Tag Archives: Dyn

Get Started with Blockchain Using the new AWS Blockchain Templates

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/get-started-with-blockchain-using-the-new-aws-blockchain-templates/

Many of today’s discussions around blockchain technology remind me of the classic Shimmer Floor Wax skit. According to Dan Aykroyd, Shimmer is a dessert topping. Gilda Radner claims that it is a floor wax, and Chevy Chase settles the debate and reveals that it actually is both! Some of the people that I talk to see blockchains as the foundation of a new monetary system and a way to facilitate international payments. Others see blockchains as a distributed ledger and immutable data source that can be applied to logistics, supply chain, land registration, crowdfunding, and other use cases. Either way, it is clear that there are a lot of intriguing possibilities and we are working to help our customers use this technology more effectively.

We are launching AWS Blockchain Templates today. These templates will let you launch an Ethereum (either public or private) or Hyperledger Fabric (private) network in a matter of minutes and with just a few clicks. The templates create and configure all of the AWS resources needed to get you going in a robust and scalable fashion.

Launching a Private Ethereum Network
The Ethereum template offers two launch options. The ecs option creates an Amazon ECS cluster within a Virtual Private Cloud (VPC) and launches a set of Docker images in the cluster. The docker-local option also runs within a VPC, and launches the Docker images on EC2 instances. The template supports Ethereum mining, the EthStats and EthExplorer status pages, and a set of nodes that implement and respond to the Ethereum RPC protocol. Both options create and make use of a DynamoDB table for service discovery, along with Application Load Balancers for the status pages.

Here are the AWS Blockchain Templates for Ethereum:

I start by opening the CloudFormation Console in the desired region and clicking Create Stack:

I select Specify an Amazon S3 template URL, enter the URL of the template for the region, and click Next:

I give my stack a name:

Next, I enter the first set of parameters, including the network ID for the genesis block. I’ll stick with the default values for now:

I will also use the default values for the remaining network parameters:

Moving right along, I choose the container orchestration platform (ecs or docker-local, as I explained earlier) and the EC2 instance type for the container nodes:

Next, I choose my VPC and the subnets for the Ethereum network and the Application Load Balancer:

I configure my keypair, EC2 security group, IAM role, and instance profile ARN (full information on the required permissions can be found in the documentation):

The Instance Profile ARN can be found on the summary page for the role:

I confirm that I want to deploy EthStats and EthExplorer, choose the tag and version for the nested CloudFormation templates that are used by this one, and click Next to proceed:

On the next page I specify a tag for the resources that the stack will create, leave the other options as-is, and click Next:

I review all of the parameters and options, acknowledge that the stack might create IAM resources, and click Create to build my network:

The template makes use of three nested templates:

After all of the stacks have been created (mine took about 5 minutes), I can select JeffNet and click the Outputs tab to discover the links to EthStats and EthExplorer:

Here’s my EthStats:

And my EthExplorer:

If I am writing apps that make use of my private network to store and process smart contracts, I would use the EthJsonRpcUrl.

Stay Tuned
My colleagues are eager to get your feedback on these new templates and plan to add new versions of the frameworks as they become available.

Jeff;

 

AWS AppSync – Production-Ready with Six New Features

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/aws-appsync-production-ready-with-six-new-features/

If you build (or want to build) data-driven web and mobile apps and need real-time updates and the ability to work offline, you should take a look at AWS AppSync. Announced in preview form at AWS re:Invent 2017 and described in depth here, AWS AppSync is designed for use in iOS, Android, JavaScript, and React Native apps. AWS AppSync is built around GraphQL, an open, standardized query language that makes it easy for your applications to request the precise data that they need from the cloud.

I’m happy to announce that the preview period is over and that AWS AppSync is now generally available and production-ready, with six new features that will simplify and streamline your application development process:

Console Log Access – You can now see the CloudWatch Logs entries that are created when you test your GraphQL queries, mutations, and subscriptions from within the AWS AppSync Console.

Console Testing with Mock Data – You can now create and use mock context objects in the console for testing purposes.

Subscription Resolvers – You can now create resolvers for AWS AppSync subscription requests, just as you can already do for query and mutate requests.

Batch GraphQL Operations for DynamoDB – You can now make use of DynamoDB’s batch operations (BatchGetItem and BatchWriteItem) across one or more tables. in your resolver functions.

CloudWatch Support – You can now use Amazon CloudWatch Metrics and CloudWatch Logs to monitor calls to the AWS AppSync APIs.

