very beginning. I do feel that you could go further with the idea than Undertale, but Undertale itself doesn’t feel incomplete.

Christ, I’m not even talking about the right game any more.

Okay, so: this game is a “classic” RPG, by which I mean, it was made with RPG Maker. (It’s kinda funny that RPG Maker was designed to emulate a very popular battle style, and now the only games that use that style are… made with RPG Maker.) The main loop, on the surface, is standard RPG fare: you walk around various places, talk to people, solve puzzles, recruit party members, and get into turn-based fights.

Now, Brad is addicted to a drug called Joy. He will regularly go into withdrawal, which manifests in the game as a status effect that cuts his stats (even his max HP!) dramatically.

It is really, really, incredibly inconvenient. And therein lies the genius here. The game could have simply told me that Brad is an addict, and I don’t think I would’ve cared too much. An addiction to a fantasy drug in a wasteland doesn’t mean anything to me, especially about this tiny sprite man I just met, so I would’ve filed this away as a sterile fact and forgotten about it. By making his addiction affect me, I’m now invested in it. I wish Brad weren’t addicted, even if only because it’s annoying. I found a party member once who turned out to have the same addiction, and I felt dread just from seeing the icon for the status effect. I’ve been looped into the events of this story through the medium I use to interact with it: the game.

It’s a really good use of games as a medium. Even before I’m invested in the characters, I’m invested in what’s happening to them, because it impacts the game!

Incidentally, you can get Joy as an item, which will temporarily cure your withdrawal… but you mostly find it by looting the corpses of grotesque mutant flesh horrors you encounter. I don’t think the game would have the player abruptly mutate out of nowhere, but I wasn’t about to find out, either. We never took any.


Virtually every staple of the RPG genre has been played with in some way to tie it into the theme/setting. I love it, and I think it works so well precisely because it plays with expectations of how RPGs usually work.

Most obviously, the game is a sidescroller, not top-down. You can’t jump freely, but you can hop onto one-tile-high boxes and climb ropes. You can also drop off off ledges… but your entire party will take fall damage, which gets rapidly more severe the further you fall.

This wouldn’t be too much of a problem, except that healing is hard to come by for most of the game. Several hub areas have campfires you can sleep next to to restore all your health and MP, but when you wake up, something will have happened to you. Maybe just a weird cutscene, or maybe one of your party members has decided to leave permanently.

Okay, so use healing items instead? Good luck; money is also hard to come by, and honestly so are shops, and many of the healing items are woefully underpowered.

Grind for money? Good luck there, too! While the game has plenty of battles, virtually every enemy is a unique overworld human who only appears once, and then is dead, because you killed him. Only a handful of places have unlimited random encounters, and grinding is not especially pleasant.

The “best” way to get a reliable heal is to savescum — save the game, sleep by the campfire, and reload if you don’t like what you wake up to.

In a similar vein, there’s a part of the game where you’re forced to play Russian Roulette. You choose a party member; he and an opponent will take turns shooting themselves in the head until someone finds a loaded chamber. If your party member loses, he is dead. And you have to keep playing until you win three times, so there’s no upper limit on how many people you might lose. I couldn’t find any way to influence who won, so I just had to savescum for a good half hour until I made it through with minimal losses.

It was maddening, but also a really good idea. Games don’t often incorporate the existence of saves into the gameplay, and when they do, they usually break the fourth wall and get all meta about it. Saves are never acknowledged in-universe here (aside from the existence of save points), but surely these parts of the game were designed knowing that the best way through them is by reloading. It’s rarely done, it can easily feel unfair, and it drove me up the wall — but it was certainly painful, as intended, and I kinda love that.

(Naturally, I’m told there’s a hard mode, where you can only use each save point once.)

The game also drives home the finality of death much better than most. It’s not hard to overlook the death of a redshirt, a character with a bit part who simply doesn’t appear any more. This game permanently kills your party members. Russian Roulette isn’t even the only way you can lose them! Multiple cutscenes force you to choose between losing a life or some other drastic consequence. (Even better, you can try to fight the person forcing this choice on you, and he will decimate you.) As the game progresses, you start to encounter enemies who can simply one-shot murder your party members.

It’s such a great angle. Just like with Brad’s withdrawal, you don’t want to avoid their deaths because it’d be emotional — there are dozens of party members you can recruit (though we only found a fraction of them), and most of them you only know a paragraph about — but because it would inconvenience you personally. Chances are, you have your strongest dudes in your party at any given time, so losing one of them sucks. And with few random encounters, you can’t just grind someone else up to an appropriate level; it feels like there’s a finite amount of XP in the game, and if someone high-level dies, you’ve lost all the XP that went into them.


The battles themselves are fairly straightforward. You can attack normally or use a special move that costs MP. SP? Some kind of points.

Two things in particular stand out. One I mentioned above: the vast majority of the encounters are one-time affairs against distinct named NPCs, who you then never see again, because they are dead, because you killed them.

The other is the somewhat unusual set of status effects. The staples like poison and sleep are here, but don’t show up all that often; more frequent are statuses like weird, drunk, stink, or cool. If you do take Joy (which also cures depression), you become joyed for a short time.

The game plays with these in a few neat ways, besides just Brad’s withdrawal. Some party members have a status like stink or cool permanently. Some battles are against people who don’t want to fight at all — and so they’ll spend most of the battle crying, purely for flavor impact. Seeing that for the first time hit me pretty hard; until then we’d only seen crying as a mechanical side effect of having sand kicked in one’s face.


The game does drag on a bit. I think we poured 10 in-game hours into it, which doesn’t count time spent reloading. It doesn’t help that you walk not super fast.

My biggest problem was with getting my bearings; I’m sure we spent a lot of that time wandering around accomplishing nothing. Most of the world is focused around one of a few hub areas, and once you’ve completed one hub, you can move onto the next one. That’s fine. Trouble is, you can go any of a dozen different directions from each hub, and most of those directions will lead you to very similar-looking hills built out of the same tiny handful of tiles. The connections between places are mostly cave entrances, which also largely look the same. Combine that with needing to backtrack for puzzle or progression reasons, and it’s incredibly difficult to keep track of where you’ve been, what you’ve done, and where you need to go next.

I don’t know that the game is wrong here; the aesthetic and world layout are fantastic at conveying a desolate wasteland. I wouldn’t even be surprised if the navigation were deliberately designed this way. (On the other hand, assuming every annoyance in a despair-ridden game is deliberate might be giving it too much credit.) But damn it’s still frustrating.

I felt a little lost in the battle system, too. Towards the end of the game, Brad in particular had over a dozen skills he could use, but I still couldn’t confidently tell you which were the strongest. New skills sometimes appear in the middle of the list or cost less than previous skills, and the game doesn’t outright tell you how much damage any of them do. I know this is the “classic RPG” style, and I don’t think it was hugely inconvenient, but it feels weird to barely know how my own skills work. I think this puts me off getting into new RPGs, just generally; there’s a whole new set of things I have to learn about, and games in this style often won’t just tell me anything, so there’s this whole separate meta-puzzle to figure out before I can play the actual game effectively.

Also, the sound could use a little bit of… mastering? Some music and sound effects are significantly louder and screechier than others. Painful, you could say.


The world is full of side characters with their own stuff going on, which is also something I love seeing in games; too often, the whole world feels like an obstacle course specifically designed for you.

Also, many of those characters are, well, not great people. Really, most of the game is kinda fucked up. Consider: the weird status effect is most commonly inflicted by the “Grope” skill. It makes you feel weird, you see. Oh, and the currency is porn magazines.

And then there are the gangs, the various spins on sex clubs, the forceful drug kingpins, and the overall violence that permeates everything (you stumble upon an alarming number of corpses). The game neither condones nor condemns any of this; it simply offers some ideas of how people might behave at the end of the world. It’s certainly the grittiest interpretation I’ve seen.

I don’t usually like post-apocalypses, because they try to have these very hopeful stories, but then at the end the world is still a blighted hellscape so what was the point of any of that? I like this game much better for being a blighted hellscape throughout. The story is worth following to see where it goes, not just because you expect everything wrapped up neatly at the end.

…I realize I’ve made this game sound monumentally depressing throughout, but it manages to pack in a lot of funny moments as well, from the subtle to the overt. In retrospect, it’s actually really good at balancing the mood so it doesn’t get too depressing. If nothing else, it’s hilarious to watch this gruff, solemn, battle-scarred, middle-aged man pedal around on a kid’s bike he found.


An obvious theme of the game is despair, but the more I think about it, the more I wonder if ambiguity is a theme as well. It certainly fits the confusing geography.

Even the premise is a little ambiguous. Is/was Olathe a city, a country, a whole planet? Did the apocalypse affect only Olathe, or the whole world? Does it matter in an RPG, where the only world that exists is the one mapped out within the game?

Towards the end of the game, you catch up with Buddy, but she rejects you, apparently resentful that you kept her hidden away for her entire life. Brad presses on anyway, insisting on protecting her.

At that point I wasn’t sure I was still on Brad’s side. But he’s not wrong, either. Is he? Maybe it depends on how old Buddy is — but the game never tells us. Her sprite is a bit smaller than the men’s, but it’s hard to gauge much from small exaggerated sprites, and she might just be shorter. In the beginning of the game, she was doing kid-like drawings, but we don’t know how much time passed after that. Everyone seems to take for granted that she’s capable of bearing children, and she talks like an adult. So is she old enough to be making this decision, or young enough for parent figure Brad to overrule her? What is the appropriate age of agency, anyway, when you’re the last girl/woman left more than a decade after the end of the world?

Can you repopulate a species with only one woman, anyway?


Well, that went on a bit longer than I intended. This game has a lot of small touches that stood out to me, and they all wove together very well.

Should you play it? I have absolutely no idea.

FINAL SCORE: 1 out of 6 chambers

Lisa: The Joyful

fairly short · classic rpg · aug 2015 · lin/mac/win · $5 on itch or steam

Surprise! There’s a third game to round out this trilogy.

Lisa: The Joyful is much shorter, maybe three hours long — enough to be played in a night rather than over the better part of a week.

This one picks up immediately after the end of Painful, with you now playing as Buddy. It takes a drastic turn early on: Buddy decides that, rather than hide from the world, she must conquer it. She sets out to murder all the big bosses and become queen.

The battle system has been inherited from the previous game, but battles are much more straightforward this time around. You can’t recruit any party members; for much of the game, it’s just you and a sword.

There is a catch! Of course.

The catch is that you do not have enough health to survive most boss battles without healing. With no party members, you cannot heal via skills. I don’t think you could buy healing items anywhere, either. You have a few when the game begins, but once you run out, that’s it.

Except… you also have… some Joy. Which restores you to full health and also makes you crit with every hit. And drops off of several enemies.

We didn’t even recognize Joy as a healing item at first, since we never used it in Painful; it’s description simply says that it makes you feel nothing, and we’d assumed the whole point of it was to stave off withdrawal, which Buddy doesn’t experience. Luckily, the game provided a hint in the form of an NPC who offers to switch on easy mode:

What’s that? Bad guys too tough? Not enough jerky? You don’t want to take Joy!? Say no more, you’ve come to the right place!

So the game is aware that it’s unfairly difficult, and it’s deliberately forcing you to take Joy, and it is in fact entirely constructed around this concept. I guess the title is a pretty good hint, too.

I don’t feel quite as strongly about Joyful as I do about Painful. (Admittedly, I was really tired and starting to doze off towards the end of Joyful.) Once you get that the gimmick is to force you to use Joy, the game basically reduces to a moderate-difficulty boss rush. Other than that, the only thing that stood out to me mechanically was that Buddy learns a skill where she lifts her shirt to inflict flustered as a status effect — kind of a lingering echo of how outrageous the previous game could be.

You do get a healthy serving of plot, which is nice and ties a few things together. I wouldn’t say it exactly wraps up the story, but it doesn’t feel like it’s missing anything either; it’s exactly as murky as you’d expect.

I think it’s worth playing Joyful if you’ve played Painful. It just didn’t have the same impact on me. It probably doesn’t help that I don’t like Buddy as a person. She seems cold, violent, and cruel. Appropriate for the world and a product of her environment, I suppose.

FINAL SCORE: 300 Mags

MOOP

fairly short · inventory game · nov 2017 · win · free on itch

Finally, as something of a palate cleanser, we have MOOP: a delightful and charming little inventory game.

I don’t think “inventory game” is a real genre, but I mean the kind of game where you go around collecting items and using them in the right place. Puzzle-driven, but with “puzzles” that can largely be solved by simply trying everything everywhere. I’d put a lot of point and click adventures in the same category, despite having a radically different interface. Is that fair? Yes, because it’s my blog.

MOOP was almost certainly also made in RPG Maker, but it breaks the mold in a very different way by not being an RPG. There are no battles whatsoever, only interactions on the overworld; you progress solely via dialogue and puzzle-solving. Examining something gives you a short menu of verbs — use, talk, get — reminiscent of interactive fiction, or perhaps the graphical “adventure” games that took inspiration from interactive fiction. (God, “adventure game” is the worst phrase. Every game is an adventure! It doesn’t mean anything!)

Everything about the game is extremely chill. I love the monochrome aesthetic combined with a large screen resolution; it feels like I’m peeking into an alternate universe where the Game Boy got bigger but never gained color. I played halfway through the game before realizing that the protagonist (Moop) doesn’t have a walk animation; they simply slide around. Somehow, it works.

The puzzles are a little clever, yet low-pressure; the world is small enough that you can examine everything again if you get stuck, and there’s no way to lose or be set back. The music is lovely, too. It just feels good to wander around in a world that manages to make sepia look very pretty.

The story manages to pack a lot into a very short time. It’s… gosh, I don’t know. It has a very distinct texture to it that I’m not sure I’ve seen before. The plot weaves through several major events that each have very different moods, and it moves very quickly — but it’s well-written and doesn’t feel rushed or disjoint. It’s lighthearted, but takes itself seriously enough for me to get invested. It’s fucking witchcraft.

I think there was even a non-binary character! Just kinda nonchalantly in there. Awesome.

What a happy, charming game. Play if you would like to be happy and charmed.

FINAL SCORE: 1 waxing moon

Glenn’s Take on re:Invent Part 2

Post Syndicated from Glenn Gore original https://aws.amazon.com/blogs/architecture/glenns-take-on-reinvent-part-2/

Glenn Gore here, Chief Architect for AWS. I’m in Las Vegas this week — with 43K others — for re:Invent 2017. We’ve got a lot of exciting announcements this week. I’m going to check in to the Architecture blog with my take on what’s interesting about some of the announcements from an cloud architectural perspective. My first post can be found here.

The Media and Entertainment industry has been a rapid adopter of AWS due to the scale, reliability, and low costs of our services. This has enabled customers to create new, online, digital experiences for their viewers ranging from broadcast to streaming to Over-the-Top (OTT) services that can be a combination of live, scheduled, or ad-hoc viewing, while supporting devices ranging from high-def TVs to mobile devices. Creating an end-to-end video service requires many different components often sourced from different vendors with different licensing models, which creates a complex architecture and a complex environment to support operationally.

AWS Media Services
Based on customer feedback, we have developed AWS Media Services to help simplify distribution of video content. AWS Media Services is comprised of five individual services that can either be used together to provide an end-to-end service or individually to work within existing deployments: AWS Elemental MediaConvert, AWS Elemental MediaLive, AWS Elemental MediaPackage, AWS Elemental MediaStore and AWS Elemental MediaTailor. These services can help you with everything from storing content safely and durably to setting up a live-streaming event in minutes without having to be concerned about the underlying infrastructure and scalability of the stream itself.

In my role, I participate in many AWS and industry events and often work with the production and event teams that put these shows together. With all the logistical tasks they have to deal with, the biggest question is often: “Will the live stream work?” Compounding this fear is the reality that, as users, we are also quick to jump on social media and make noise when a live stream drops while we are following along remotely. Worse is when I see event organizers actively selecting not to live stream content because of the risk of failure and and exposure — leading them to decide to take the safe option and not stream at all.

With AWS Media Services addressing many of the issues around putting together a high-quality media service, live streaming, and providing access to a library of content through a variety of mechanisms, I can’t wait to see more event teams use live streaming without the concern and worry I’ve seen in the past. I am excited for what this also means for non-media companies, as video becomes an increasingly common way of sharing information and adding a more personalized touch to internally- and externally-facing content.

AWS Media Services will allow you to focus more on the content and not worry about the platform. Awesome!

Amazon Neptune
As a civilization, we have been developing new ways to record and store information and model the relationships between sets of information for more than a thousand years. Government census data, tax records, births, deaths, and marriages were all recorded on medium ranging from knotted cords in the Inca civilization, clay tablets in ancient Babylon, to written texts in Western Europe during the late Middle Ages.

One of the first challenges of computing was figuring out how to store and work with vast amounts of information in a programmatic way, especially as the volume of information was increasing at a faster rate than ever before. We have seen different generations of how to organize this information in some form of database, ranging from flat files to the Information Management System (IMS) used in the 1960s for the Apollo space program, to the rise of the relational database management system (RDBMS) in the 1970s. These innovations drove a lot of subsequent innovations in information management and application development as we were able to move from thousands of records to millions and billions.

Today, as architects and developers, we have a vast variety of database technologies to select from, which have different characteristics that are optimized for different use cases:

  • Relational databases are well understood after decades of use in the majority of companies who required a database to store information. Amazon Relational Database (Amazon RDS) supports many popular relational database engines such as MySQL, Microsoft SQL Server, PostgreSQL, MariaDB, and Oracle. We have even brought the traditional RDBMS into the cloud world through Amazon Aurora, which provides MySQL and PostgreSQL support with the performance and reliability of commercial-grade databases at 1/10th the cost.
  • Non-relational databases (NoSQL) provided a simpler method of storing and retrieving information that was often faster and more scalable than traditional RDBMS technology. The concept of non-relational databases has existed since the 1960s but really took off in the early 2000s with the rise of web-based applications that required performance and scalability that relational databases struggled with at the time. AWS published this Dynamo whitepaper in 2007, with DynamoDB launching as a service in 2012. DynamoDB has quickly become one of the critical design elements for many of our customers who are building highly-scalable applications on AWS. We continue to innovate with DynamoDB, and this week launched global tables and on-demand backup at re:Invent 2017. DynamoDB excels in a variety of use cases, such as tracking of session information for popular websites, shopping cart information on e-commerce sites, and keeping track of gamers’ high scores in mobile gaming applications, for example.
  • Graph databases focus on the relationship between data items in the store. With a graph database, we work with nodes, edges, and properties to represent data, relationships, and information. Graph databases are designed to make it easy and fast to traverse and retrieve complex hierarchical data models. Graph databases share some concepts from the NoSQL family of databases such as key-value pairs (properties) and the use of a non-SQL query language such as Gremlin. Graph databases are commonly used for social networking, recommendation engines, fraud detection, and knowledge graphs. We released Amazon Neptune to help simplify the provisioning and management of graph databases as we believe that graph databases are going to enable the next generation of smart applications.

A common use case I am hearing every week as I talk to customers is how to incorporate chatbots within their organizations. Amazon Lex and Amazon Polly have made it easy for customers to experiment and build chatbots for a wide range of scenarios, but one of the missing pieces of the puzzle was how to model decision trees and and knowledge graphs so the chatbot could guide the conversation in an intelligent manner.

Graph databases are ideal for this particular use case, and having Amazon Neptune simplifies the deployment of a graph database while providing high performance, scalability, availability, and durability as a managed service. Security of your graph database is critical. To help ensure this, you can store your encrypted data by running AWS in Amazon Neptune within your Amazon Virtual Private Cloud (Amazon VPC) and using encryption at rest integrated with AWS Key Management Service (AWS KMS). Neptune also supports Amazon VPC and AWS Identity and Access Management (AWS IAM) to help further protect and restrict access.

Our customers now have the choice of many different database technologies to ensure that they can optimize each application and service for their specific needs. Just as DynamoDB has unlocked and enabled many new workloads that weren’t possible in relational databases, I can’t wait to see what new innovations and capabilities are enabled from graph databases as they become easier to use through Amazon Neptune.

Look for more on DynamoDB and Amazon S3 from me on Monday.

 

Glenn at Tour de Mont Blanc

 

 

AWS Cloud9 – Cloud Developer Environments

Post Syndicated from Randall Hunt original https://aws.amazon.com/blogs/aws/aws-cloud9-cloud-developer-environments/

One of the first things you learn when you start programming is that, just like any craftsperson, your tools matter. Notepad.exe isn’t going to cut it. A powerful editor and testing pipeline supercharge your productivity. I still remember learning to use Vim for the first time and being able to zip around systems and complex programs. Do you remember how hard it was to setup all your compilers and dependencies on a new machine? How many cycles have you wasted matching versions, tinkering with configs, and then writing documentation to onboard a new developer to a project?

Today we’re launching AWS Cloud9, an Integrated Development Environment (IDE) for writing, running, and debugging code, all from your web browser. Cloud9 comes prepackaged with essential tools for many popular programming languages (Javascript, Python, PHP, etc.) so you don’t have to tinker with installing various compilers and toolchains. Cloud9 also provides a seamless experience for working with serverless applications allowing you to quickly switch between local and remote testing or debugging. Based on the popular open source Ace Editor and c9.io IDE (which we acquired last year), AWS Cloud9 is designed to make collaborative cloud development easy with extremely powerful pair programming features. There are more features than I could ever cover in this post but to give a quick breakdown I’ll break the IDE into 3 components: The editor, the AWS integrations, and the collaboration.

Editing


The Ace Editor at the core of Cloud9 is what lets you write code quickly, easily, and beautifully. It follows a UNIX philosophy of doing one thing and doing it well: writing code.

It has all the typical IDE features you would expect: live syntax checking, auto-indent, auto-completion, code folding, split panes, version control integration, multiple cursors and selections, and it also has a few unique features I want to highlight. First of all, it’s fast, even for large (100000+ line) files. There’s no lag or other issues while typing. It has over two dozen themes built-in (solarized!) and you can bring all of your favorite themes from Sublime Text or TextMate as well. It has built-in support for 40+ language modes and customizable run configurations for your projects. Most importantly though, it has Vim mode (or emacs if your fingers work that way). It also has a keybinding editor that allows you to bend the editor to your will.

The editor supports powerful keyboard navigation and commands (similar to Sublime Text or vim plugins like ctrlp). On a Mac, with ⌘+P you can open any file in your environment with fuzzy search. With ⌘+. you can open up the command pane which allows you to do invoke any of the editor commands by typing the name. It also helpfully displays the keybindings for a command in the pane, for instance to open to a terminal you can press ⌥+T. Oh, did I mention there’s a terminal? It ships with the AWS CLI preconfigured for access to your resources.

The environment also comes with pre-installed debugging tools for many popular languages – but you’re not limited to what’s already installed. It’s easy to add in new programs and define new run configurations.

The editor is just one, admittedly important, component in an IDE though. I want to show you some other compelling features.

AWS Integrations

The AWS Cloud9 IDE is the first IDE I’ve used that is truly “cloud native”. The service is provided at no additional charge, and you only charged for the underlying compute and storage resources. When you create an environment you’re prompted for either: an instance type and an auto-hibernate time, or SSH access to a machine of your choice.

If you’re running in AWS the auto-hibernate feature will stop your instance shortly after you stop using your IDE. This can be a huge cost savings over running a more permanent developer desktop. You can also launch it within a VPC to give it secure access to your development resources. If you want to run Cloud9 outside of AWS, or on an existing instance, you can provide SSH access to the service which it will use to create an environment on the external machine. Your environment is provisioned with automatic and secure access to your AWS account so you don’t have to worry about copying credentials around. Let me say that again: you can run this anywhere.

Serverless Development with AWS Cloud9

I spend a lot of time on Twitch developing serverless applications. I have hundreds of lambda functions and APIs deployed. Cloud9 makes working with every single one of these functions delightful. Let me show you how it works.


If you look in the top right side of the editor you’ll see an AWS Resources tab. Opening this you can see all of the lambda functions in your region (you can see functions in other regions by adjusting your region preferences in the AWS preference pane).

You can import these remote functions to your local workspace just by double-clicking them. This allows you to edit, test, and debug your serverless applications all locally. You can create new applications and functions easily as well. If you click the Lambda icon in the top right of the pane you’ll be prompted to create a new lambda function and Cloud9 will automatically create a Serverless Application Model template for you as well. The IDE ships with support for the popular SAM local tool pre-installed. This is what I use in most of my local testing and serverless development. Since you have a terminal, it’s easy to install additional tools and use other serverless frameworks.

 

Launching an Environment from AWS CodeStar

With AWS CodeStar you can easily provision an end-to-end continuous delivery toolchain for development on AWS. Codestar provides a unified experience for building, testing, deploying, and managing applications using AWS CodeCommit, CodeBuild, CodePipeline, and CodeDeploy suite of services. Now, with a few simple clicks you can provision a Cloud9 environment to develop your application. Your environment will be pre-configured with the code for your CodeStar application already checked out and git credentials already configured.

You can easily share this environment with your coworkers which leads me to another extremely useful set of features.

Collaboration

One of the many things that sets AWS Cloud9 apart from other editors are the rich collaboration tools. You can invite an IAM user to your environment with a few clicks.

You can see what files they’re working on, where their cursors are, and even share a terminal. The chat features is useful as well.

Things to Know

  • There are no additional charges for this service beyond the underlying compute and storage.
  • c9.io continues to run for existing users. You can continue to use all the features of c9.io and add new team members if you have a team account. In the future, we will provide tools for easy migration of your c9.io workspaces to AWS Cloud9.
  • AWS Cloud9 is available in the US West (Oregon), US East (Ohio), US East (N.Virginia), EU (Ireland), and Asia Pacific (Singapore) regions.

I can’t wait to see what you build with AWS Cloud9!

Randall

Announcing FreeRTOS Kernel Version 10 (AWS Open Source Blog)

Post Syndicated from jake original https://lwn.net/Articles/740372/rss

Amazon has announced the release of FreeRTOS kernel version 10, with a new license: “FreeRTOS was created in 2003 by Richard Barry. It rapidly became popular, consistently ranking very high in EETimes surveys on embedded operating systems. After 15 years of maintaining this critical piece of software infrastructure with very limited human resources, last year Richard joined Amazon.

Today we are releasing the core open source code as FreeRTOS kernel version 10, now under the MIT license (instead of its previous modified GPLv2 license). Simplified licensing has long been requested by the FreeRTOS community. The specific choice of the MIT license was based on the needs of the embedded systems community: the MIT license is commonly used in open hardware projects, and is generally whitelisted for enterprise use.” While the modified GPLv2 was removed, it was replaced with a slightly modified MIT license that adds: “If you wish to use our Amazon FreeRTOS name, please do so in a
fair use way that does not cause confusion.
” There is concern that change makes it a different license; the Open Source Initiative and Amazon open-source folks are working on clarifying that.

T2 Unlimited – Going Beyond the Burst with High Performance

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/new-t2-unlimited-going-beyond-the-burst-with-high-performance/

I first wrote about the T2 instances in the summer of 2014, and talked about how many workloads have a modest demand for continuous compute power and an occasional need for a lot more. This model resonated with our customers; the T2 instances are very popular and are now used to host microservices, low-latency interactive applications, virtual desktops, build & staging environments, prototypes, and the like.

New T2 Unlimited
Today we are extending the burst model that we pioneered with the T2, giving you the ability to sustain high CPU performance over any desired time frame while still keeping your costs as low as possible. You simply enable this feature when you launch your instance; you can also enable it for an instance that is already running. The hourly T2 instance price covers all interim spikes in usage if the average CPU utilization is lower than the baseline over a 24-hour window. There’s a small hourly charge if the instance runs at higher CPU utilization for a prolonged period of time. For example, if you run a t2.micro instance at an average of 15% utilization (5% above the baseline) for 24 hours you will be charged an additional 6 cents (5 cents per vCPU-hour * 1 vCPU * 5% * 24 hours).

To launch a T2 Unlimited instance from the EC2 Console, select any T2 instance and then click on Enable next to T2 Unlimited:

And here’s how to switch a running instance from T2 Standard to T2 Unlimited:

Behind the Scenes
As I described in my original post, each T2 instance accumulates CPU Credits as it runs and consumes them while it is running at full-core speed, decelerating to a baseline level when the supply of Credits is exhausted. T2 Unlimited instances have the ability to borrow an entire day’s worth of future credits, allowing them to perform additional bursting. This borrowing is tracked by the new CPUSurplusCreditBalance CloudWatch metric. When this balance rises to the level where it represents an entire day’s worth of future credits, the instance continues to deliver full-core performance, charged at the rate of $0.05 per vCPU per hour for Linux and $0.096 for Windows. These charged surplus credits are tracked by the new CPUSurplusCreditsCharged metric. You will be charged on a per-millisecond basis for partial hours of bursting (further reducing your costs) if you exhaust your surplus late in a given hour.

The charge for any remaining CPUSurplusCreditBalance is processed when the instance is terminated or configured as a T2 Standard. Any accumulated CPUCreditBalance carries over during the transition to T2 Standard.

The T2 Unlimited model is designed to spare you the trouble of watching the CloudWatch metrics, but (if you are like me) you will do it anyway. Let’s take a quick look at a t2.nano and watch the credits over time. First, CPU utilization grows to 100% and the instance begins to consume 5 credits every 5 minutes (one credit is equivalent to a VCPU-minute):

The CPU credit balance remains at 0 because the credits are being produced and consumed at the same rate. The surplus credit balance (tracked by the CPUSurplusCreditBalance metric) ramps up to 72, representing the credits that are being borrowed from the future:

Once the surplus credit balance hits 72, there’s nothing more to borrow from the future, and any further CPU usage is charged at the end of the hour, tracked with the CPUSurplusCreditsCharged metric. The instance consumes 5 credits every 5 minutes and earns 0.25, resulting in a net charge of 4.75 VCPU-minutes for each 5 minutes of bursting:

You can switch each of your instances back and forth between T2 Standard and T2 Unlimited at any time; all credit balances except CPUSurplusCreditsCharged remain and are carried over. Because T2 Unlimited instances have the ability to burst at any time, they do not receive the 30 minutes of credits given to newly launched T2 Standard instances. Also, since each AWS account can launch a limited number of T2 Standard instances with initial CPU credits each day, T2 Unlimited instances can be a better fit for use in Auto Scaling Groups and other scenarios where large numbers of instances come and go each day.

Available Now
You can launch T2 Unlimited instances today in the US East (Northern Virginia), US East (Ohio), US West (Northern California), US West (Oregon), Canada (Central), South America (São Paulo), Asia Pacific (Singapore), Asia Pacific (Sydney), Asia Pacific (Tokyo), Asia Pacific (Mumbai), Asia Pacific (Seoul), EU (Frankfurt), EU (Ireland), and EU (London) Regions today.

Jeff;

 

H1 Instances – Fast, Dense Storage for Big Data Applications

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/new-h1-instances-fast-dense-storage-for-big-data-applications/

The scale of AWS and the diversity of our customer base gives us the opportunity to create EC2 instance types that are purpose-built for many different types of workloads. For example, a number of popular big data use cases depend on high-speed, sequential access to multiple terabytes of data. Our customers want to build and run very large MapReduce clusters, host distributed file systems, use Apache Kafka to process voluminous log files, and so forth.

New H1 Instances
The new H1 instances are designed specifically for this use case. In comparison to the existing D2 (dense storage) instances, the H1 instances provide more vCPUs and more memory per terabyte of local magnetic storage, along with increased network bandwidth, giving you the power to address more complex challenges with a nicely balanced mix of resources.

The instances are based on Intel Xeon E5-2686 v4 processors running at a base clock frequency of 2.3 GHz and come in four instance sizes (all VPC-only and HVM-only):

Instance Name vCPUs
RAM
Local Storage Network Bandwidth
h1.2xlarge 8 32 GiB 2 TB Up to 10 Gbps
h1.4xlarge 16 64 GiB 4 TB Up to 10 Gbps
h1.8xlarge 32 128 GiB 8 TB 10 Gbps
h1.16xlarge 64 256 GiB 16 TB 25 Gbps

The two largest sizes support Intel Turbo and CPU power management, with all-core Turbo at 2.7 GHz and single-core Turbo at 3.0 GHz.

Local storage is optimized to deliver high throughput for sequential I/O; you can expect to transfer up to 1.15 gigabytes per second if you use a 2 megabyte block size. The storage is encrypted at rest using 256-bit XTS-AES and one-time keys.

Moving large amounts of data on and off of these instances is facilitated by the use of Enhanced Networking, giving you up to 25 Gbps of network bandwith within Placement Groups.

Launch One Today
H1 instances are available today in the US East (Northern Virginia), US West (Oregon), US East (Ohio), and EU (Ireland) Regions. You can launch them in On-Demand or Spot Form. Dedicated Hosts, Dedicated Instances, and Reserved Instances (both 1-year and 3-year) are also available.

Jeff;

M5 – The Next Generation of General-Purpose EC2 Instances

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/m5-the-next-generation-of-general-purpose-ec2-instances/

I always advise new EC2 users to start with our general-purpose instances, run some stress tests, and to get a really good feel for the compute, memory, and networking profile of their application before taking a look at other instance types. With a broad selection of instances optimized for compute, memory, and storage, our customers have many options and the flexibility to choose the instance type that is the best fit for their needs.

As you can see from my EC2 Instance History post, the general-purpose (M) instances go all the way back to 2006 when we launched the m1.small. We continued to evolve along this branch of our family tree, launching the the M2 (2009), M3 (2012), and the M4 (2015) instances. Our customers use the general-purpose instances to run web & app servers, host enterprise applications, support online games, and build cache fleets.

New M5 Instances
Today we are taking the next step forward with the launch of our new M5 instances. These instances benefit from our commitment to continued innovation and offer even better price-performance than their predecessors. Based on Custom Intel® Xeon® Platinum 8175M series processors running at 2.5 GHz, the M5 instances are designed for highly demanding workloads and will deliver 14% better price/performance than the M4 instances on a per-core basis. Applications that use the AVX-512 instructions will crank out twice as many FLOPS per core. We’ve also added a new size at the high-end, giving you even more options.

Here are the M5 instances (all VPC-only, HVM-only, and EBS-Optimized):

Instance Name vCPUs
RAM
Network Bandwidth EBS-Optimized Bandwidth
m5.large 2 8 GiB Up to 10 Gbps Up to 2120 Mbps
m5.xlarge 4 16 GiB Up to 10 Gbps Up to 2120 Mbps
m5.2xlarge 8 32 GiB Up to 10 Gbps Up to 2120 Mbps
m5.4xlarge 16 64 GiB Up to 10 Gbps 2120 Mbps
m5.12xlarge 48 192 GiB 10 Gbps 5000 Mbps
m5.24xlarge 96 384 GiB 25 Gbps 10000 Mbps

At the top end of the lineup, the m5.24xlarge is second only to the X instances when it comes to vCPU count, giving you more room to scale up and to consolidate workloads. The instances support Enhanced Networking, and can deliver up to 25 Gbps when used within a Placement Group.

In addition to dedicated, EBS-Optimized bandwidth to EBS, access to EBS storage is enhanced by the use of NVMe (you’ll need to install the proper drivers if you are using older AMIs). The combination of more bandwidth and NVMe will increase the amount of data that your M5 instances can chew through.

Launch One Today
You can launch M5 instances today in the US East (Northern Virginia), US West (Oregon), and EU (Ireland) Regions in On-Demand and Spot form (Reserved Instances are also available), with additional Regions in the works.

One quick note: the current NVMe driver is not optimized for high-performance sequential workloads and we don’t recommend the use of M5 instances in conjunction with sc1 or st1 volumes. We are aware of this issue and have been working to optimize the driver for this important use case.

Jeff;

 

 

Object models

Post Syndicated from Eevee original https://eev.ee/blog/2017/11/28/object-models/

Anonymous asks, with dollars:

More about programming languages!

Well then!

I’ve written before about what I think objects are: state and behavior, which in practice mostly means method calls.

I suspect that the popular impression of what objects are, and also how they should work, comes from whatever C++ and Java happen to do. From that point of view, the whole post above is probably nonsense. If the baseline notion of “object” is a rigid definition woven tightly into the design of two massively popular languages, then it doesn’t even make sense to talk about what “object” should mean — it does mean the features of those languages, and cannot possibly mean anything else.

I think that’s a shame! It piles a lot of baggage onto a fairly simple idea. Polymorphism, for example, has nothing to do with objects — it’s an escape hatch for static type systems. Inheritance isn’t the only way to reuse code between objects, but it’s the easiest and fastest one, so it’s what we get. Frankly, it’s much closer to a speed tradeoff than a fundamental part of the concept.

We could do with more experimentation around how objects work, but that’s impossible in the languages most commonly thought of as object-oriented.

Here, then, is a (very) brief run through the inner workings of objects in four very dynamic languages. I don’t think I really appreciated objects until I’d spent some time with Python, and I hope this can help someone else whet their own appetite.