CloudFormation Support – You can now define your schemas, data sources, and resolvers using AWS CloudFormation templates.

A Brief AppSync Review
Before diving in to the new features, let’s review the process of creating an AWS AppSync API, starting from the console. I click Create API to begin:

I enter a name for my API and (for demo purposes) choose to use the Sample schema:

The schema defines a collection of GraphQL object types. Each object type has a set of fields, with optional arguments:

If I was creating an API of my own I would enter my schema at this point. Since I am using the sample, I don’t need to do this. Either way, I click on Create to proceed:

The GraphQL schema type defines the entry points for the operations on the data. All of the data stored on behalf of a particular schema must be accessible using a path that begins at one of these entry points. The console provides me with an endpoint and key for my API:

It also provides me with guidance and a set of fully functional sample apps that I can clone:

When I clicked Create, AWS AppSync created a pair of Amazon DynamoDB tables for me. I can click Data Sources to see them:

I can also see and modify my schema, issue queries, and modify an assortment of settings for my API.

Let’s take a quick look at each new feature…

Console Log Access
The AWS AppSync Console already allows me to issue queries and to see the results, and now provides access to relevant log entries.In order to see the entries, I must enable logs (as detailed below), open up the LOGS, and check the checkbox. Here’s a simple mutation query that adds a new event. I enter the query and click the arrow to test it:

I can click VIEW IN CLOUDWATCH for a more detailed view:

To learn more, read Test and Debug Resolvers.

Console Testing with Mock Data
You can now create a context object in the console where it will be passed to one of your resolvers for testing purposes. I’ll add a testResolver item to my schema:

Then I locate it on the right-hand side of the Schema page and click Attach:

I choose a data source (this is for testing and the actual source will not be accessed), and use the Put item mapping template:

Then I click Select test context, choose Create New Context, assign a name to my test content, and click Save (as you can see, the test context contains the arguments from the query along with values to be returned for each field of the result):

After I save the new Resolver, I click Test to see the request and the response:

Subscription Resolvers
Your AWS AppSync application can monitor changes to any data source using the @aws_subscribe GraphQL schema directive and defining a Subscription type. The AWS AppSync client SDK connects to AWS AppSync using MQTT over Websockets and the application is notified after each mutation. You can now attach resolvers (which convert GraphQL payloads into the protocol needed by the underlying storage system) to your subscription fields and perform authorization checks when clients attempt to connect. This allows you to perform the same fine grained authorization routines across queries, mutations, and subscriptions.

To learn more about this feature, read Real-Time Data.

Batch GraphQL Operations
Your resolvers can now make use of DynamoDB batch operations that span one or more tables in a region. This allows you to use a list of keys in a single query, read records multiple tables, write records in bulk to multiple tables, and conditionally write or delete related records across multiple tables.

In order to use this feature the IAM role that you use to access your tables must grant access to DynamoDB’s BatchGetItem and BatchPutItem functions.

To learn more, read the DynamoDB Batch Resolvers tutorial.

CloudWatch Logs Support
You can now tell AWS AppSync to log API requests to CloudWatch Logs. Click on Settings and Enable logs, then choose the IAM role and the log level:

CloudFormation Support
You can use the following CloudFormation resource types in your templates to define AWS AppSync resources:

AWS::AppSync::GraphQLApi – Defines an AppSync API in terms of a data source (an Amazon Elasticsearch Service domain or a DynamoDB table).

AWS::AppSync::ApiKey – Defines the access key needed to access the data source.

AWS::AppSync::GraphQLSchema – Defines a GraphQL schema.

AWS::AppSync::DataSource – Defines a data source.

AWS::AppSync::Resolver – Defines a resolver by referencing a schema and a data source, and includes a mapping template for requests.

Here’s a simple schema definition in YAML form:

  AppSyncSchema:
    Type: "AWS::AppSync::GraphQLSchema"
    DependsOn:
      - AppSyncGraphQLApi
    Properties:
      ApiId: !GetAtt AppSyncGraphQLApi.ApiId
      Definition: |
        schema {
          query: Query
          mutation: Mutation
        }
        type Query {
          singlePost(id: ID!): Post
          allPosts: [Post]
        }
        type Mutation {
          putPost(id: ID!, title: String!): Post
        }
        type Post {
          id: ID!
          title: String!
        }

Available Now
These new features are available now and you can start using them today! Here are a couple of blog posts and other resources that you might find to be of interest:

Jeff;

 

 

COPPA Compliance

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2018/04/coppa_complianc.html