Python 3

Of the four languages I’m going to touch on, Python will look the most familiar to the Java and C++ crowd. For starters, it actually has a class construct.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
class Vector:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def __neg__(self):
        return Vector(-self.x, -self.y)

    def __div__(self, denom):
        return Vector(self.x / denom, self.y / denom)

    @property
    def magnitude(self):
        return (self.x ** 2 + self.y ** 2) ** 0.5

    def normalized(self):
        return self / self.magnitude

The __init__ method is an initializer, which is like a constructor but named differently (because the object already exists in a usable form by the time the initializer is called). Operator overloading is done by implementing methods with other special __dunder__ names. Properties can be created with @property, where the @ is syntax for applying a wrapper function to a function as it’s defined. You can do inheritance, even multiply:

1
2
3
4
class Foo(A, B, C):
    def bar(self, x, y, z):
        # do some stuff
        super().bar(x, y, z)

Cool, a very traditional object model.

Except… for some details.

Some details

For one, Python objects don’t have a fixed layout. Code both inside and outside the class can add or remove whatever attributes they want from whatever object they want. The underlying storage is just a dict, Python’s mapping type. (Or, rather, something like one. Also, it’s possible to change, which will probably be the case for everything I say here.)

If you create some attributes at the class level, you’ll start to get a peek behind the curtains:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
class Foo:
    values = []

    def add_value(self, value):
        self.values.append(value)

a = Foo()
b = Foo()
a.add_value('a')
print(a.values)  # ['a']
b.add_value('b')
print(b.values)  # ['a', 'b']

The [] assigned to values isn’t a default assigned to each object. In fact, the individual objects don’t know about it at all! You can use vars(a) to get at the underlying storage dict, and you won’t see a values entry in there anywhere.

Instead, values lives on the class, which is a value (and thus an object) in its own right. When Python is asked for self.values, it checks to see if self has a values attribute; in this case, it doesn’t, so Python keeps going and asks the class for one.

Python’s object model is secretly prototypical — a class acts as a prototype, as a shared set of fallback values, for its objects.

In fact, this is also how method calls work! They aren’t syntactically special at all, which you can see by separating the attribute lookup from the call.

1
2
3
print("abc".startswith("a"))  # True
meth = "abc".startswith
print(meth("a"))  # True

Reading obj.method looks for a method attribute; if there isn’t one on obj, Python checks the class. Here, it finds one: it’s a function from the class body.

Ah, but wait! In the code I just showed, meth seems to “know” the object it came from, so it can’t just be a plain function. If you inspect the resulting value, it claims to be a “bound method” or “built-in method” rather than a function, too. Something funny is going on here, and that funny something is the descriptor protocol.

Descriptors

Python allows attributes to implement their own custom behavior when read from or written to. Such an attribute is called a descriptor. I’ve written about them before, but here’s a quick overview.

If Python looks up an attribute, finds it in a class, and the value it gets has a __get__ method… then instead of using that value, Python will use the return value of its __get__ method.

The @property decorator works this way. The magnitude property in my original example was shorthand for doing this:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
class MagnitudeDescriptor:
    def __get__(self, instance, owner):
        if instance is None:
            return self
        return (instance.x ** 2 + instance.y ** 2) ** 0.5

class Vector:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    magnitude = MagnitudeDescriptor()

When you ask for somevec.magnitude, Python checks somevec but doesn’t find magnitude, so it consults the class instead. The class does have a magnitude, and it’s a value with a __get__ method, so Python calls that method and somevec.magnitude evaluates to its return value. (The instance is None check is because __get__ is called even if you get the descriptor directly from the class via Vector.magnitude. A descriptor intended to work on instances can’t do anything useful in that case, so the convention is to return the descriptor itself.)

You can also intercept attempts to write to or delete an attribute, and do absolutely whatever you want instead. But note that, similar to operating overloading in Python, the descriptor must be on a class; you can’t just slap one on an arbitrary object and have it work.

This brings me right around to how “bound methods” actually work. Functions are descriptors! The function type implements __get__, and when a function is retrieved from a class via an instance, that __get__ bundles the function and the instance together into a tiny bound method object. It’s essentially:

1
2
3
4
5
class FunctionType:
    def __get__(self, instance, owner):
        if instance is None:
            return self
        return functools.partial(self, instance)

The self passed as the first argument to methods is not special or magical in any way. It’s built out of a few simple pieces that are also readily accessible to Python code.

Note also that because obj.method() is just an attribute lookup and a call, Python doesn’t actually care whether method is a method on the class or just some callable thing on the object. You won’t get the auto-self behavior if it’s on the object, but otherwise there’s no difference.

More attribute access, and the interesting part

Descriptors are one of several ways to customize attribute access. Classes can implement __getattr__ to intervene when an attribute isn’t found on an object; __setattr__ and __delattr__ to intervene when any attribute is set or deleted; and __getattribute__ to implement unconditional attribute access. (That last one is a fantastic way to create accidental recursion, since any attribute access you do within __getattribute__ will of course call __getattribute__ again.)

Here’s what I really love about Python. It might seem like a magical special case that descriptors only work on classes, but it really isn’t. You could implement exactly the same behavior yourself, in pure Python, using only the things I’ve just told you about. Classes are themselves objects, remember, and they are instances of type, so the reason descriptors only work on classes is that type effectively does this:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
class type:
    def __getattribute__(self, name):
        value = super().__getattribute__(name)
        # like all op overloads, __get__ must be on the type, not the instance
        ty = type(value)
        if hasattr(ty, '__get__'):
            # it's a descriptor!  this is a class access so there is no instance
            return ty.__get__(value, None, self)
        else:
            return value

You can even trivially prove to yourself that this is what’s going on by skipping over types behavior:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
class Descriptor:
    def __get__(self, instance, owner):
        print('called!')

class Foo:
    bar = Descriptor()

Foo.bar  # called!
type.__getattribute__(Foo, 'bar')  # called!
object.__getattribute__(Foo, 'bar')  # ...

And that’s not all! The mysterious super function, used to exhaustively traverse superclass method calls even in the face of diamond inheritance, can also be expressed in pure Python using these primitives. You could write your own superclass calling convention and use it exactly the same way as super.

This is one of the things I really like about Python. Very little of it is truly magical; virtually everything about the object model exists in the types rather than the language, which means virtually everything can be customized in pure Python.

Class creation and metaclasses

A very brief word on all of this stuff, since I could talk forever about Python and I have three other languages to get to.

The class block itself is fairly interesting. It looks like this:

1
2
class Name(*bases, **kwargs):
    # code

I’ve said several times that classes are objects, and in fact the class block is one big pile of syntactic sugar for calling type(...) with some arguments to create a new type object.

The Python documentation has a remarkably detailed description of this process, but the gist is:

  • Python determines the type of the new class — the metaclass — by looking for a metaclass keyword argument. If there isn’t one, Python uses the “lowest” type among the provided base classes. (If you’re not doing anything special, that’ll just be type, since every class inherits from object and object is an instance of type.)

  • Python executes the class body. It gets its own local scope, and any assignments or method definitions go into that scope.

  • Python now calls type(name, bases, attrs, **kwargs). The name is whatever was right after class; the bases are position arguments; and attrs is the class body’s local scope. (This is how methods and other class attributes end up on the class.) The brand new type is then assigned to Name.

Of course, you can mess with most of this. You can implement __prepare__ on a metaclass, for example, to use a custom mapping as storage for the local scope — including any reads, which allows for some interesting shenanigans. The only part you can’t really implement in pure Python is the scoping bit, which has a couple extra rules that make sense for classes. (In particular, functions defined within a class block don’t close over the class body; that would be nonsense.)

Object creation

Finally, there’s what actually happens when you create an object — including a class, which remember is just an invocation of type(...).

Calling Foo(...) is implemented as, well, a call. Any type can implement calls with the __call__ special method, and you’ll find that type itself does so. It looks something like this:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
# oh, a fun wrinkle that's hard to express in pure python: type is a class, so
# it's an instance of itself
class type:
    def __call__(self, *args, **kwargs):
        # remember, here 'self' is a CLASS, an instance of type.
        # __new__ is a true constructor: object.__new__ allocates storage
        # for a new blank object
        instance = self.__new__(self, *args, **kwargs)
        # you can return whatever you want from __new__ (!), and __init__
        # is only called on it if it's of the right type
        if isinstance(instance, self):
            instance.__init__(*args, **kwargs)
        return instance

Again, you can trivially confirm this by asking any type for its __call__ method. Assuming that type doesn’t implement __call__ itself, you’ll get back a bound version of types implementation.

1
2
>>> list.__call__
<method-wrapper '__call__' of type object at 0x7fafb831a400>

You can thus implement __call__ in your own metaclass to completely change how subclasses are created — including skipping the creation altogether, if you like.

And… there’s a bunch of stuff I haven’t even touched on.

The Python philosophy

Python offers something that, on the surface, looks like a “traditional” class/object model. Under the hood, it acts more like a prototypical system, where failed attribute lookups simply defer to a superclass or metaclass.

The language also goes to almost superhuman lengths to expose all of its moving parts. Even the prototypical behavior is an implementation of __getattribute__ somewhere, which you are free to completely replace in your own types. Proxying and delegation are easy.

Also very nice is that these features “bundle” well, by which I mean a library author can do all manner of convoluted hijinks, and a consumer of that library doesn’t have to see any of it or understand how it works. You only need to inherit from a particular class (which has a metaclass), or use some descriptor as a decorator, or even learn any new syntax.

This meshes well with Python culture, which is pretty big on the principle of least surprise. These super-advanced features tend to be tightly confined to single simple features (like “makes a weak attribute“) or cordoned with DSLs (e.g., defining a form/struct/database table with a class body). In particular, I’ve never seen a metaclass in the wild implement its own __call__.

I have mixed feelings about that. It’s probably a good thing overall that the Python world shows such restraint, but I wonder if there are some very interesting possibilities we’re missing out on. I implemented a metaclass __call__ myself, just once, in an entity/component system that strove to minimize fuss when communicating between components. It never saw the light of day, but I enjoyed seeing some new things Python could do with the same relatively simple syntax. I wouldn’t mind seeing, say, an object model based on composition (with no inheritance) built atop Python’s primitives.

Lua

Lua doesn’t have an object model. Instead, it gives you a handful of very small primitives for building your own object model. This is pretty typical of Lua — it’s a very powerful language, but has been carefully constructed to be very small at the same time. I’ve never encountered anything else quite like it, and “but it starts indexing at 1!” really doesn’t do it justice.

The best way to demonstrate how objects work in Lua is to build some from scratch. We need two key features. The first is metatables, which bear a passing resemblance to Python’s metaclasses.

Tables and metatables

The table is Lua’s mapping type and its primary data structure. Keys can be any value other than nil. Lists are implemented as tables whose keys are consecutive integers starting from 1. Nothing terribly surprising. The dot operator is sugar for indexing with a string key.

1
2
3
4
5
local t = { a = 1, b = 2 }
print(t['a'])  -- 1
print(t.b)  -- 2
t.c = 3
print(t['c'])  -- 3

A metatable is a table that can be associated with another value (usually another table) to change its behavior. For example, operator overloading is implemented by assigning a function to a special key in a metatable.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
local t = { a = 1, b = 2 }
--print(t + 0)  -- error: attempt to perform arithmetic on a table value

local mt = {
    __add = function(left, right)
        return 12
    end,
}
setmetatable(t, mt)
print(t + 0)  -- 12

Now, the interesting part: one of the special keys is __index, which is consulted when the base table is indexed by a key it doesn’t contain. Here’s a table that claims every key maps to itself.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
local t = {}
local mt = {
    __index = function(table, key)
        return key
    end,
}
setmetatable(t, mt)
print(t.foo)  -- foo
print(t.bar)  -- bar
print(t[3])  -- 3

__index doesn’t have to be a function, either. It can be yet another table, in which case that table is simply indexed with the key. If the key still doesn’t exist and that table has a metatable with an __index, the process repeats.

With this, it’s easy to have several unrelated tables that act as a single table. Call the base table an object, fill the __index table with functions and call it a class, and you have half of an object system. You can even get prototypical inheritance by chaining __indexes together.

At this point things are a little confusing, since we have at least three tables going on, so here’s a diagram. Keep in mind that Lua doesn’t actually have anything called an “object”, “class”, or “method” — those are just convenient nicknames for a particular structure we might build with Lua’s primitives.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
                    ╔═══════════╗        ...
                    ║ metatable ║         ║
                    ╟───────────╢   ┌─────╨───────────────────────┐
                    ║ __index   ╫───┤ lookup table ("superclass") │
                    ╚═══╦═══════╝   ├─────────────────────────────┤
  ╔═══════════╗         ║           │ some other method           ┼─── function() ... end
  ║ metatable ║         ║           └─────────────────────────────┘
  ╟───────────╢   ┌─────╨──────────────────┐
  ║ __index   ╫───┤ lookup table ("class") │
  ╚═══╦═══════╝   ├────────────────────────┤
      ║           │ some method            ┼─── function() ... end
      ║           └────────────────────────┘
┌─────╨─────────────────┐
│ base table ("object") │
└───────────────────────┘

Note that a metatable is not the same as a class; it defines behavior, not methods. Conversely, if you try to use a class directly as a metatable, it will probably not do much. (This is pretty different from e.g. Python, where operator overloads are just methods with funny names. One nice thing about the Lua approach is that you can keep interface-like functionality separate from methods, and avoid clogging up arbitrary objects’ namespaces. You could even use a dummy table as a key and completely avoid name collisions.)

Anyway, code!

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
local class = {
    foo = function(a)
        print("foo got", a)
    end,
}
local mt = { __index = class }
-- setmetatable returns its first argument, so this is nice shorthand
local obj1 = setmetatable({}, mt)
local obj2 = setmetatable({}, mt)
obj1.foo(7)  -- foo got 7
obj2.foo(9)  -- foo got 9

Wait, wait, hang on. Didn’t I call these methods? How do they get at the object? Maybe Lua has a magical this variable?

Methods, sort of

Not quite, but this is where the other key feature comes in: method-call syntax. It’s the lightest touch of sugar, just enough to have method invocation.

1
2
3
4
5
6
7
8
9
-- note the colon!
a:b(c, d, ...)

-- exactly equivalent to this
-- (except that `a` is only evaluated once)
a.b(a, c, d, ...)

-- which of course is really this
a["b"](a, c, d, ...)

Now we can write methods that actually do something.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
local class = {
    bar = function(self)
        print("our score is", self.score)
    end,
}
local mt = { __index = class }
local obj1 = setmetatable({ score = 13 }, mt)
local obj2 = setmetatable({ score = 25 }, mt)
obj1:bar()  -- our score is 13
obj2:bar()  -- our score is 25

And that’s all you need. Much like Python, methods and data live in the same namespace, and Lua doesn’t care whether obj:method() finds a function on obj or gets one from the metatable’s __index. Unlike Python, the function will be passed self either way, because self comes from the use of : rather than from the lookup behavior.

(Aside: strictly speaking, any Lua value can have a metatable — and if you try to index a non-table, Lua will always consult the metatable’s __index. Strings all have the string library as a metatable, so you can call methods on them: try ("%s %s"):format(1, 2). I don’t think Lua lets user code set the metatable for non-tables, so this isn’t that interesting, but if you’re writing Lua bindings from C then you can wrap your pointers in metatables to give them methods implemented in C.)

Bringing it all together

Of course, writing all this stuff every time is a little tedious and error-prone, so instead you might want to wrap it all up inside a little function. No problem.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
local function make_object(body)
    -- create a metatable
    local mt = { __index = body }
    -- create a base table to serve as the object itself
    local obj = setmetatable({}, mt)
    -- and, done
    return obj
end

-- you can leave off parens if you're only passing in 
local Dog = {
    -- this acts as a "default" value; if obj.barks is missing, __index will
    -- kick in and find this value on the class.  but if obj.barks is assigned
    -- to, it'll go in the object and shadow the value here.
    barks = 0,

    bark = function(self)
        self.barks = self.barks + 1
        print("woof!")
    end,
}

local mydog = make_object(Dog)
mydog:bark()  -- woof!
mydog:bark()  -- woof!
mydog:bark()  -- woof!
print(mydog.barks)  -- 3
print(Dog.barks)  -- 0

It works, but it’s fairly barebones. The nice thing is that you can extend it pretty much however you want. I won’t reproduce an entire serious object system here — lord knows there are enough of them floating around — but the implementation I have for my LÖVE games lets me do this:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
local Animal = Object:extend{
    cries = 0,
}

-- called automatically by Object
function Animal:init()
    print("whoops i couldn't think of anything interesting to put here")
end

-- this is just nice syntax for adding a first argument called 'self', then
-- assigning this function to Animal.cry
function Animal:cry()
    self.cries = self.cries + 1
end

local Cat = Animal:extend{}

function Cat:cry()
    print("meow!")
    Cat.__super.cry(self)
end

local cat = Cat()
cat:cry()  -- meow!
cat:cry()  -- meow!
print(cat.cries)  -- 2

When I say you can extend it however you want, I mean that. I could’ve implemented Python (2)-style super(Cat, self):cry() syntax; I just never got around to it. I could even make it work with multiple inheritance if I really wanted to — or I could go the complete opposite direction and only implement composition. I could implement descriptors, customizing the behavior of individual table keys. I could add pretty decent syntax for composition/proxying. I am trying very hard to end this section now.

The Lua philosophy

Lua’s philosophy is to… not have a philosophy? It gives you the bare minimum to make objects work, and you can do absolutely whatever you want from there. Lua does have something resembling prototypical inheritance, but it’s not so much a first-class feature as an emergent property of some very simple tools. And since you can make __index be a function, you could avoid the prototypical behavior and do something different entirely.

The very severe downside, of course, is that you have to find or build your own object system — which can get pretty confusing very quickly, what with the multiple small moving parts. Third-party code may also have its own object system with subtly different behavior. (Though, in my experience, third-party code tries very hard to avoid needing an object system at all.)

It’s hard to say what the Lua “culture” is like, since Lua is an embedded language that’s often a little different in each environment. I imagine it has a thousand millicultures, instead. I can say that the tedium of building my own object model has led me into something very “traditional”, with prototypical inheritance and whatnot. It’s partly what I’m used to, but it’s also just really dang easy to get working.

Likewise, while I love properties in Python and use them all the dang time, I’ve yet to use a single one in Lua. They wouldn’t be particularly hard to add to my object model, but having to add them myself (or shop around for an object model with them and also port all my code to use it) adds a huge amount of friction. I’ve thought about designing an interesting ECS with custom object behavior, too, but… is it really worth the effort? For all the power and flexibility Lua offers, the cost is that by the time I have something working at all, I’m too exhausted to actually use any of it.

JavaScript

JavaScript is notable for being preposterously heavily used, yet not having a class block.

Well. Okay. Yes. It has one now. It didn’t for a very long time, and even the one it has now is sugar.

Here’s a vector class again:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
class Vector {
    constructor(x, y) {
        this.x = x;
        this.y = y;
    }

    get magnitude() {
        return Math.sqrt(this.x * this.x + this.y * this.y);
    }

    dot(other) {
        return this.x * other.x + this.y * other.y;
    }
}

In “classic” JavaScript, this would be written as:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
function Vector(x, y) {
    this.x = x;
    this.y = y;
}

Object.defineProperty(Vector.prototype, 'magnitude', {
    configurable: true,
    enumerable: true,
    get: function() {
        return Math.sqrt(this.x * this.x + this.y * this.y);
    },
});


Vector.prototype.dot = function(other) {
    return this.x * other.x + this.y * other.y;
};

Hm, yes. I can see why they added class.

The JavaScript model

In JavaScript, a new type is defined in terms of a function, which is its constructor.

Right away we get into trouble here. There is a very big difference between these two invocations, which I actually completely forgot about just now after spending four hours writing about Python and Lua:

1
2
let vec = Vector(3, 4);
let vec = new Vector(3, 4);

The first calls the function Vector. It assigns some properties to this, which here is going to be window, so now you have a global x and y. It then returns nothing, so vec is undefined.

The second calls Vector with this set to a new empty object, then evaluates to that object. The result is what you’d actually expect.

(You can detect this situation with the strange new.target expression, but I have never once remembered to do so.)

From here, we have true, honest-to-god, first-class prototypical inheritance. The word “prototype” is even right there. When you write this:

1
vec.dot(vec2)

JavaScript will look for dot on vec and (presumably) not find it. It then consults vecs prototype, an object you can see for yourself by using Object.getPrototypeOf(). Since vec is a Vector, its prototype is Vector.prototype.

I stress that Vector.prototype is not the prototype for Vector. It’s the prototype for instances of Vector.

(I say “instance”, but the true type of vec here is still just object. If you want to find Vector, it’s automatically assigned to the constructor property of its own prototype, so it’s available as vec.constructor.)

Of course, Vector.prototype can itself have a prototype, in which case the process would continue if dot were not found. A common (and, arguably, very bad) way to simulate single inheritance is to set Class.prototype to an instance of a superclass to get the prototype right, then tack on the methods for Class. Nowadays we can do Object.create(Superclass.prototype).

Now that I’ve been through Python and Lua, though, this isn’t particularly surprising. I kinda spoiled it.

I suppose one difference in JavaScript is that you can tack arbitrary attributes directly onto Vector all you like, and they will remain invisible to instances since they aren’t in the prototype chain. This is kind of backwards from Lua, where you can squirrel stuff away in the metatable.

Another difference is that every single object in JavaScript has a bunch of properties already tacked on — the ones in Object.prototype. Every object (and by “object” I mean any mapping) has a prototype, and that prototype defaults to Object.prototype, and it has a bunch of ancient junk like isPrototypeOf.

(Nit: it’s possible to explicitly create an object with no prototype via Object.create(null).)

Like Lua, and unlike Python, JavaScript doesn’t distinguish between keys found on an object and keys found via a prototype. Properties can be defined on prototypes with Object.defineProperty(), but that works just as well directly on an object, too. JavaScript doesn’t have a lot of operator overloading, but some things like Symbol.iterator also work on both objects and prototypes.

About this

You may, at this point, be wondering what this is. Unlike Lua and Python (and the last language below), this is a special built-in value — a context value, invisibly passed for every function call.

It’s determined by where the function came from. If the function was the result of an attribute lookup, then this is set to the object containing that attribute. Otherwise, this is set to the global object, window. (You can also set this to whatever you want via the call method on functions.)

This decision is made lexically, i.e. from the literal source code as written. There are no Python-style bound methods. In other words:

1
2
3
4
5
// this = obj
obj.method()
// this = window
let meth = obj.method
meth()

Also, because this is reassigned on every function call, it cannot be meaningfully closed over, which makes using closures within methods incredibly annoying. The old approach was to assign this to some other regular name like self (which got syntax highlighting since it’s also a built-in name in browsers); then we got Function.bind, which produced a callable thing with a fixed context value, which was kind of nice; and now finally we have arrow functions, which explicitly close over the current this when they’re defined and don’t change it when called. Phew.

Class syntax

I already showed class syntax, and it’s really just one big macro for doing all the prototype stuff The Right Way. It even prevents you from calling the type without new. The underlying model is exactly the same, and you can inspect all the parts.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
class Vector { ... }

console.log(Vector.prototype);  // { dot: ..., magnitude: ..., ... }
let vec = new Vector(3, 4);
console.log(Object.getPrototypeOf(vec));  // same as Vector.prototype

// i don't know why you would subclass vector but let's roll with it
class Vectest extends Vector { ... }

console.log(Vectest.prototype);  // { ... }
console.log(Object.getPrototypeOf(Vectest.prototype))  // same as Vector.prototype

Alas, class syntax has a couple shortcomings. You can’t use the class block to assign arbitrary data to either the type object or the prototype — apparently it was deemed too confusing that mutations would be shared among instances. Which… is… how prototypes work. How Python works. How JavaScript itself, one of the most popular languages of all time, has worked for twenty-two years. Argh.

You can still do whatever assignment you want outside of the class block, of course. It’s just a little ugly, and not something I’d think to look for with a sugary class.

A more subtle result of this behavior is that a class block isn’t quite the same syntax as an object literal. The check for data isn’t a runtime thing; class Foo { x: 3 } fails to parse. So JavaScript now has two largely but not entirely identical styles of key/value block.

Attribute access

Here’s where things start to come apart at the seams, just a little bit.

JavaScript doesn’t really have an attribute protocol. Instead, it has two… extension points, I suppose.

One is Object.defineProperty, seen above. For common cases, there’s also the get syntax inside a property literal, which does the same thing. But unlike Python’s @property, these aren’t wrappers around some simple primitives; they are the primitives. JavaScript is the only language of these four to have “property that runs code on access” as a completely separate first-class concept.

If you want to intercept arbitrary attribute access (and some kinds of operators), there’s a completely different primitive: the Proxy type. It doesn’t let you intercept attribute access or operators; instead, it produces a wrapper object that supports interception and defers to the wrapped object by default.

It’s cool to see composition used in this way, but also, extremely weird. If you want to make your own type that overloads in or calling, you have to return a Proxy that wraps your own type, rather than actually returning your own type. And (unlike the other three languages in this post) you can’t return a different type from a constructor, so you have to throw that away and produce objects only from a factory. And instanceof would be broken, but you can at least fix that with Symbol.hasInstance — which is really operator overloading, implement yet another completely different way.

I know the design here is a result of legacy and speed — if any object could intercept all attribute access, then all attribute access would be slowed down everywhere. Fair enough. It still leaves the surface area of the language a bit… bumpy?

The JavaScript philosophy

It’s a little hard to tell. The original idea of prototypes was interesting, but it was hidden behind some very awkward syntax. Since then, we’ve gotten a bunch of extra features awkwardly bolted on to reflect the wildly varied things the built-in types and DOM API were already doing. We have class syntax, but it’s been explicitly designed to avoid exposing the prototype parts of the model.

I admit I don’t do a lot of heavy JavaScript, so I might just be overlooking it, but I’ve seen virtually no code that makes use of any of the recent advances in object capabilities. Forget about custom iterators or overloading call; I can’t remember seeing any JavaScript in the wild that even uses properties yet. I don’t know if everyone’s waiting for sufficient browser support, nobody knows about them, or nobody cares.

The model has advanced recently, but I suspect JavaScript is still shackled to its legacy of “something about prototypes, I don’t really get it, just copy the other code that’s there” as an object model. Alas! Prototypes are so good. Hopefully class syntax will make it a bit more accessible, as it has in Python.

Perl 5

Perl 5 also doesn’t have an object system and expects you to build your own. But where Lua gives you two simple, powerful tools for building one, Perl 5 feels more like a puzzle with half the pieces missing. Clearly they were going for something, but they only gave you half of it.

In brief, a Perl object is a reference that has been blessed with a package.

I need to explain a few things. Honestly, one of the biggest problems with the original Perl object setup was how many strange corners and unique jargon you had to understand just to get off the ground.

(If you want to try running any of this code, you should stick a use v5.26; as the first line. Perl is very big on backwards compatibility, so you need to opt into breaking changes, and even the mundane say builtin is behind a feature gate.)

References

A reference in Perl is sort of like a pointer, but its main use is very different. See, Perl has the strange property that its data structures try very hard to spill their contents all over the place. Despite having dedicated syntax for arrays — @foo is an array variable, distinct from the single scalar variable $foo — it’s actually impossible to nest arrays.

1
2
3
my @foo = (1, 2, 3, 4);
my @bar = (@foo, @foo);
# @bar is now a flat list of eight items: 1, 2, 3, 4, 1, 2, 3, 4

The idea, I guess, is that an array is not one thing. It’s not a container, which happens to hold multiple things; it is multiple things. Anywhere that expects a single value, such as an array element, cannot contain an array, because an array fundamentally is not a single value.

And so we have “references”, which are a form of indirection, but also have the nice property that they’re single values. They add containment around arrays, and in general they make working with most of Perl’s primitive types much more sensible. A reference to a variable can be taken with the \ operator, or you can use [ ... ] and { ... } to directly create references to anonymous arrays or hashes.

1
2
3
my @foo = (1, 2, 3, 4);
my @bar = (\@foo, \@foo);
# @bar is now a nested list of two items: [1, 2, 3, 4], [1, 2, 3, 4]

(Incidentally, this is the sole reason I initially abandoned Perl for Python. Non-trivial software kinda requires nesting a lot of data structures, so you end up with references everywhere, and the syntax for going back and forth between a reference and its contents is tedious and ugly.)

A Perl object must be a reference. Perl doesn’t care what kind of reference — it’s usually a hash reference, since hashes are a convenient place to store arbitrary properties, but it could just as well be a reference to an array, a scalar, or even a sub (i.e. function) or filehandle.

I’m getting a little ahead of myself. First, the other half: blessing and packages.

Packages and blessing

Perl packages are just namespaces. A package looks like this:

1
2
3
4
5
6
7
package Foo::Bar;

sub quux {
    say "hi from quux!";
}

# now Foo::Bar::quux() can be called from anywhere

Nothing shocking, right? It’s just a named container. A lot of the details are kind of weird, like how a package exists in some liminal quasi-value space, but the basic idea is a Bag Of Stuff.

The final piece is “blessing,” which is Perl’s funny name for binding a package to a reference. A very basic class might look like this:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
package Vector;

# the name 'new' is convention, not special
sub new {
    # perl argument passing is weird, don't ask
    my ($class, $x, $y) = @_;

    # create the object itself -- here, unusually, an array reference makes sense
    my $self = [ $x, $y ];

    # associate the package with that reference
    # note that $class here is just the regular string, 'Vector'
    bless $self, $class;

    return $self;
}

sub x {
    my ($self) = @_;
    return $self->[0];
}

sub y {
    my ($self) = @_;
    return $self->[1];
}

sub magnitude {
    my ($self) = @_;
    return sqrt($self->x ** 2 + $self->y ** 2);
}

# switch back to the "default" package
package main;

# -> is method call syntax, which passes the invocant as the first argument;
# for a package, that's just the package name
my $vec = Vector->new(3, 4);
say $vec->magnitude;  # 5

A few things of note here. First, $self->[0] has nothing to do with objects; it’s normal syntax for getting the value of a index 0 out of an array reference called $self. (Most classes are based on hashrefs and would use $self->{value} instead.) A blessed reference is still a reference and can be treated like one.

In general, -> is Perl’s dereferencey operator, but its exact behavior depends on what follows. If it’s followed by brackets, then it’ll apply the brackets to the thing in the reference: ->{} to index a hash reference, ->[] to index an array reference, and ->() to call a function reference.

But if -> is followed by an identifier, then it’s a method call. For packages, that means calling a function in the package and passing the package name as the first argument. For objects — blessed references — that means calling a function in the associated package and passing the object as the first argument.

This is a little weird! A blessed reference is a superposition of two things: its normal reference behavior, and some completely orthogonal object behavior. Also, object behavior has no notion of methods vs data; it only knows about methods. Perl lets you omit parentheses in a lot of places, including when calling a method with no arguments, so $vec->magnitude is really $vec->magnitude().

Perl’s blessing bears some similarities to Lua’s metatables, but ultimately Perl is much closer to Ruby’s “message passing” approach than the above three languages’ approaches of “get me something and maybe it’ll be callable”. (But this is no surprise — Ruby is a spiritual successor to Perl 5.)

All of this leads to one little wrinkle: how do you actually expose data? Above, I had to write x and y methods. Am I supposed to do that for every single attribute on my type?

Yes! But don’t worry, there are third-party modules to help with this incredibly fundamental task. Take Class::Accessor::Fast, so named because it’s faster than Class::Accessor:

1
2
3
package Foo;
use base qw(Class::Accessor::Fast);
__PACKAGE__->mk_accessors(qw(fred wilma barney));

(__PACKAGE__ is the lexical name of the current package; qw(...) is a list literal that splits its contents on whitespace.)

This assumes you’re using a hashref with keys of the same names as the attributes. $obj->fred will return the fred key from your hashref, and $obj->fred(4) will change it to 4.

You also, somewhat bizarrely, have to inherit from Class::Accessor::Fast. Speaking of which,

Inheritance

Inheritance is done by populating the package-global @ISA array with some number of (string) names of parent packages. Most code instead opts to write use base ...;, which does the same thing. Or, more commonly, use parent ...;, which… also… does the same thing.

Every package implicitly inherits from UNIVERSAL, which can be freely modified by Perl code.

A method can call its superclass method with the SUPER:: pseudo-package:

1
2
3
4
sub foo {
    my ($self) = @_;
    $self->SUPER::foo;
}

However, this does a depth-first search, which means it almost certainly does the wrong thing when faced with multiple inheritance. For a while the accepted solution involved a third-party module, but Perl eventually grew an alternative you have to opt into: C3, which may be more familiar to you as the order Python uses.

1
2
3
4
5
6
use mro 'c3';

sub foo {
    my ($self) = @_;
    $self->next::method;
}

Offhand, I’m not actually sure how next::method works, seeing as it was originally implemented in pure Perl code. I suspect it involves peeking at the caller’s stack frame. If so, then this is a very different style of customizability from e.g. Python — the MRO was never intended to be pluggable, and the use of a special pseudo-package means it isn’t really, but someone was determined enough to make it happen anyway.

Operator overloading and whatnot

Operator overloading looks a little weird, though really it’s pretty standard Perl.

1
2
3
4
5
6
7
8
package MyClass;

use overload '+' => \&_add;

sub _add {
    my ($self, $other, $swap) = @_;
    ...
}

use overload here is a pragma, where “pragma” means “regular-ass module that does some wizardry when imported”.

\&_add is how you get a reference to the _add sub so you can pass it to the overload module. If you just said &_add or _add, that would call it.

And that’s it; you just pass a map of operators to functions to this built-in module. No worry about name clashes or pollution, which is pretty nice. You don’t even have to give references to functions that live in the package, if you don’t want them to clog your namespace; you could put them in another package, or even inline them anonymously.

One especially interesting thing is that Perl lets you overload every operator. Perl has a lot of operators. It considers some math builtins like sqrt and trig functions to be operators, or at least operator-y enough that you can overload them. You can also overload the “file text” operators, such as -e $path to test whether a file exists. You can overload conversions, including implicit conversion to a regex. And most fascinating to me, you can overload dereferencing — that is, the thing Perl does when you say $hashref->{key} to get at the underlying hash. So a single object could pretend to be references of multiple different types, including a subref to implement callability. Neat.

Somewhat related: you can overload basic operators (indexing, etc.) on basic types (not references!) with the tie function, which is designed completely differently and looks for methods with fixed names. Go figure.

You can intercept calls to nonexistent methods by implementing a function called AUTOLOAD, within which the $AUTOLOAD global will contain the name of the method being called. Originally this feature was, I think, intended for loading binary components or large libraries on-the-fly only when needed, hence the name. Offhand I’m not sure I ever saw it used the way __getattr__ is used in Python.

Is there a way to intercept all method calls? I don’t think so, but it is Perl, so I must be forgetting something.

Actually no one does this any more

Like a decade ago, a council of elder sages sat down and put together a whole whizbang system that covers all of it: Moose.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
package Vector;
use Moose;

has x => (is => 'rw', isa => 'Int');
has y => (is => 'rw', isa => 'Int');

sub magnitude {
    my ($self) = @_;
    return sqrt($self->x ** 2 + $self->y ** 2);
}

Moose has its own way to do pretty much everything, and it’s all built on the same primitives. Moose also adds metaclasses, somehow, despite that the underlying model doesn’t actually support them? I’m not entirely sure how they managed that, but I do remember doing some class introspection with Moose and it was much nicer than the built-in way.

(If you’re wondering, the built-in way begins with looking at the hash called %Vector::. No, that’s not a typo.)

I really cannot stress enough just how much stuff Moose does, but I don’t want to delve into it here since Moose itself is not actually the language model.

The Perl philosophy

I hope you can see what I meant with what I first said about Perl, now. It has multiple inheritance with an MRO, but uses the wrong one by default. It has extensive operator overloading, which looks nothing like how inheritance works, and also some of it uses a totally different mechanism with special method names instead. It only understands methods, not data, leaving you to figure out accessors by hand.

There’s 70% of an object system here with a clear general design it was gunning for, but none of the pieces really look anything like each other. It’s weird, in a distinctly Perl way.

The result is certainly flexible, at least! It’s especially cool that you can use whatever kind of reference you want for storage, though even as I say that, I acknowledge it’s no different from simply subclassing list or something in Python. It feels different in Perl, but maybe only because it looks so different.

I haven’t written much Perl in a long time, so I don’t know what the community is like any more. Moose was already ubiquitous when I left, which you’d think would let me say “the community mostly focuses on the stuff Moose can do” — but even a decade ago, Moose could already do far more than I had ever seen done by hand in Perl. It’s always made a big deal out of roles (read: interfaces), for instance, despite that I’d never seen anyone care about them in Perl before Moose came along. Maybe their presence in Moose has made them more popular? Who knows.

Also, I wrote Perl seriously, but in the intervening years I’ve only encountered people who only ever used Perl for one-offs. Maybe it’ll come as a surprise to a lot of readers that Perl has an object model at all.

End

Well, that was fun! I hope any of that made sense.

Special mention goes to Rust, which doesn’t have an object model you can fiddle with at runtime, but does do things a little differently.