Interesting research: “‘Won’t Somebody Think of the Children?’ Examining COPPA Compliance at Scale“:

Abstract: We present a scalable dynamic analysis framework that allows for the automatic evaluation of the privacy behaviors of Android apps. We use our system to analyze mobile apps’ compliance with the Children’s Online Privacy Protection Act (COPPA), one of the few stringent privacy laws in the U.S. Based on our automated analysis of 5,855 of the most popular free children’s apps, we found that a majority are potentially in violation of COPPA, mainly due to their use of third-party SDKs. While many of these SDKs offer configuration options to respect COPPA by disabling tracking and behavioral advertising, our data suggest that a majority of apps either do not make use of these options or incorrectly propagate them across mediation SDKs. Worse, we observed that 19% of children’s apps collect identifiers or other personally identifiable information (PII) via SDKs whose terms of service outright prohibit their use in child-directed apps. Finally, we show that efforts by Google to limit tracking through the use of a resettable advertising ID have had little success: of the 3,454 apps that share the resettable ID with advertisers, 66% transmit other, non-resettable, persistent identifiers as well, negating any intended privacy-preserving properties of the advertising ID.

How to retain system tables’ data spanning multiple Amazon Redshift clusters and run cross-cluster diagnostic queries

Post Syndicated from Karthik Sonti original https://aws.amazon.com/blogs/big-data/how-to-retain-system-tables-data-spanning-multiple-amazon-redshift-clusters-and-run-cross-cluster-diagnostic-queries/

Amazon Redshift is a data warehouse service that logs the history of the system in STL log tables. The STL log tables manage disk space by retaining only two to five days of log history, depending on log usage and available disk space.

To retain STL tables’ data for an extended period, you usually have to create a replica table for every system table. Then, for each you load the data from the system table into the replica at regular intervals. By maintaining replica tables for STL tables, you can run diagnostic queries on historical data from the STL tables. You then can derive insights from query execution times, query plans, and disk-spill patterns, and make better cluster-sizing decisions. However, refreshing replica tables with live data from STL tables at regular intervals requires schedulers such as Cron or AWS Data Pipeline. Also, these tables are specific to one cluster and they are not accessible after the cluster is terminated. This is especially true for transient Amazon Redshift clusters that last for only a finite period of ad hoc query execution.

In this blog post, I present a solution that exports system tables from multiple Amazon Redshift clusters into an Amazon S3 bucket. This solution is serverless, and you can schedule it as frequently as every five minutes. The AWS CloudFormation deployment template that I provide automates the solution setup in your environment. The system tables’ data in the Amazon S3 bucket is partitioned by cluster name and query execution date to enable efficient joins in cross-cluster diagnostic queries.

I also provide another CloudFormation template later in this post. This second template helps to automate the creation of tables in the AWS Glue Data Catalog for the system tables’ data stored in Amazon S3. After the system tables are exported to Amazon S3, you can run cross-cluster diagnostic queries on the system tables’ data and derive insights about query executions in each Amazon Redshift cluster. You can do this using Amazon QuickSight, Amazon Athena, Amazon EMR, or Amazon Redshift Spectrum.

You can find all the code examples in this post, including the CloudFormation templates, AWS Glue extract, transform, and load (ETL) scripts, and the resolution steps for common errors you might encounter in this GitHub repository.

Solution overview

The solution in this post uses AWS Glue to export system tables’ log data from Amazon Redshift clusters into Amazon S3. The AWS Glue ETL jobs are invoked at a scheduled interval by AWS Lambda. AWS Systems Manager, which provides secure, hierarchical storage for configuration data management and secrets management, maintains the details of Amazon Redshift clusters for which the solution is enabled. The last-fetched time stamp values for the respective cluster-table combination are maintained in an Amazon DynamoDB table.

The following diagram covers the key steps involved in this solution.

The solution as illustrated in the preceding diagram flows like this:

  1. The Lambda function, invoke_rs_stl_export_etl, is triggered at regular intervals, as controlled by Amazon CloudWatch. It’s triggered to look up the AWS Systems Manager parameter store to get the details of the Amazon Redshift clusters for which the system table export is enabled.
  2. The same Lambda function, based on the Amazon Redshift cluster details obtained in step 1, invokes the AWS Glue ETL job designated for the Amazon Redshift cluster. If an ETL job for the cluster is not found, the Lambda function creates one.
  3. The ETL job invoked for the Amazon Redshift cluster gets the cluster credentials from the parameter store. It gets from the DynamoDB table the last exported time stamp of when each of the system tables was exported from the respective Amazon Redshift cluster.
  4. The ETL job unloads the system tables’ data from the Amazon Redshift cluster into an Amazon S3 bucket.
  5. The ETL job updates the DynamoDB table with the last exported time stamp value for each system table exported from the Amazon Redshift cluster.
  6. The Amazon Redshift cluster system tables’ data is available in Amazon S3 and is partitioned by cluster name and date for running cross-cluster diagnostic queries.