It’s been really interesting thinking about how tiny differences make a huge impact on what people do in practice. Take the choice of storage in Perl versus Python. Perl’s massively common URI class uses a string as the storage, nothing else; I haven’t seen anything like that in Python aside from markupsafe, which is specifically designed as a string type. I would guess this is partly because Perl makes you choose — using a hashref is an obvious default, but you have to make that choice one way or the other. In Python (especially 3), inheriting from object and getting dict-based storage is the obvious thing to do; the ability to use another type isn’t quite so obvious, and doing it “right” involves a tiny bit of extra work.

Or, consider that Lua could have descriptors, but the extra bit of work (especially design work) has been enough of an impediment that I’ve never implemented them. I don’t think the object implementations I’ve looked at have included them, either. Super weird!

In that light, it’s only natural that objects would be so strongly associated with the features Java and C++ attach to them. I think that makes it all the more important to play around! Look at what Moose has done. No, really, you should bear in mind my description of how Perl does stuff and flip through the Moose documentation. It’s amazing what they’ve built.

Amazon EC2 Bare Metal Instances with Direct Access to Hardware

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/new-amazon-ec2-bare-metal-instances-with-direct-access-to-hardware/

When customers come to us with new and unique requirements for AWS, we listen closely, ask lots of questions, and do our best to understand and address their needs. When we do this, we make the resulting service or feature generally available; we do not build one-offs or “snowflakes” for individual customers. That model is messy and hard to scale and is not the way we work.

Instead, every AWS customer has access to whatever it is that we build, and everyone benefits. VMware Cloud on AWS is a good example of this strategy in action. They told us that they wanted to run their virtualization stack directly on the hardware, within the AWS Cloud, giving their customers access to the elasticity, security, and reliability (not to mention the broad array of services) that AWS offers.

We knew that other customers also had interesting use cases for bare metal hardware and didn’t want to take the performance hit of nested virtualization. They wanted access to the physical resources for applications that take advantage of low-level hardware features such as performance counters and Intel® VT that are not always available or fully supported in virtualized environments, and also for applications intended to run directly on the hardware or licensed and supported for use in non-virtualized environments.

Our multi-year effort to move networking, storage, and other EC2 features out of our virtualization platform and into dedicated hardware was already well underway and provided the perfect foundation for a possible solution. This work, as I described in Now Available – Compute-Intensive C5 Instances for Amazon EC2, includes a set of dedicated hardware accelerators.

Now that we have provided VMware with the bare metal access that they requested, we are doing the same for all AWS customers. I’m really looking forward to seeing what you can do with them!

New Bare Metal Instances
Today we are launching a public preview the i3.metal instance, the first in a series of EC2 instances that offer the best of both worlds, allowing the operating system to run directly on the underlying hardware while still providing access to all of the benefits of the cloud. The instance gives you direct access to the processor and other hardware, and has the following specifications:

  • Processing – Two Intel Xeon E5-2686 v4 processors running at 2.3 GHz, with a total of 36 hyperthreaded cores (72 logical processors).
  • Memory – 512 GiB.
  • Storage – 15.2 terabytes of local, SSD-based NVMe storage.
  • Network – 25 Gbps of ENA-based enhanced networking.

Bare Metal instances are full-fledged members of the EC2 family and can take advantage of Elastic Load Balancing, Auto Scaling, Amazon CloudWatch, Auto Recovery, and so forth. They can also access the full suite of AWS database, IoT, mobile, analytics, artificial intelligence, and security services.

Previewing Now
We are launching a public preview of the Bare Metal instances today; please sign up now if you want to try them out.

You can now bring your specialized applications or your own stack of virtualized components to AWS and run them on Bare Metal instances. If you are using or thinking about using containers, these instances make a great host for CoreOS.

An AMI that works on one of the new C5 instances should also work on an I3 Bare Metal Instance. It must have the ENA and NVMe drivers, and must be tagged for ENA.

Jeff;

 

Raspberry Pi clusters come of age

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/raspberry-pi-clusters-come-of-age/

In today’s guest post, Bruce Tulloch, CEO and Managing Director of BitScope Designs, discusses the uses of cluster computing with the Raspberry Pi, and the recent pilot of the Los Alamos National Laboratory 3000-Pi cluster built with the BitScope Blade.

Raspberry Pi cluster

High-performance computing and Raspberry Pi are not normally uttered in the same breath, but Los Alamos National Laboratory is building a Raspberry Pi cluster with 3000 cores as a pilot before scaling up to 40 000 cores or more next year.

That’s amazing, but why?

I was asked this question more than any other at The International Conference for High-Performance Computing, Networking, Storage and Analysis in Denver last week, where one of the Los Alamos Raspberry Pi Cluster Modules was on display at the University of New Mexico’s Center for Advanced Research Computing booth.

The short answer to this question is: the Raspberry Pi cluster enables Los Alamos National Laboratory (LANL) to conduct exascale computing R&D.

The Pi cluster breadboard

Exascale refers to computing systems at least 50 times faster than the most powerful supercomputers in use today. The problem faced by LANL and similar labs building these things is one of scale. To get the required performance, you need a lot of nodes, and to make it work, you need a lot of R&D.

However, there’s a catch-22: how do you write the operating systems, networks stacks, launch and boot systems for such large computers without having one on which to test it all? Use an existing supercomputer? No — the existing large clusters are fully booked 24/7 doing science, they cost millions of dollars per year to run, and they may not have the architecture you need for your next-generation machine anyway. Older machines retired from science may be available, but at this scale they cost far too much to use and are usually very hard to maintain.

The Los Alamos solution? Build a “model supercomputer” with Raspberry Pi!

Think of it as a “cluster development breadboard”.

The idea is to design, develop, debug, and test new network architectures and systems software on the “breadboard”, but at a scale equivalent to the production machines you’re currently building. Raspberry Pi may be a small computer, but it can run most of the system software stacks that production machines use, and the ratios of its CPU speed, local memory, and network bandwidth scale proportionately to the big machines, much like an architect’s model does when building a new house. To learn more about the project, see the news conference and this interview with insideHPC at SC17.

Traditional Raspberry Pi clusters

Like most people, we love a good cluster! People have been building them with Raspberry Pi since the beginning, because it’s inexpensive, educational, and fun. They’ve been built with the original Pi, Pi 2, Pi 3, and even the Pi Zero, but none of these clusters have proven to be particularly practical.

That’s not stopped them being useful though! I saw quite a few Raspberry Pi clusters at the conference last week.

One tiny one that caught my eye was from the people at openio.io, who used a small Raspberry Pi Zero W cluster to demonstrate their scalable software-defined object storage platform, which on big machines is used to manage petabytes of data, but which is so lightweight that it runs just fine on this:

Raspberry Pi Zero cluster

There was another appealing example at the ARM booth, where the Berkeley Labs’ singularity container platform was demonstrated running very effectively on a small cluster built with Raspberry Pi 3s.

Raspberry Pi 3 cluster demo at a conference stall

My show favourite was from the Edinburgh Parallel Computing Center (EPCC): Nick Brown used a cluster of Pi 3s to explain supercomputers to kids with an engaging interactive application. The idea was that visitors to the stand design an aircraft wing, simulate it across the cluster, and work out whether an aircraft that uses the new wing could fly from Edinburgh to New York on a full tank of fuel. Mine made it, fortunately!

Raspberry Pi 3 cluster demo at a conference stall

Next-generation Raspberry Pi clusters

We’ve been building small-scale industrial-strength Raspberry Pi clusters for a while now with BitScope Blade.

When Los Alamos National Laboratory approached us via HPC provider SICORP with a request to build a cluster comprising many thousands of nodes, we considered all the options very carefully. It needed to be dense, reliable, low-power, and easy to configure and to build. It did not need to “do science”, but it did need to work in almost every other way as a full-scale HPC cluster would.

Some people argue Compute Module 3 is the ideal cluster building block. It’s very small and just as powerful as Raspberry Pi 3, so one could, in theory, pack a lot of them into a very small space. However, there are very good reasons no one has ever successfully done this. For a start, you need to build your own network fabric and I/O, and cooling the CM3s, especially when densely packed in a cluster, is tricky given their tiny size. There’s very little room for heatsinks, and the tiny PCBs dissipate very little excess heat.

Instead, we saw the potential for Raspberry Pi 3 itself to be used to build “industrial-strength clusters” with BitScope Blade. It works best when the Pis are properly mounted, powered reliably, and cooled effectively. It’s important to avoid using micro SD cards and to connect the nodes using wired networks. It has the added benefit of coming with lots of “free” USB I/O, and the Pi 3 PCB, when mounted with the correct air-flow, is a remarkably good heatsink.

When Gordon announced netboot support, we became convinced the Raspberry Pi 3 was the ideal candidate when used with standard switches. We’d been making smaller clusters for a while, but netboot made larger ones practical. Assembling them all into compact units that fit into existing racks with multiple 10 Gb uplinks is the solution that meets LANL’s needs. This is a 60-node cluster pack with a pair of managed switches by Ubiquiti in testing in the BitScope Lab:

60-node Raspberry Pi cluster pack

Two of these packs, built with Blade Quattro, and one smaller one comprising 30 nodes, built with Blade Duo, are the components of the Cluster Module we exhibited at the show. Five of these modules are going into Los Alamos National Laboratory for their pilot as I write this.

Bruce Tulloch at a conference stand with a demo of the Raspberry Pi cluster for LANL

It’s not only research clusters like this for which Raspberry Pi is well suited. You can build very reliable local cloud computing and data centre solutions for research, education, and even some industrial applications. You’re not going to get much heavy-duty science, big data analytics, AI, or serious number crunching done on one of these, but it is quite amazing to see just how useful Raspberry Pi clusters can be for other purposes, whether it’s software-defined networks, lightweight MaaS, SaaS, PaaS, or FaaS solutions, distributed storage, edge computing, industrial IoT, and of course, education in all things cluster and parallel computing. For one live example, check out Mythic Beasts’ educational compute cloud, built with Raspberry Pi 3.

For more information about Raspberry Pi clusters, drop by BitScope Clusters.

I’ll read and respond to your thoughts in the comments below this post too.

Editor’s note:

Here is a photo of Bruce wearing a jetpack. Cool, right?!

Bruce Tulloch wearing a jetpack

The post Raspberry Pi clusters come of age appeared first on Raspberry Pi.

Potential impact of the Intel ME vulnerability

Post Syndicated from Matthew Garrett original https://mjg59.dreamwidth.org/49611.html

(Note: this is my personal opinion based on public knowledge around this issue. I have no knowledge of any non-public details of these vulnerabilities, and this should not be interpreted as the position or opinion of my employer)

Intel’s Management Engine (ME) is a small coprocessor built into the majority of Intel CPUs[0]. Older versions were based on the ARC architecture[1] running an embedded realtime operating system, but from version 11 onwards they’ve been small x86 cores running Minix. The precise capabilities of the ME have not been publicly disclosed, but it is at minimum capable of interacting with the network[2], display[3], USB, input devices and system flash. In other words, software running on the ME is capable of doing a lot, without requiring any OS permission in the process.

Back in May, Intel announced a vulnerability in the Advanced Management Technology (AMT) that runs on the ME. AMT offers functionality like providing a remote console to the system (so IT support can connect to your system and interact with it as if they were physically present), remote disk support (so IT support can reinstall your machine over the network) and various other bits of system management. The vulnerability meant that it was possible to log into systems with enabled AMT with an empty authentication token, making it possible to log in without knowing the configured password.

This vulnerability was less serious than it could have been for a couple of reasons – the first is that “consumer”[4] systems don’t ship with AMT, and the second is that AMT is almost always disabled (Shodan found only a few thousand systems on the public internet with AMT enabled, out of many millions of laptops). I wrote more about it here at the time.

How does this compare to the newly announced vulnerabilities? Good question. Two of the announced vulnerabilities are in AMT. The previous AMT vulnerability allowed you to bypass authentication, but restricted you to doing what AMT was designed to let you do. While AMT gives an authenticated user a great deal of power, it’s also designed with some degree of privacy protection in mind – for instance, when the remote console is enabled, an animated warning border is drawn on the user’s screen to alert them.

This vulnerability is different in that it allows an authenticated attacker to execute arbitrary code within the AMT process. This means that the attacker shouldn’t have any capabilities that AMT doesn’t, but it’s unclear where various aspects of the privacy protection are implemented – for instance, if the warning border is implemented in AMT rather than in hardware, an attacker could duplicate that functionality without drawing the warning. If the USB storage emulation for remote booting is implemented as a generic USB passthrough, the attacker could pretend to be an arbitrary USB device and potentially exploit the operating system through bugs in USB device drivers. Unfortunately we don’t currently know.

Note that this exploit still requires two things – first, AMT has to be enabled, and second, the attacker has to be able to log into AMT. If the attacker has physical access to your system and you don’t have a BIOS password set, they will be able to enable it – however, if AMT isn’t enabled and the attacker isn’t physically present, you’re probably safe. But if AMT is enabled and you haven’t patched the previous vulnerability, the attacker will be able to access AMT over the network without a password and then proceed with the exploit. This is bad, so you should probably (1) ensure that you’ve updated your BIOS and (2) ensure that AMT is disabled unless you have a really good reason to use it.

The AMT vulnerability applies to a wide range of versions, everything from version 6 (which shipped around 2008) and later. The other vulnerability that Intel describe is restricted to version 11 of the ME, which only applies to much more recent systems. This vulnerability allows an attacker to execute arbitrary code on the ME, which means they can do literally anything the ME is able to do. This probably also means that they are able to interfere with any other code running on the ME. While AMT has been the most frequently discussed part of this, various other Intel technologies are tied to ME functionality.

Intel’s Platform Trust Technology (PTT) is a software implementation of a Trusted Platform Module (TPM) that runs on the ME. TPMs are intended to protect access to secrets and encryption keys and record the state of the system as it boots, making it possible to determine whether a system has had part of its boot process modified and denying access to the secrets as a result. The most common usage of TPMs is to protect disk encryption keys – Microsoft Bitlocker defaults to storing its encryption key in the TPM, automatically unlocking the drive if the boot process is unmodified. In addition, TPMs support something called Remote Attestation (I wrote about that here), which allows the TPM to provide a signed copy of information about what the system booted to a remote site. This can be used for various purposes, such as not allowing a compute node to join a cloud unless it’s booted the correct version of the OS and is running the latest firmware version. Remote Attestation depends on the TPM having a unique cryptographic identity that is tied to the TPM and inaccessible to the OS.

PTT allows manufacturers to simply license some additional code from Intel and run it on the ME rather than having to pay for an additional chip on the system motherboard. This seems great, but if an attacker is able to run code on the ME then they potentially have the ability to tamper with PTT, which means they can obtain access to disk encryption secrets and circumvent Bitlocker. It also means that they can tamper with Remote Attestation, “attesting” that the system booted a set of software that it didn’t or copying the keys to another system and allowing that to impersonate the first. This is, uh, bad.

Intel also recently announced Intel Online Connect, a mechanism for providing the functionality of security keys directly in the operating system. Components of this are run on the ME in order to avoid scenarios where a compromised OS could be used to steal the identity secrets – if the ME is compromised, this may make it possible for an attacker to obtain those secrets and duplicate the keys.

It’s also not entirely clear how much of Intel’s Secure Guard Extensions (SGX) functionality depends on the ME. The ME does appear to be required for SGX Remote Attestation (which allows an application using SGX to prove to a remote site that it’s the SGX app rather than something pretending to be it), and again if those secrets can be extracted from a compromised ME it may be possible to compromise some of the security assumptions around SGX. Again, it’s not clear how serious this is because it’s not publicly documented.

Various other things also run on the ME, including stuff like video DRM (ensuring that high resolution video streams can’t be intercepted by the OS). It may be possible to obtain encryption keys from a compromised ME that allow things like Netflix streams to be decoded and dumped. From a user privacy or security perspective, these things seem less serious.

The big problem at the moment is that we have no idea what the actual process of compromise is. Intel state that it requires local access, but don’t describe what kind. Local access in this case could simply require the ability to send commands to the ME (possible on any system that has the ME drivers installed), could require direct hardware access to the exposed ME (which would require either kernel access or the ability to install a custom driver) or even the ability to modify system flash (possible only if the attacker has physical access and enough time and skill to take the system apart and modify the flash contents with an SPI programmer). The other thing we don’t know is whether it’s possible for an attacker to modify the system such that the ME is persistently compromised or whether it needs to be re-compromised every time the ME reboots. Note that even the latter is more serious than you might think – the ME may only be rebooted if the system loses power completely, so even a “temporary” compromise could affect a system for a long period of time.

It’s also almost impossible to determine if a system is compromised. If the ME is compromised then it’s probably possible for it to roll back any firmware updates but still report that it’s been updated, giving admins a false sense of security. The only way to determine for sure would be to dump the system flash and compare it to a known good image. This is impractical to do at scale.

So, overall, given what we know right now it’s hard to say how serious this is in terms of real world impact. It’s unlikely that this is the kind of vulnerability that would be used to attack individual end users – anyone able to compromise a system like this could just backdoor your browser instead with much less effort, and that already gives them your banking details. The people who have the most to worry about here are potential targets of skilled attackers, which means activists, dissidents and companies with interesting personal or business data. It’s hard to make strong recommendations about what to do here without more insight into what the vulnerability actually is, and we may not know that until this presentation next month.

Summary: Worst case here is terrible, but unlikely to be relevant to the vast majority of users.

[0] Earlier versions of the ME were built into the motherboard chipset, but as portions of that were incorporated onto the CPU package the ME followed
[1] A descendent of the SuperFX chip used in Super Nintendo cartridges such as Starfox, because why not
[2] Without any OS involvement for wired ethernet and for wireless networks in the system firmware, but requires OS support for wireless access once the OS drivers have loaded
[3] Assuming you’re using integrated Intel graphics
[4] “Consumer” is a bit of a misnomer here – “enterprise” laptops like Thinkpads ship with AMT, but are often bought by consumers.

comment count unavailable comments

Using Amazon Redshift Spectrum, Amazon Athena, and AWS Glue with Node.js in Production

Post Syndicated from Rafi Ton original https://aws.amazon.com/blogs/big-data/using-amazon-redshift-spectrum-amazon-athena-and-aws-glue-with-node-js-in-production/

This is a guest post by Rafi Ton, founder and CEO of NUVIAD. NUVIAD is, in their own words, “a mobile marketing platform providing professional marketers, agencies and local businesses state of the art tools to promote their products and services through hyper targeting, big data analytics and advanced machine learning tools.”

At NUVIAD, we’ve been using Amazon Redshift as our main data warehouse solution for more than 3 years.

We store massive amounts of ad transaction data that our users and partners analyze to determine ad campaign strategies. When running real-time bidding (RTB) campaigns in large scale, data freshness is critical so that our users can respond rapidly to changes in campaign performance. We chose Amazon Redshift because of its simplicity, scalability, performance, and ability to load new data in near real time.

Over the past three years, our customer base grew significantly and so did our data. We saw our Amazon Redshift cluster grow from three nodes to 65 nodes. To balance cost and analytics performance, we looked for a way to store large amounts of less-frequently analyzed data at a lower cost. Yet, we still wanted to have the data immediately available for user queries and to meet their expectations for fast performance. We turned to Amazon Redshift Spectrum.

In this post, I explain the reasons why we extended Amazon Redshift with Redshift Spectrum as our modern data warehouse. I cover how our data growth and the need to balance cost and performance led us to adopt Redshift Spectrum. I also share key performance metrics in our environment, and discuss the additional AWS services that provide a scalable and fast environment, with data available for immediate querying by our growing user base.

Amazon Redshift as our foundation

The ability to provide fresh, up-to-the-minute data to our customers and partners was always a main goal with our platform. We saw other solutions provide data that was a few hours old, but this was not good enough for us. We insisted on providing the freshest data possible. For us, that meant loading Amazon Redshift in frequent micro batches and allowing our customers to query Amazon Redshift directly to get results in near real time.

The benefits were immediately evident. Our customers could see how their campaigns performed faster than with other solutions, and react sooner to the ever-changing media supply pricing and availability. They were very happy.

However, this approach required Amazon Redshift to store a lot of data for long periods, and our data grew substantially. In our peak, we maintained a cluster running 65 DC1.large nodes. The impact on our Amazon Redshift cluster was evident, and we saw our CPU utilization grow to 90%.

Why we extended Amazon Redshift to Redshift Spectrum

Redshift Spectrum gives us the ability to run SQL queries using the powerful Amazon Redshift query engine against data stored in Amazon S3, without needing to load the data. With Redshift Spectrum, we store data where we want, at the cost that we want. We have the data available for analytics when our users need it with the performance they expect.

Seamless scalability, high performance, and unlimited concurrency

Scaling Redshift Spectrum is a simple process. First, it allows us to leverage Amazon S3 as the storage engine and get practically unlimited data capacity.

Second, if we need more compute power, we can leverage Redshift Spectrum’s distributed compute engine over thousands of nodes to provide superior performance – perfect for complex queries running against massive amounts of data.

Third, all Redshift Spectrum clusters access the same data catalog so that we don’t have to worry about data migration at all, making scaling effortless and seamless.

Lastly, since Redshift Spectrum distributes queries across potentially thousands of nodes, they are not affected by other queries, providing much more stable performance and unlimited concurrency.

Keeping it SQL

Redshift Spectrum uses the same query engine as Amazon Redshift. This means that we did not need to change our BI tools or query syntax, whether we used complex queries across a single table or joins across multiple tables.

An interesting capability introduced recently is the ability to create a view that spans both Amazon Redshift and Redshift Spectrum external tables. With this feature, you can query frequently accessed data in your Amazon Redshift cluster and less-frequently accessed data in Amazon S3, using a single view.

Leveraging Parquet for higher performance

Parquet is a columnar data format that provides superior performance and allows Redshift Spectrum (or Amazon Athena) to scan significantly less data. With less I/O, queries run faster and we pay less per query. You can read all about Parquet at https://parquet.apache.org/ or https://en.wikipedia.org/wiki/Apache_Parquet.

Lower cost

From a cost perspective, we pay standard rates for our data in Amazon S3, and only small amounts per query to analyze data with Redshift Spectrum. Using the Parquet format, we can significantly reduce the amount of data scanned. Our costs are now lower, and our users get fast results even for large complex queries.

What we learned about Amazon Redshift vs. Redshift Spectrum performance

When we first started looking at Redshift Spectrum, we wanted to put it to the test. We wanted to know how it would compare to Amazon Redshift, so we looked at two key questions:

  1. What is the performance difference between Amazon Redshift and Redshift Spectrum on simple and complex queries?
  2. Does the data format impact performance?

During the migration phase, we had our dataset stored in Amazon Redshift and S3 as CSV/GZIP and as Parquet file formats. We tested three configurations:

  • Amazon Redshift cluster with 28 DC1.large nodes
  • Redshift Spectrum using CSV/GZIP
  • Redshift Spectrum using Parquet

We performed benchmarks for simple and complex queries on one month’s worth of data. We tested how much time it took to perform the query, and how consistent the results were when running the same query multiple times. The data we used for the tests was already partitioned by date and hour. Properly partitioning the data improves performance significantly and reduces query times.

Simple query

First, we tested a simple query aggregating billing data across a month:

SELECT 
  user_id, 
  count(*) AS impressions, 
  SUM(billing)::decimal /1000000 AS billing 
FROM <table_name> 
WHERE 
  date >= '2017-08-01' AND 
  date <= '2017-08-31'  
GROUP BY 
  user_id;

We ran the same query seven times and measured the response times (red marking the longest time and green the shortest time):

Execution Time (seconds)
  Amazon Redshift Redshift Spectrum
CSV
Redshift Spectrum Parquet
Run #1 39.65 45.11 11.92
Run #2 15.26 43.13 12.05
Run #3 15.27 46.47 13.38
Run #4 21.22 51.02 12.74
Run #5 17.27 43.35 11.76
Run #6 16.67 44.23 13.67
Run #7 25.37 40.39 12.75
Average 21.53  44.82 12.61

For simple queries, Amazon Redshift performed better than Redshift Spectrum, as we thought, because the data is local to Amazon Redshift.

What was surprising was that using Parquet data format in Redshift Spectrum significantly beat ‘traditional’ Amazon Redshift performance. For our queries, using Parquet data format with Redshift Spectrum delivered an average 40% performance gain over traditional Amazon Redshift. Furthermore, Redshift Spectrum showed high consistency in execution time with a smaller difference between the slowest run and the fastest run.

Comparing the amount of data scanned when using CSV/GZIP and Parquet, the difference was also significant:

Data Scanned (GB)
CSV (Gzip) 135.49
Parquet 2.83

Because we pay only for the data scanned by Redshift Spectrum, the cost saving of using Parquet is evident and substantial.

Complex query

Next, we compared the same three configurations with a complex query.

Execution Time (seconds)
  Amazon Redshift Redshift Spectrum CSV Redshift Spectrum Parquet
Run #1 329.80 84.20 42.40
Run #2 167.60 65.30 35.10
Run #3 165.20 62.20 23.90
Run #4 273.90 74.90 55.90
Run #5 167.70 69.00 58.40
Average 220.84 71.12 43.14

This time, Redshift Spectrum using Parquet cut the average query time by 80% compared to traditional Amazon Redshift!

Bottom line: For complex queries, Redshift Spectrum provided a 67% performance gain over Amazon Redshift. Using the Parquet data format, Redshift Spectrum delivered an 80% performance improvement over Amazon Redshift. For us, this was substantial.

Optimizing the data structure for different workloads

Because the cost of S3 is relatively inexpensive and we pay only for the data scanned by each query, we believe that it makes sense to keep our data in different formats for different workloads and different analytics engines. It is important to note that we can have any number of tables pointing to the same data on S3. It all depends on how we partition the data and update the table partitions.

Data permutations

For example, we have a process that runs every minute and generates statistics for the last minute of data collected. With Amazon Redshift, this would be done by running the query on the table with something as follows:

SELECT 
  user, 
  COUNT(*) 
FROM 
  events_table 
WHERE 
  ts BETWEEN ‘2017-08-01 14:00:00’ AND ‘2017-08-01 14:00:59’ 
GROUP BY 
  user;

(Assuming ‘ts’ is your column storing the time stamp for each event.)

With Redshift Spectrum, we pay for the data scanned in each query. If the data is partitioned by the minute instead of the hour, a query looking at one minute would be 1/60th the cost. If we use a temporary table that points only to the data of the last minute, we save that unnecessary cost.

Creating Parquet data efficiently

On the average, we have 800 instances that process our traffic. Each instance sends events that are eventually loaded into Amazon Redshift. When we started three years ago, we would offload data from each server to S3 and then perform a periodic copy command from S3 to Amazon Redshift.

Recently, Amazon Kinesis Firehose added the capability to offload data directly to Amazon Redshift. While this is now a viable option, we kept the same collection process that worked flawlessly and efficiently for three years.

This changed, however, when we incorporated Redshift Spectrum. With Redshift Spectrum, we needed to find a way to:

  • Collect the event data from the instances.
  • Save the data in Parquet format.
  • Partition the data effectively.

To accomplish this, we save the data as CSV and then transform it to Parquet. The most effective method to generate the Parquet files is to:

  1. Send the data in one-minute intervals from the instances to Kinesis Firehose with an S3 temporary bucket as the destination.
  2. Aggregate hourly data and convert it to Parquet using AWS Lambda and AWS Glue.
  3. Add the Parquet data to S3 by updating the table partitions.

With this new process, we had to give more attention to validating the data before we sent it to Kinesis Firehose, because a single corrupted record in a partition fails queries on that partition.

Data validation

To store our click data in a table, we considered the following SQL create table command:

create external TABLE spectrum.blog_clicks (
    user_id varchar(50),
    campaign_id varchar(50),
    os varchar(50),
    ua varchar(255),
    ts bigint,
    billing float
)
partitioned by (date date, hour smallint)  
stored as parquet
location 's3://nuviad-temp/blog/clicks/';

The above statement defines a new external table (all Redshift Spectrum tables are external tables) with a few attributes. We stored ‘ts’ as a Unix time stamp and not as Timestamp, and billing data is stored as float and not decimal (more on that later). We also said that the data is partitioned by date and hour, and then stored as Parquet on S3.

First, we need to get the table definitions. This can be achieved by running the following query:

SELECT 
  * 
FROM 
  svv_external_columns 
WHERE 
  tablename = 'blog_clicks';

This query lists all the columns in the table with their respective definitions:

schemaname tablename columnname external_type columnnum part_key
spectrum blog_clicks user_id varchar(50) 1 0
spectrum blog_clicks campaign_id varchar(50) 2 0
spectrum blog_clicks os varchar(50) 3 0
spectrum blog_clicks ua varchar(255) 4 0
spectrum blog_clicks ts bigint 5 0
spectrum blog_clicks billing double 6 0
spectrum blog_clicks date date 7 1
spectrum blog_clicks hour smallint 8 2

Now we can use this data to create a validation schema for our data:

const rtb_request_schema = {
    "name": "clicks",
    "items": {
        "user_id": {
            "type": "string",
            "max_length": 100
        },
        "campaign_id": {
            "type": "string",
            "max_length": 50
        },
        "os": {
            "type": "string",
            "max_length": 50            
        },
        "ua": {
            "type": "string",
            "max_length": 255            
        },
        "ts": {
            "type": "integer",
            "min_value": 0,
            "max_value": 9999999999999
        },
        "billing": {
            "type": "float",
            "min_value": 0,
            "max_value": 9999999999999
        }
    }
};

Next, we create a function that uses this schema to validate data:

function valueIsValid(value, item_schema) {
    if (schema.type == 'string') {
        return (typeof value == 'string' && value.length <= schema.max_length);
    }
    else if (schema.type == 'integer') {
        return (typeof value == 'number' && value >= schema.min_value && value <= schema.max_value);
    }
    else if (schema.type == 'float' || schema.type == 'double') {
        return (typeof value == 'number' && value >= schema.min_value && value <= schema.max_value);
    }
    else if (schema.type == 'boolean') {
        return typeof value == 'boolean';
    }
    else if (schema.type == 'timestamp') {
        return (new Date(value)).getTime() > 0;
    }
    else {
        return true;
    }
}

Near real-time data loading with Kinesis Firehose

On Kinesis Firehose, we created a new delivery stream to handle the events as follows:

Delivery stream name: events
Source: Direct PUT
S3 bucket: nuviad-events
S3 prefix: rtb/
IAM role: firehose_delivery_role_1
Data transformation: Disabled
Source record backup: Disabled
S3 buffer size (MB): 100
S3 buffer interval (sec): 60
S3 Compression: GZIP
S3 Encryption: No Encryption
Status: ACTIVE
Error logging: Enabled

This delivery stream aggregates event data every minute, or up to 100 MB, and writes the data to an S3 bucket as a CSV/GZIP compressed file. Next, after we have the data validated, we can safely send it to our Kinesis Firehose API:

if (validated) {
    let itemString = item.join('|')+'\n'; //Sending csv delimited by pipe and adding new line

    let params = {
        DeliveryStreamName: 'events',
        Record: {
            Data: itemString
        }
    };

    firehose.putRecord(params, function(err, data) {
        if (err) {
            console.error(err, err.stack);        
        }
        else {
            // Continue to your next step 
        }
    });
}

Now, we have a single CSV file representing one minute of event data stored in S3. The files are named automatically by Kinesis Firehose by adding a UTC time prefix in the format YYYY/MM/DD/HH before writing objects to S3. Because we use the date and hour as partitions, we need to change the file naming and location to fit our Redshift Spectrum schema.

Automating data distribution using AWS Lambda

We created a simple Lambda function triggered by an S3 put event that copies the file to a different location (or locations), while renaming it to fit our data structure and processing flow. As mentioned before, the files generated by Kinesis Firehose are structured in a pre-defined hierarchy, such as:

S3://your-bucket/your-prefix/2017/08/01/20/events-4-2017-08-01-20-06-06-536f5c40-6893-4ee4-907d-81e4d3b09455.gz

All we need to do is parse the object name and restructure it as we see fit. In our case, we did the following (the event is an object received in the Lambda function with all the data about the object written to S3):

/*
	object key structure in the event object:
your-prefix/2017/08/01/20/event-4-2017-08-01-20-06-06-536f5c40-6893-4ee4-907d-81e4d3b09455.gz
	*/

let key_parts = event.Records[0].s3.object.key.split('/'); 

let event_type = key_parts[0];
let date = key_parts[1] + '-' + key_parts[2] + '-' + key_parts[3];
let hour = key_parts[4];
if (hour.indexOf('0') == 0) {
 		hour = parseInt(hour, 10) + '';
}
    
let parts1 = key_parts[5].split('-');
let minute = parts1[7];
if (minute.indexOf('0') == 0) {
        minute = parseInt(minute, 10) + '';
}

Now, we can redistribute the file to the two destinations we need—one for the minute processing task and the other for hourly aggregation:

    copyObjectToHourlyFolder(event, date, hour, minute)
        .then(copyObjectToMinuteFolder.bind(null, event, date, hour, minute))
        .then(addPartitionToSpectrum.bind(null, event, date, hour, minute))
        .then(deleteOldMinuteObjects.bind(null, event))
        .then(deleteStreamObject.bind(null, event))        
        .then(result => {
            callback(null, { message: 'done' });            
        })
        .catch(err => {
            console.error(err);
            callback(null, { message: err });            
        }); 

Kinesis Firehose stores the data in a temporary folder. We copy the object to another folder that holds the data for the last processed minute. This folder is connected to a small Redshift Spectrum table where the data is being processed without needing to scan a much larger dataset. We also copy the data to a folder that holds the data for the entire hour, to be later aggregated and converted to Parquet.

Because we partition the data by date and hour, we created a new partition on the Redshift Spectrum table if the processed minute is the first minute in the hour (that is, minute 0). We ran the following:

ALTER TABLE 
  spectrum.events 
ADD partition
  (date='2017-08-01', hour=0) 
  LOCATION 's3://nuviad-temp/events/2017-08-01/0/';

After the data is processed and added to the table, we delete the processed data from the temporary Kinesis Firehose storage and from the minute storage folder.

Migrating CSV to Parquet using AWS Glue and Amazon EMR

The simplest way we found to run an hourly job converting our CSV data to Parquet is using Lambda and AWS Glue (and thanks to the awesome AWS Big Data team for their help with this).

Creating AWS Glue jobs

What this simple AWS Glue script does:

  • Gets parameters for the job, date, and hour to be processed
  • Creates a Spark EMR context allowing us to run Spark code
  • Reads CSV data into a DataFrame
  • Writes the data as Parquet to the destination S3 bucket
  • Adds or modifies the Redshift Spectrum / Amazon Athena table partition for the table
import sys
import sys
from awsglue.transforms import *
from awsglue.utils import getResolvedOptions
from pyspark.context import SparkContext
from awsglue.context import GlueContext
from awsglue.job import Job
import boto3

## @params: [JOB_NAME]
args = getResolvedOptions(sys.argv, ['JOB_NAME','day_partition_key', 'hour_partition_key', 'day_partition_value', 'hour_partition_value' ])

#day_partition_key = "partition_0"
#hour_partition_key = "partition_1"
#day_partition_value = "2017-08-01"
#hour_partition_value = "0"

day_partition_key = args['day_partition_key']
hour_partition_key = args['hour_partition_key']
day_partition_value = args['day_partition_value']
hour_partition_value = args['hour_partition_value']

print("Running for " + day_partition_value + "/" + hour_partition_value)

sc = SparkContext()
glueContext = GlueContext(sc)
spark = glueContext.spark_session
job = Job(glueContext)
job.init(args['JOB_NAME'], args)

df = spark.read.option("delimiter","|").csv("s3://nuviad-temp/events/"+day_partition_value+"/"+hour_partition_value)
df.registerTempTable("data")

df1 = spark.sql("select _c0 as user_id, _c1 as campaign_id, _c2 as os, _c3 as ua, cast(_c4 as bigint) as ts, cast(_c5 as double) as billing from data")

df1.repartition(1).write.mode("overwrite").parquet("s3://nuviad-temp/parquet/"+day_partition_value+"/hour="+hour_partition_value)

client = boto3.client('athena', region_name='us-east-1')

response = client.start_query_execution(
    QueryString='alter table parquet_events add if not exists partition(' + day_partition_key + '=\'' + day_partition_value + '\',' + hour_partition_key + '=' + hour_partition_value + ')  location \'s3://nuviad-temp/parquet/' + day_partition_value + '/hour=' + hour_partition_value + '\'' ,
    QueryExecutionContext={
        'Database': 'spectrumdb'
    },
    ResultConfiguration={
        'OutputLocation': 's3://nuviad-temp/convertresults'
    }
)

response = client.start_query_execution(
    QueryString='alter table parquet_events partition(' + day_partition_key + '=\'' + day_partition_value + '\',' + hour_partition_key + '=' + hour_partition_value + ') set location \'s3://nuviad-temp/parquet/' + day_partition_value + '/hour=' + hour_partition_value + '\'' ,
    QueryExecutionContext={
        'Database': 'spectrumdb'
    },
    ResultConfiguration={
        'OutputLocation': 's3://nuviad-temp/convertresults'
    }
)

job.commit()

Note: Because Redshift Spectrum and Athena both use the AWS Glue Data Catalog, we could use the Athena client to add the partition to the table.