Understanding the configuration data

This solution uses AWS Systems Manager parameter store to store the Amazon Redshift cluster credentials securely. The parameter store also securely stores other configuration information that the AWS Glue ETL job needs for extracting and storing system tables’ data in Amazon S3. Systems Manager comes with a default AWS Key Management Service (AWS KMS) key that it uses to encrypt the password component of the Amazon Redshift cluster credentials.

The following table explains the global parameters and cluster-specific parameters required in this solution. The global parameters are defined once and applicable at the overall solution level. The cluster-specific parameters are specific to an Amazon Redshift cluster and repeat for each cluster for which you enable this post’s solution. The CloudFormation template explained later in this post creates these parameters as part of the deployment process.

Parameter name Type Description
Global parametersdefined once and applied to all jobs
redshift_query_logs.global.s3_prefix String The Amazon S3 path where the query logs are exported. Under this path, each exported table is partitioned by cluster name and date.
redshift_query_logs.global.tempdir String The Amazon S3 path that AWS Glue ETL jobs use for temporarily staging the data.
redshift_query_logs.global.role> String The name of the role that the AWS Glue ETL jobs assume. Just the role name is sufficient. The complete Amazon Resource Name (ARN) is not required.
redshift_query_logs.global.enabled_cluster_list StringList A comma-separated list of cluster names for which system tables’ data export is enabled. This gives flexibility for a user to exclude certain clusters.
Cluster-specific parametersfor each cluster specified in the enabled_cluster_list parameter
redshift_query_logs.<<cluster_name>>.connection String The name of the AWS Glue Data Catalog connection to the Amazon Redshift cluster. For example, if the cluster name is product_warehouse, the entry is redshift_query_logs.product_warehouse.connection.
redshift_query_logs.<<cluster_name>>.user String The user name that AWS Glue uses to connect to the Amazon Redshift cluster.
redshift_query_logs.<<cluster_name>>.password Secure String The password that AWS Glue uses to connect the Amazon Redshift cluster’s encrypted-by key that is managed in AWS KMS.

For example, suppose that you have two Amazon Redshift clusters, product-warehouse and category-management, for which the solution described in this post is enabled. In this case, the parameters shown in the following screenshot are created by the solution deployment CloudFormation template in the AWS Systems Manager parameter store.

Solution deployment

To make it easier for you to get started, I created a CloudFormation template that automatically configures and deploys the solution—only one step is required after deployment.

Prerequisites

To deploy the solution, you must have one or more Amazon Redshift clusters in a private subnet. This subnet must have a network address translation (NAT) gateway or a NAT instance configured, and also a security group with a self-referencing inbound rule for all TCP ports. For more information about why AWS Glue ETL needs the configuration it does, described previously, see Connecting to a JDBC Data Store in a VPC in the AWS Glue documentation.

To start the deployment, launch the CloudFormation template:

CloudFormation stack parameters

The following table lists and describes the parameters for deploying the solution to export query logs from multiple Amazon Redshift clusters.

Property Default Description
S3Bucket mybucket The bucket this solution uses to store the exported query logs, stage code artifacts, and perform unloads from Amazon Redshift. For example, the mybucket/extract_rs_logs/data bucket is used for storing all the exported query logs for each system table partitioned by the cluster. The mybucket/extract_rs_logs/temp/ bucket is used for temporarily staging the unloaded data from Amazon Redshift. The mybucket/extract_rs_logs/code bucket is used for storing all the code artifacts required for Lambda and the AWS Glue ETL jobs.
ExportEnabledRedshiftClusters Requires Input A comma-separated list of cluster names from which the system table logs need to be exported.
DataStoreSecurityGroups Requires Input A list of security groups with an inbound rule to the Amazon Redshift clusters provided in the parameter, ExportEnabledClusters. These security groups should also have a self-referencing inbound rule on all TCP ports, as explained on Connecting to a JDBC Data Store in a VPC.