Here are a few words about float, decimal, and double. Using decimal proved to be more challenging than we expected, as it seems that Redshift Spectrum and Spark use them differently. Whenever we used decimal in Redshift Spectrum and in Spark, we kept getting errors, such as:

S3 Query Exception (Fetch). Task failed due to an internal error. File 'https://s3-external-1.amazonaws.com/nuviad-temp/events/2017-08-01/hour=2/part-00017-48ae5b6b-906e-4875-8cde-bc36c0c6d0ca.c000.snappy.parquet has an incompatible Parquet schema for column 's3://nuviad-events/events.lat'. Column type: DECIMAL(18, 8), Parquet schema:\noptional float lat [i:4 d:1 r:0]\n (https://s3-external-1.amazonaws.com/nuviad-temp/events/2017-08-01/hour=2/part-00017-48ae5b6b-906e-4875-8cde-bc36c0c6d0ca.c000.snappy.parq

We had to experiment with a few floating-point formats until we found that the only combination that worked was to define the column as double in the Spark code and float in Spectrum. This is the reason you see billing defined as float in Spectrum and double in the Spark code.

Creating a Lambda function to trigger conversion

Next, we created a simple Lambda function to trigger the AWS Glue script hourly using a simple Python code:

import boto3
import json
from datetime import datetime, timedelta
 
client = boto3.client('glue')
 
def lambda_handler(event, context):
    last_hour_date_time = datetime.now() - timedelta(hours = 1)
    day_partition_value = last_hour_date_time.strftime("%Y-%m-%d") 
    hour_partition_value = last_hour_date_time.strftime("%-H") 
    response = client.start_job_run(
    JobName='convertEventsParquetHourly',
    Arguments={
         '--day_partition_key': 'date',
         '--hour_partition_key': 'hour',
         '--day_partition_value': day_partition_value,
         '--hour_partition_value': hour_partition_value
         }
    )

Using Amazon CloudWatch Events, we trigger this function hourly. This function triggers an AWS Glue job named ‘convertEventsParquetHourly’ and runs it for the previous hour, passing job names and values of the partitions to process to AWS Glue.

Redshift Spectrum and Node.js

Our development stack is based on Node.js, which is well-suited for high-speed, light servers that need to process a huge number of transactions. However, a few limitations of the Node.js environment required us to create workarounds and use other tools to complete the process.

Node.js and Parquet

The lack of Parquet modules for Node.js required us to implement an AWS Glue/Amazon EMR process to effectively migrate data from CSV to Parquet. We would rather save directly to Parquet, but we couldn’t find an effective way to do it.

One interesting project in the works is the development of a Parquet NPM by Marc Vertes called node-parquet (https://www.npmjs.com/package/node-parquet). It is not in a production state yet, but we think it would be well worth following the progress of this package.

Timestamp data type

According to the Parquet documentation, Timestamp data are stored in Parquet as 64-bit integers. However, JavaScript does not support 64-bit integers, because the native number type is a 64-bit double, giving only 53 bits of integer range.

The result is that you cannot store Timestamp correctly in Parquet using Node.js. The solution is to store Timestamp as string and cast the type to Timestamp in the query. Using this method, we did not witness any performance degradation whatsoever.

Lessons learned

You can benefit from our trial-and-error experience.

Lesson #1: Data validation is critical

As mentioned earlier, a single corrupt entry in a partition can fail queries running against this partition, especially when using Parquet, which is harder to edit than a simple CSV file. Make sure that you validate your data before scanning it with Redshift Spectrum.

Lesson #2: Structure and partition data effectively

One of the biggest benefits of using Redshift Spectrum (or Athena for that matter) is that you don’t need to keep nodes up and running all the time. You pay only for the queries you perform and only for the data scanned per query.

Keeping different permutations of your data for different queries makes a lot of sense in this case. For example, you can partition your data by date and hour to run time-based queries, and also have another set partitioned by user_id and date to run user-based queries. This results in faster and more efficient performance of your data warehouse.

Storing data in the right format

Use Parquet whenever you can. The benefits of Parquet are substantial. Faster performance, less data to scan, and much more efficient columnar format. However, it is not supported out-of-the-box by Kinesis Firehose, so you need to implement your own ETL. AWS Glue is a great option.

Creating small tables for frequent tasks

When we started using Redshift Spectrum, we saw our Amazon Redshift costs jump by hundreds of dollars per day. Then we realized that we were unnecessarily scanning a full day’s worth of data every minute. Take advantage of the ability to define multiple tables on the same S3 bucket or folder, and create temporary and small tables for frequent queries.

Lesson #3: Combine Athena and Redshift Spectrum for optimal performance

Moving to Redshift Spectrum also allowed us to take advantage of Athena as both use the AWS Glue Data Catalog. Run fast and simple queries using Athena while taking advantage of the advanced Amazon Redshift query engine for complex queries using Redshift Spectrum.

Redshift Spectrum excels when running complex queries. It can push many compute-intensive tasks, such as predicate filtering and aggregation, down to the Redshift Spectrum layer, so that queries use much less of your cluster’s processing capacity.

Lesson #4: Sort your Parquet data within the partition

We achieved another performance improvement by sorting data within the partition using sortWithinPartitions(sort_field). For example:

df.repartition(1).sortWithinPartitions("campaign_id")…

Conclusion

We were extremely pleased with using Amazon Redshift as our core data warehouse for over three years. But as our client base and volume of data grew substantially, we extended Amazon Redshift to take advantage of scalability, performance, and cost with Redshift Spectrum.

Redshift Spectrum lets us scale to virtually unlimited storage, scale compute transparently, and deliver super-fast results for our users. With Redshift Spectrum, we store data where we want at the cost we want, and have the data available for analytics when our users need it with the performance they expect.


About the Author

With 7 years of experience in the AdTech industry and 15 years in leading technology companies, Rafi Ton is the founder and CEO of NUVIAD. He enjoys exploring new technologies and putting them to use in cutting edge products and services, in the real world generating real money. Being an experienced entrepreneur, Rafi believes in practical-programming and fast adaptation of new technologies to achieve a significant market advantage.

 

 

Presenting Amazon Sumerian: An easy way to create VR, AR, and 3D experiences

Post Syndicated from Tara Walker original https://aws.amazon.com/blogs/aws/launch-presenting-amazon-sumerian/

If you have had an opportunity to read any of my blog posts or attended any session I’ve conducted at various conferences, you are probably aware that I am definitively a geek girl. I am absolutely enamored with all of the latest advancements that have been made in technology areas like cloud, artificial intelligence, internet of things and the maker space, as well as, with virtual reality and augmented reality. In my opinion, it is a wonderful time to be a geek. All the things that we dreamed about building while we sweated through our algorithms and discrete mathematics classes or the technology we marveled at when watching Star Wars and Star Trek are now coming to fruition.  So hopefully this means it will only be a matter of time before I can hyperdrive to other galaxies in space, but until then I can at least build the 3D virtual reality and augmented reality characters and images like those featured in some of my favorite shows.

Amazon Sumerian provides tools and resources that allows anyone to create and run augmented reality (AR), virtual reality (VR), and 3D applications with ease.  With Sumerian, you can build multi-platform experiences that run on hardware like the Oculus, HTC Vive, and iOS devices using WebVR compatible browsers and with support for ARCore on Android devices coming soon.

This exciting new service, currently in preview, delivers features to allow you to design highly immersive and interactive 3D experiences from your browser. Some of these features are:

  • Editor: A web-based editor for constructing 3D scenes, importing assets, scripting interactions and special effects, with cross-platform publishing.
  • Object Library: a library of pre-built objects and templates.
  • Asset Import: Upload 3D assets to use in your scene. Sumerian supports importing FBX, OBJ, and coming soon Unity projects.
  • Scripting Library: provides a JavaScript scripting library via its 3D engine for advanced scripting capabilities.
  • Hosts: animated, lifelike 3D characters that can be customized for gender, voice, and language.
  • AWS Services Integration: baked in integration with Amazon Polly and Amazon Lex to add speech and natural language to into Sumerian hosts. Additionally, the scripting library can be used with AWS Lambda allowing use of the full range of AWS services.

Since Amazon Sumerian doesn’t require you to have 3D graphics or programming experience to build rich, interactive VR and AR scenes, let’s take a quick run to the Sumerian Dashboard and check it out.

From the Sumerian Dashboard, I can easily create a new scene with a push of a button.

A default view of the new scene opens and is displayed in the Sumerian Editor. With the Tara Blog Scene opened in the editor, I can easily import assets into my scene.

I’ll click the Import Asset button and pick an asset, View Room, to import into the scene. With the desired asset selected, I’ll click the Add button to import it.

Excellent, my asset was successfully imported into the Sumerian Editor and is shown in the Asset panel.  Now, I have the option to add the View Room object into my scene by selecting it in the Asset panel and then dragging it onto the editor’s canvas.

I’ll repeat the import asset process and this time I will add the Mannequin asset to the scene.

Additionally, with Sumerian, I can add scripting to Entity assets to make my scene even more exciting by adding a ScriptComponent to an entity and creating a script.  I can use the provided built-in scripts or create my own custom scripts. If I create a new custom script, I will get a blank script with some base JavaScript code that looks similar to the code below.

'use strict';
/* global sumerian */
//This is Me-- trying out the custom scripts - Tara

var setup = function (args, ctx) {
// Called when play mode starts.
};
var fixedUpdate = function (args, ctx) {
// Called on every physics update, after setup().
};
var update = function (args, ctx) {
// Called on every render frame, after setup().
};
var lateUpdate = function (args, ctx) {
// Called after all script "update" methods in the scene has been called.
};
var cleanup = function (args, ctx) {
// Called when play mode stops.
};
var parameters = [];

Very cool, I just created a 3D scene using Amazon Sumerian in a matter of minutes and I have only scratched the surface.

Summary

The Amazon Sumerian service enables you to create, build, and run virtual reality (VR), augmented reality (AR), and 3D applications with ease.  You don’t need any 3D graphics or specialized programming knowledge to get started building scenes and immersive experiences.  You can import FBX, OBJ, and Unity projects in Sumerian, as well as upload your own 3D assets for use in your scene. In addition, you can create digital characters to narrate your scene and with these digital assets, you have choices for the character’s appearance, speech and behavior.

You can learn more about Amazon Sumerian and sign up for the preview to get started with the new service on the product page.  I can’t wait to see what rich experiences you all will build.

Tara

 

UI Testing at Scale with AWS Lambda

Post Syndicated from Stas Neyman original https://aws.amazon.com/blogs/devops/ui-testing-at-scale-with-aws-lambda/

This is a guest blog post by Wes Couch and Kurt Waechter from the Blackboard Internal Product Development team about their experience using AWS Lambda.

One year ago, one of our UI test suites took hours to run. Last month, it took 16 minutes. Today, it takes 39 seconds. Here’s how we did it.

The backstory:

Blackboard is a global leader in delivering robust and innovative education software and services to clients in higher education, government, K12, and corporate training. We have a large product development team working across the globe in at least 10 different time zones, with an internal tools team providing support for quality and workflows. We have been using Selenium Webdriver to perform automated cross-browser UI testing since 2007. Because we are now practicing continuous delivery, the automated UI testing challenge has grown due to the faster release schedule. On top of that, every commit made to each branch triggers an execution of our automated UI test suite. If you have ever implemented an automated UI testing infrastructure, you know that it can be very challenging to scale and maintain. Although there are services that are useful for testing different browser/OS combinations, they don’t meet our scale needs.

It used to take three hours to synchronously run our functional UI suite, which revealed the obvious need for parallel execution. Previously, we used Mesos to orchestrate a Selenium Grid Docker container for each test run. This way, we were able to run eight concurrent threads for test execution, which took an average of 16 minutes. Although this setup is fine for a single workflow, the cracks started to show when we reached the scale required for Blackboard’s mature product lines. Going beyond eight concurrent sessions on a single container introduced performance problems that impact the reliability of tests (for example, issues in Webdriver or the browser popping up frequently). We tried Mesos and considered Kubernetes for Selenium Grid orchestration, but the answer to scaling a Selenium Grid was to think smaller, not larger. This led to our breakthrough with AWS Lambda.

The solution:

We started using AWS Lambda for UI testing because it doesn’t require costly infrastructure or countless man hours to maintain. The steps we outline in this blog post took one work day, from inception to implementation. By simply packaging the UI test suite into a Lambda function, we can execute these tests in parallel on a massive scale. We use a custom JUnit test runner that invokes the Lambda function with a request to run each test from the suite. The runner then aggregates the results returned from each Lambda test execution.

Selenium is the industry standard for testing UI at scale. Although there are other options to achieve the same thing in Lambda, we chose this mature suite of tools. Selenium is backed by Google, Firefox, and others to help the industry drive their browsers with code. This makes Lambda and Selenium a compelling stack for achieving UI testing at scale.

Making Chrome Run in Lambda

Currently, Chrome for Linux will not run in Lambda due to an absent mount point. By rebuilding Chrome with a slight modification, as Marco Lüthy originally demonstrated, you can run it inside Lambda anyway! It took about two hours to build the current master branch of Chromium to build on a c4.4xlarge. Unfortunately, the current version of ChromeDriver, 2.33, does not support any version of Chrome above 62, so we’ll be using Marco’s modified version of version 60 for the near future.

Required System Libraries

The Lambda runtime environment comes with a subset of common shared libraries. This means we need to include some extra libraries to get Chrome and ChromeDriver to work. Anything that exists in the java resources folder during compile time is included in the base directory of the compiled jar file. When this jar file is deployed to Lambda, it is placed in the /var/task/ directory. This allows us to simply place the libraries in the java resources folder under a folder named lib/ so they are right where they need to be when the Lambda function is invoked.

To get these libraries, create an EC2 instance and choose the Amazon Linux AMI.

Next, use ssh to connect to the server. After you connect to the new instance, search for the libraries to find their locations.

sudo find / -name libgconf-2.so.4
sudo find / -name libORBit-2.so.0

Now that you have the locations of the libraries, copy these files from the EC2 instance and place them in the java resources folder under lib/.

Packaging the Tests

To deploy the test suite to Lambda, we used a simple Gradle tool called ShadowJar, which is similar to the Maven Shade Plugin. It packages the libraries and dependencies inside the jar that is built. Usually test dependencies and sources aren’t included in a jar, but for this instance we want to include them. To include the test dependencies, add this section to the build.gradle file.

shadowJar {
   from sourceSets.test.output
   configurations = [project.configurations.testRuntime]
}

Deploying the Test Suite

Now that our tests are packaged with the dependencies in a jar, we need to get them into a running Lambda function. We use  simple SAM  templates to upload the packaged jar into S3, and then deploy it to Lambda with our settings.

{
   "AWSTemplateFormatVersion": "2010-09-09",
   "Transform": "AWS::Serverless-2016-10-31",
   "Resources": {
       "LambdaTestHandler": {
           "Type": "AWS::Serverless::Function",
           "Properties": {
               "CodeUri": "./build/libs/your-test-jar-all.jar",
               "Runtime": "java8",
               "Handler": "com.example.LambdaTestHandler::handleRequest",
               "Role": "<YourLambdaRoleArn>",
               "Timeout": 300,
               "MemorySize": 1536
           }
       }
   }
}

We use the maximum timeout available to ensure our tests have plenty of time to run. We also use the maximum memory size because this ensures our Lambda function can support Chrome and other resources required to run a UI test.

Specifying the handler is important because this class executes the desired test. The test handler should be able to receive a test class and method. With this information it will then execute the test and respond with the results.

public LambdaTestResult handleRequest(TestRequest testRequest, Context context) {
   LoggerContainer.LOGGER = new Logger(context.getLogger());
  
   BlockJUnit4ClassRunner runner = getRunnerForSingleTest(testRequest);
  
   Result result = new JUnitCore().run(runner);

   return new LambdaTestResult(result);
}

Creating a Lambda-Compatible ChromeDriver

We provide developers with an easily accessible ChromeDriver for local test writing and debugging. When we are running tests on AWS, we have configured ChromeDriver to run them in Lambda.

To configure ChromeDriver, we first need to tell ChromeDriver where to find the Chrome binary. Because we know that ChromeDriver is going to be unzipped into the root task directory, we should point the ChromeDriver configuration at that location.

The settings for getting ChromeDriver running are mostly related to Chrome, which must have its working directories pointed at the tmp/ folder.

Start with the default DesiredCapabilities for ChromeDriver, and then add the following settings to enable your ChromeDriver to start in Lambda.

public ChromeDriver createLambdaChromeDriver() {
   ChromeOptions options = new ChromeOptions();

   // Set the location of the chrome binary from the resources folder
   options.setBinary("/var/task/chrome");

   // Include these settings to allow Chrome to run in Lambda
   options.addArguments("--disable-gpu");
   options.addArguments("--headless");
   options.addArguments("--window-size=1366,768");
   options.addArguments("--single-process");
   options.addArguments("--no-sandbox");
   options.addArguments("--user-data-dir=/tmp/user-data");
   options.addArguments("--data-path=/tmp/data-path");
   options.addArguments("--homedir=/tmp");
   options.addArguments("--disk-cache-dir=/tmp/cache-dir");
  
   DesiredCapabilities desiredCapabilities = DesiredCapabilities.chrome();
   desiredCapabilities.setCapability(ChromeOptions.CAPABILITY, options);
  
   return new ChromeDriver(desiredCapabilities);
}

Executing Tests in Parallel

You can approach parallel test execution in Lambda in many different ways. Your approach depends on the structure and design of your test suite. For our solution, we implemented a custom test runner that uses reflection and JUnit libraries to create a list of test cases we want run. When we have the list, we create a TestRequest object to pass into the Lambda function that we have deployed. In this TestRequest, we place the class name, test method, and the test run identifier. When the Lambda function receives this TestRequest, our LambdaTestHandler generates and runs the JUnit test. After the test is complete, the test result is sent to the test runner. The test runner compiles a result after all of the tests are complete. By executing the same Lambda function multiple times with different test requests, we can effectively run the entire test suite in parallel.

To get screenshots and other test data, we pipe those files during test execution to an S3 bucket under the test run identifier prefix. When the tests are complete, we link the files to each test execution in the report generated from the test run. This lets us easily investigate test executions.