After you launch the template and create the stack, you see that the following resources have been created:

  1. AWS Glue connections for each Amazon Redshift cluster you provided in the CloudFormation stack parameter, ExportEnabledRedshiftClusters.
  2. All parameters required for this solution created in the parameter store.
  3. The Lambda function that invokes the AWS Glue ETL jobs for each configured Amazon Redshift cluster at a regular interval of five minutes.
  4. The DynamoDB table that captures the last exported time stamps for each exported cluster-table combination.
  5. The AWS Glue ETL jobs to export query logs from each Amazon Redshift cluster provided in the CloudFormation stack parameter, ExportEnabledRedshiftClusters.
  6. The IAM roles and policies required for the Lambda function and AWS Glue ETL jobs.

After the deployment

For each Amazon Redshift cluster for which you enabled the solution through the CloudFormation stack parameter, ExportEnabledRedshiftClusters, the automated deployment includes temporary credentials that you must update after the deployment:

  1. Go to the parameter store.
  2. Note the parameters <<cluster_name>>.user and redshift_query_logs.<<cluster_name>>.password that correspond to each Amazon Redshift cluster for which you enabled this solution. Edit these parameters to replace the placeholder values with the right credentials.

For example, if product-warehouse is one of the clusters for which you enabled system table export, you edit these two parameters with the right user name and password and choose Save parameter.

Querying the exported system tables

Within a few minutes after the solution deployment, you should see Amazon Redshift query logs being exported to the Amazon S3 location, <<S3Bucket_you_provided>>/extract_redshift_query_logs/data/. In that bucket, you should see the eight system tables partitioned by customer name and date: stl_alert_event_log, stl_dlltext, stl_explain, stl_query, stl_querytext, stl_scan, stl_utilitytext, and stl_wlm_query.

To run cross-cluster diagnostic queries on the exported system tables, create external tables in the AWS Glue Data Catalog. To make it easier for you to get started, I provide a CloudFormation template that creates an AWS Glue crawler, which crawls the exported system tables stored in Amazon S3 and builds the external tables in the AWS Glue Data Catalog.

Launch this CloudFormation template to create external tables that correspond to the Amazon Redshift system tables. S3Bucket is the only input parameter required for this stack deployment. Provide the same Amazon S3 bucket name where the system tables’ data is being exported. After you successfully create the stack, you can see the eight tables in the database, redshift_query_logs_db, as shown in the following screenshot.

Now, navigate to the Athena console to run cross-cluster diagnostic queries. The following screenshot shows a diagnostic query executed in Athena that retrieves query alerts logged across multiple Amazon Redshift clusters.

You can build the following example Amazon QuickSight dashboard by running cross-cluster diagnostic queries on Athena to identify the hourly query count and the key query alert events across multiple Amazon Redshift clusters.

How to extend the solution

You can extend this post’s solution in two ways:

  • Add any new Amazon Redshift clusters that you spin up after you deploy the solution.
  • Add other system tables or custom query results to the list of exports from an Amazon Redshift cluster.

Extend the solution to other Amazon Redshift clusters

To extend the solution to more Amazon Redshift clusters, add the three cluster-specific parameters in the AWS Systems Manager parameter store following the guidelines earlier in this post. Modify the redshift_query_logs.global.enabled_cluster_list parameter to append the new cluster to the comma-separated string.

Extend the solution to add other tables or custom queries to an Amazon Redshift cluster

The current solution ships with the export functionality for the following Amazon Redshift system tables:

  • stl_alert_event_log
  • stl_dlltext
  • stl_explain
  • stl_query
  • stl_querytext
  • stl_scan
  • stl_utilitytext
  • stl_wlm_query

You can easily add another system table or custom query by adding a few lines of code to the AWS Glue ETL job, <<cluster-name>_extract_rs_query_logs. For example, suppose that from the product-warehouse Amazon Redshift cluster you want to export orders greater than $2,000. To do so, add the following five lines of code to the AWS Glue ETL job product-warehouse_extract_rs_query_logs, where product-warehouse is your cluster name:

  1. Get the last-processed time-stamp value. The function creates a value if it doesn’t already exist.

salesLastProcessTSValue = functions.getLastProcessedTSValue(trackingEntry=”mydb.sales_2000",job_configs=job_configs)

  1. Run the custom query with the time stamp.

returnDF=functions.runQuery(query="select * from sales s join order o where o.order_amnt > 2000 and sale_timestamp > '{}'".format (salesLastProcessTSValue) ,tableName="mydb.sales_2000",job_configs=job_configs)

  1. Save the results to Amazon S3.

functions.saveToS3(dataframe=returnDF,s3Prefix=s3Prefix,tableName="mydb.sales_2000",partitionColumns=["sale_date"],job_configs=job_configs)