Pro Tip: Dynamically Loading Binaries

AWS Lambda has a limit of 250 MB of uncompressed space for packaged Lambda functions. Because we have libraries and other dependencies to our test suite, we hit this limit when we tried to upload a function that contained Chrome and ChromeDriver (~140 MB). This test suite was not originally intended to be used with Lambda. Otherwise, we would have scrutinized some of the included libraries. To get around this limit, we used the Lambda functions temporary directory, which allows up to 500 MB of space at runtime. Downloading these binaries at runtime moves some of that space requirement into the temporary directory. This allows more room for libraries and dependencies. You can do this by grabbing Chrome and ChromeDriver from an S3 bucket and marking them as executable using built-in Java libraries. If you take this route, be sure to point to the new location for these executables in order to create a ChromeDriver.

private static void downloadS3ObjectToExecutableFile(String key) throws IOException {
   File file = new File("/tmp/" + key);

   GetObjectRequest request = new GetObjectRequest("s3-bucket-name", key);

   FileUtils.copyInputStreamToFile(s3client.getObject(request).getObjectContent(), file);
   file.setExecutable(true);
}

Lambda-Selenium Project Source

We have compiled an open source example that you can grab from the Blackboard Github repository. Grab the code and try it out!

https://blackboard.github.io/lambda-selenium/

Conclusion

One year ago, one of our UI test suites took hours to run. Last month, it took 16 minutes. Today, it takes 39 seconds. Thanks to AWS Lambda, we can reduce our build times and perform automated UI testing at scale!

How to Patch, Inspect, and Protect Microsoft Windows Workloads on AWS—Part 2

Post Syndicated from Koen van Blijderveen original https://aws.amazon.com/blogs/security/how-to-patch-inspect-and-protect-microsoft-windows-workloads-on-aws-part-2/

Yesterday in Part 1 of this blog post, I showed you how to:

  1. Launch an Amazon EC2 instance with an AWS Identity and Access Management (IAM) role, an Amazon Elastic Block Store (Amazon EBS) volume, and tags that Amazon EC2 Systems Manager (Systems Manager) and Amazon Inspector use.
  2. Configure Systems Manager to install the Amazon Inspector agent and patch your EC2 instances.

Today in Steps 3 and 4, I show you how to:

  1. Take Amazon EBS snapshots using Amazon EBS Snapshot Scheduler to automate snapshots based on instance tags.
  2. Use Amazon Inspector to check if your EC2 instances running Microsoft Windows contain any common vulnerabilities and exposures (CVEs).

To catch up on Steps 1 and 2, see yesterday’s blog post.

Step 3: Take EBS snapshots using EBS Snapshot Scheduler

In this section, I show you how to use EBS Snapshot Scheduler to take snapshots of your instances at specific intervals. To do this, I will show you how to:

  • Determine the schedule for EBS Snapshot Scheduler by providing you with best practices.
  • Deploy EBS Snapshot Scheduler by using AWS CloudFormation.
  • Tag your EC2 instances so that EBS Snapshot Scheduler backs up your instances when you want them backed up.

In addition to making sure your EC2 instances have all the available operating system patches applied on a regular schedule, you should take snapshots of the EBS storage volumes attached to your EC2 instances. Taking regular snapshots allows you to restore your data to a previous state quickly and cost effectively. With Amazon EBS snapshots, you pay only for the actual data you store, and snapshots save only the data that has changed since the previous snapshot, which minimizes your cost. You will use EBS Snapshot Scheduler to make regular snapshots of your EC2 instance. EBS Snapshot Scheduler takes advantage of other AWS services including CloudFormation, Amazon DynamoDB, and AWS Lambda to make backing up your EBS volumes simple.

Determine the schedule

As a best practice, you should back up your data frequently during the hours when your data changes the most. This reduces the amount of data you lose if you have to restore from a snapshot. For the purposes of this blog post, the data for my instances changes the most between the business hours of 9:00 A.M. to 5:00 P.M. Pacific Time. During these hours, I will make snapshots hourly to minimize data loss.

In addition to backing up frequently, another best practice is to establish a strategy for retention. This will vary based on how you need to use the snapshots. If you have compliance requirements to be able to restore for auditing, your needs may be different than if you are able to detect data corruption within three hours and simply need to restore to something that limits data loss to five hours. EBS Snapshot Scheduler enables you to specify the retention period for your snapshots. For this post, I only need to keep snapshots for recent business days. To account for weekends, I will set my retention period to three days, which is down from the default of 15 days when deploying EBS Snapshot Scheduler.

Deploy EBS Snapshot Scheduler

In Step 1 of Part 1 of this post, I showed how to configure an EC2 for Windows Server 2012 R2 instance with an EBS volume. You will use EBS Snapshot Scheduler to take eight snapshots each weekday of your EC2 instance’s EBS volumes:

  1. Navigate to the EBS Snapshot Scheduler deployment page and choose Launch Solution. This takes you to the CloudFormation console in your account. The Specify an Amazon S3 template URL option is already selected and prefilled. Choose Next on the Select Template page.
  2. On the Specify Details page, retain all default parameters except for AutoSnapshotDeletion. Set AutoSnapshotDeletion to Yes to ensure that old snapshots are periodically deleted. The default retention period is 15 days (you will specify a shorter value on your instance in the next subsection).
  3. Choose Next twice to move to the Review step, and start deployment by choosing the I acknowledge that AWS CloudFormation might create IAM resources check box and then choosing Create.

Tag your EC2 instances

EBS Snapshot Scheduler takes a few minutes to deploy. While waiting for its deployment, you can start to tag your instance to define its schedule. EBS Snapshot Scheduler reads tag values and looks for four possible custom parameters in the following order:

  • <snapshot time> – Time in 24-hour format with no colon.
  • <retention days> – The number of days (a positive integer) to retain the snapshot before deletion, if set to automatically delete snapshots.
  • <time zone> – The time zone of the times specified in <snapshot time>.
  • <active day(s)>all, weekdays, or mon, tue, wed, thu, fri, sat, and/or sun.

Because you want hourly backups on weekdays between 9:00 A.M. and 5:00 P.M. Pacific Time, you need to configure eight tags—one for each hour of the day. You will add the eight tags shown in the following table to your EC2 instance.

Tag Value
scheduler:ebs-snapshot:0900 0900;3;utc;weekdays
scheduler:ebs-snapshot:1000 1000;3;utc;weekdays
scheduler:ebs-snapshot:1100 1100;3;utc;weekdays
scheduler:ebs-snapshot:1200 1200;3;utc;weekdays
scheduler:ebs-snapshot:1300 1300;3;utc;weekdays
scheduler:ebs-snapshot:1400 1400;3;utc;weekdays
scheduler:ebs-snapshot:1500 1500;3;utc;weekdays
scheduler:ebs-snapshot:1600 1600;3;utc;weekdays

Next, you will add these tags to your instance. If you want to tag multiple instances at once, you can use Tag Editor instead. To add the tags in the preceding table to your EC2 instance:

  1. Navigate to your EC2 instance in the EC2 console and choose Tags in the navigation pane.
  2. Choose Add/Edit Tags and then choose Create Tag to add all the tags specified in the preceding table.
  3. Confirm you have added the tags by choosing Save. After adding these tags, navigate to your EC2 instance in the EC2 console. Your EC2 instance should look similar to the following screenshot.
    Screenshot of how your EC2 instance should look in the console
  4. After waiting a couple of hours, you can see snapshots beginning to populate on the Snapshots page of the EC2 console.Screenshot of snapshots beginning to populate on the Snapshots page of the EC2 console
  5. To check if EBS Snapshot Scheduler is active, you can check the CloudWatch rule that runs the Lambda function. If the clock icon shown in the following screenshot is green, the scheduler is active. If the clock icon is gray, the rule is disabled and does not run. You can enable or disable the rule by selecting it, choosing Actions, and choosing Enable or Disable. This also allows you to temporarily disable EBS Snapshot Scheduler.Screenshot of checking to see if EBS Snapshot Scheduler is active
  1. You can also monitor when EBS Snapshot Scheduler has run by choosing the name of the CloudWatch rule as shown in the previous screenshot and choosing Show metrics for the rule.Screenshot of monitoring when EBS Snapshot Scheduler has run by choosing the name of the CloudWatch rule

If you want to restore and attach an EBS volume, see Restoring an Amazon EBS Volume from a Snapshot and Attaching an Amazon EBS Volume to an Instance.

Step 4: Use Amazon Inspector

In this section, I show you how to you use Amazon Inspector to scan your EC2 instance for common vulnerabilities and exposures (CVEs) and set up Amazon SNS notifications. To do this I will show you how to:

  • Install the Amazon Inspector agent by using EC2 Run Command.
  • Set up notifications using Amazon SNS to notify you of any findings.
  • Define an Amazon Inspector target and template to define what assessment to perform on your EC2 instance.
  • Schedule Amazon Inspector assessment runs to assess your EC2 instance on a regular interval.

Amazon Inspector can help you scan your EC2 instance using prebuilt rules packages, which are built and maintained by AWS. These prebuilt rules packages tell Amazon Inspector what to scan for on the EC2 instances you select. Amazon Inspector provides the following prebuilt packages for Microsoft Windows Server 2012 R2:

  • Common Vulnerabilities and Exposures
  • Center for Internet Security Benchmarks
  • Runtime Behavior Analysis

In this post, I’m focused on how to make sure you keep your EC2 instances patched, backed up, and inspected for common vulnerabilities and exposures (CVEs). As a result, I will focus on how to use the CVE rules package and use your instance tags to identify the instances on which to run the CVE rules. If your EC2 instance is fully patched using Systems Manager, as described earlier, you should not have any findings with the CVE rules package. Regardless, as a best practice I recommend that you use Amazon Inspector as an additional layer for identifying any unexpected failures. This involves using Amazon CloudWatch to set up weekly Amazon Inspector scans, and configuring Amazon Inspector to notify you of any findings through SNS topics. By acting on the notifications you receive, you can respond quickly to any CVEs on any of your EC2 instances to help ensure that malware using known CVEs does not affect your EC2 instances. In a previous blog post, Eric Fitzgerald showed how to remediate Amazon Inspector security findings automatically.

Install the Amazon Inspector agent

To install the Amazon Inspector agent, you will use EC2 Run Command, which allows you to run any command on any of your EC2 instances that have the Systems Manager agent with an attached IAM role that allows access to Systems Manager.

  1. Choose Run Command under Systems Manager Services in the navigation pane of the EC2 console. Then choose Run a command.
    Screenshot of choosing "Run a command"
  2. To install the Amazon Inspector agent, you will use an AWS managed and provided command document that downloads and installs the agent for you on the selected EC2 instance. Choose AmazonInspector-ManageAWSAgent. To choose the target EC2 instance where this command will be run, use the tag you previously assigned to your EC2 instance, Patch Group, with a value of Windows Servers. For this example, set the concurrent installations to 1 and tell Systems Manager to stop after 5 errors.
    Screenshot of installing the Amazon Inspector agent
  3. Retain the default values for all other settings on the Run a command page and choose Run. Back on the Run Command page, you can see if the command that installed the Amazon Inspector agent executed successfully on all selected EC2 instances.
    Screenshot showing that the command that installed the Amazon Inspector agent executed successfully on all selected EC2 instances

Set up notifications using Amazon SNS

Now that you have installed the Amazon Inspector agent, you will set up an SNS topic that will notify you of any findings after an Amazon Inspector run.

To set up an SNS topic:

  1. In the AWS Management Console, choose Simple Notification Service under Messaging in the Services menu.
  2. Choose Create topic, name your topic (only alphanumeric characters, hyphens, and underscores are allowed) and give it a display name to ensure you know what this topic does (I’ve named mine Inspector). Choose Create topic.
    "Create new topic" page
  3. To allow Amazon Inspector to publish messages to your new topic, choose Other topic actions and choose Edit topic policy.
  4. For Allow these users to publish messages to this topic and Allow these users to subscribe to this topic, choose Only these AWS users. Type the following ARN for the US East (N. Virginia) Region in which you are deploying the solution in this post: arn:aws:iam::316112463485:root. This is the ARN of Amazon Inspector itself. For the ARNs of Amazon Inspector in other AWS Regions, see Setting Up an SNS Topic for Amazon Inspector Notifications (Console). Amazon Resource Names (ARNs) uniquely identify AWS resources across all of AWS.
    Screenshot of editing the topic policy
  5. To receive notifications from Amazon Inspector, subscribe to your new topic by choosing Create subscription and adding your email address. After confirming your subscription by clicking the link in the email, the topic should display your email address as a subscriber. Later, you will configure the Amazon Inspector template to publish to this topic.
    Screenshot of subscribing to the new topic

Define an Amazon Inspector target and template

Now that you have set up the notification topic by which Amazon Inspector can notify you of findings, you can create an Amazon Inspector target and template. A target defines which EC2 instances are in scope for Amazon Inspector. A template defines which packages to run, for how long, and on which target.

To create an Amazon Inspector target:

  1. Navigate to the Amazon Inspector console and choose Get started. At the time of writing this blog post, Amazon Inspector is available in the US East (N. Virginia), US West (N. California), US West (Oregon), EU (Ireland), Asia Pacific (Mumbai), Asia Pacific (Seoul), Asia Pacific (Sydney), and Asia Pacific (Tokyo) Regions.
  2. For Amazon Inspector to be able to collect the necessary data from your EC2 instance, you must create an IAM service role for Amazon Inspector. Amazon Inspector can create this role for you if you choose Choose or create role and confirm the role creation by choosing Allow.
    Screenshot of creating an IAM service role for Amazon Inspector
  3. Amazon Inspector also asks you to tag your EC2 instance and install the Amazon Inspector agent. You already performed these steps in Part 1 of this post, so you can proceed by choosing Next. To define the Amazon Inspector target, choose the previously used Patch Group tag with a Value of Windows Servers. This is the same tag that you used to define the targets for patching. Then choose Next.
    Screenshot of defining the Amazon Inspector target
  4. Now, define your Amazon Inspector template, and choose a name and the package you want to run. For this post, use the Common Vulnerabilities and Exposures package and choose the default duration of 1 hour. As you can see, the package has a version number, so always select the latest version of the rules package if multiple versions are available.
    Screenshot of defining an assessment template
  5. Configure Amazon Inspector to publish to your SNS topic when findings are reported. You can also choose to receive a notification of a started run, a finished run, or changes in the state of a run. For this blog post, you want to receive notifications if there are any findings. To start, choose Assessment Templates from the Amazon Inspector console and choose your newly created Amazon Inspector assessment template. Choose the icon below SNS topics (see the following screenshot).
    Screenshot of choosing an assessment template
  6. A pop-up appears in which you can choose the previously created topic and the events about which you want SNS to notify you (choose Finding reported).
    Screenshot of choosing the previously created topic and the events about which you want SNS to notify you

Schedule Amazon Inspector assessment runs

The last step in using Amazon Inspector to assess for CVEs is to schedule the Amazon Inspector template to run using Amazon CloudWatch Events. This will make sure that Amazon Inspector assesses your EC2 instance on a regular basis. To do this, you need the Amazon Inspector template ARN, which you can find under Assessment templates in the Amazon Inspector console. CloudWatch Events can run your Amazon Inspector assessment at an interval you define using a Cron-based schedule. Cron is a well-known scheduling agent that is widely used on UNIX-like operating systems and uses the following syntax for CloudWatch Events.

Image of Cron schedule

All scheduled events use a UTC time zone, and the minimum precision for schedules is one minute. For more information about scheduling CloudWatch Events, see Schedule Expressions for Rules.

To create the CloudWatch Events rule:

  1. Navigate to the CloudWatch console, choose Events, and choose Create rule.
    Screenshot of starting to create a rule in the CloudWatch Events console
  2. On the next page, specify if you want to invoke your rule based on an event pattern or a schedule. For this blog post, you will select a schedule based on a Cron expression.
  3. You can schedule the Amazon Inspector assessment any time you want using the Cron expression, or you can use the Cron expression I used in the following screenshot, which will run the Amazon Inspector assessment every Sunday at 10:00 P.M. GMT.
    Screenshot of scheduling an Amazon Inspector assessment with a Cron expression
  4. Choose Add target and choose Inspector assessment template from the drop-down menu. Paste the ARN of the Amazon Inspector template you previously created in the Amazon Inspector console in the Assessment template box and choose Create a new role for this specific resource. This new role is necessary so that CloudWatch Events has the necessary permissions to start the Amazon Inspector assessment. CloudWatch Events will automatically create the new role and grant the minimum set of permissions needed to run the Amazon Inspector assessment. To proceed, choose Configure details.
    Screenshot of adding a target
  5. Next, give your rule a name and a description. I suggest using a name that describes what the rule does, as shown in the following screenshot.
  6. Finish the wizard by choosing Create rule. The rule should appear in the Events – Rules section of the CloudWatch console.
    Screenshot of completing the creation of the rule
  7. To confirm your CloudWatch Events rule works, wait for the next time your CloudWatch Events rule is scheduled to run. For testing purposes, you can choose your CloudWatch Events rule and choose Edit to change the schedule to run it sooner than scheduled.
    Screenshot of confirming the CloudWatch Events rule works
  8. Now navigate to the Amazon Inspector console to confirm the launch of your first assessment run. The Start time column shows you the time each assessment started and the Status column the status of your assessment. In the following screenshot, you can see Amazon Inspector is busy Collecting data from the selected assessment targets.
    Screenshot of confirming the launch of the first assessment run

You have concluded the last step of this blog post by setting up a regular scan of your EC2 instance with Amazon Inspector and a notification that will let you know if your EC2 instance is vulnerable to any known CVEs. In a previous Security Blog post, Eric Fitzgerald explained How to Remediate Amazon Inspector Security Findings Automatically. Although that blog post is for Linux-based EC2 instances, the post shows that you can learn about Amazon Inspector findings in other ways than email alerts.

Conclusion

In this two-part blog post, I showed how to make sure you keep your EC2 instances up to date with patching, how to back up your instances with snapshots, and how to monitor your instances for CVEs. Collectively these measures help to protect your instances against common attack vectors that attempt to exploit known vulnerabilities. In Part 1, I showed how to configure your EC2 instances to make it easy to use Systems Manager, EBS Snapshot Scheduler, and Amazon Inspector. I also showed how to use Systems Manager to schedule automatic patches to keep your instances current in a timely fashion. In Part 2, I showed you how to take regular snapshots of your data by using EBS Snapshot Scheduler and how to use Amazon Inspector to check if your EC2 instances running Microsoft Windows contain any common vulnerabilities and exposures (CVEs).

If you have comments about today’s or yesterday’s post, submit them in the “Comments” section below. If you have questions about or issues implementing any part of this solution, start a new thread on the Amazon EC2 forum or the Amazon Inspector forum, or contact AWS Support.

– Koen