  1. Get the latest time-stamp value from the returned data frame in Step 2.

latestTimestampVal=functions.getMaxValue(returnDF,"sale_timestamp",job_configs)

  1. Update the last-processed time-stamp value in the DynamoDB table.

functions.updateLastProcessedTSValue(“mydb.sales_2000",latestTimestampVal[0],job_configs)

Conclusion

In this post, I demonstrate a serverless solution to retain the system tables’ log data across multiple Amazon Redshift clusters. By using this solution, you can incrementally export the data from system tables into Amazon S3. By performing this export, you can build cross-cluster diagnostic queries, build audit dashboards, and derive insights into capacity planning by using services such as Athena. I also demonstrate how you can extend this solution to other ad hoc query use cases or tables other than system tables by adding a few lines of code.


Additional Reading

If you found this post useful, be sure to check out Using Amazon Redshift Spectrum, Amazon Athena, and AWS Glue with Node.js in Production and Amazon Redshift – 2017 Recap.


About the Author

Karthik Sonti is a senior big data architect at Amazon Web Services. He helps AWS customers build big data and analytical solutions and provides guidance on architecture and best practices.

 

 

 

 

More power to your Pi

Post Syndicated from James Adams original https://www.raspberrypi.org/blog/pi-power-supply-chip/

It’s been just over three weeks since we launched the new Raspberry Pi 3 Model B+. Although the product is branded Raspberry Pi 3B+ and not Raspberry Pi 4, a serious amount of engineering was involved in creating it. The wireless networking, USB/Ethernet hub, on-board power supplies, and BCM2837 chip were all upgraded: together these represent almost all the circuitry on the board! Today, I’d like to tell you about the work that has gone into creating a custom power supply chip for our newest computer.

Raspberry Pi 3 Model B+, with custome power supply chip

The new Raspberry Pi 3B+, sporting a new, custom power supply chip (bottom left-hand corner)

Successful launch

The Raspberry Pi 3B+ has been well received, and we’ve enjoyed hearing feedback from the community as well as reading the various reviews and articles highlighting the solid improvements in wireless networking, Ethernet, CPU, and thermal performance of the new board. Gareth Halfacree’s post here has some particularly nice graphs showing the increased performance as well as how the Pi 3B+ keeps cool under load due to the new CPU package that incorporates a metal heat spreader. The Raspberry Pi production lines at the Sony UK Technology Centre are running at full speed, and it seems most people who want to get hold of the new board are able to find one in stock.

Powering your Pi

One of the most critical but often under-appreciated elements of any electronic product, particularly one such as Raspberry Pi with lots of complex on-board silicon (processor, networking, high-speed memory), is the power supply. In fact, the Raspberry Pi 3B+ has no fewer than six different voltage rails: two at 3.3V — one special ‘quiet’ one for audio, and one for everything else; 1.8V; 1.2V for the LPDDR2 memory; and 1.2V nominal for the CPU core. Note that the CPU voltage is actually raised and lowered on the fly as the speed of the CPU is increased and decreased depending on how hard the it is working. The sixth rail is 5V, which is the master supply that all the others are created from, and the output voltage for the four downstream USB ports; this is what the mains power adaptor is supplying through the micro USB power connector.

Power supply primer

There are two common classes of power supply circuits: linear regulators and switching regulators. Linear regulators work by creating a lower, regulated voltage from a higher one. In simple terms, they monitor the output voltage against an internally generated reference and continually change their own resistance to keep the output voltage constant. Switching regulators work in a different way: they ‘pump’ energy by first storing the energy coming from the source supply in a reactive component (usually an inductor, sometimes a capacitor) and then releasing it to the regulated output supply. The switches in switching regulators effect this energy transfer by first connecting the inductor (or capacitor) to store the source energy, and then switching the circuit so the energy is released to its destination.

Linear regulators produce smoother, less noisy output voltages, but they can only convert to a lower voltage, and have to dissipate energy to do so. The higher the output current and the voltage difference across them is, the more energy is lost as heat. On the other hand, switching supplies can, depending on their design, convert any voltage to any other voltage and can be much more efficient (efficiencies of 90% and above are not uncommon). However, they are more complex and generate noisier output voltages.

Designers use both types of regulators depending on the needs of the downstream circuit: for low-voltage drops, low current, or low noise, linear regulators are usually the right choice, while switching regulators are used for higher power or when efficiency of conversion is required. One of the simplest switching-mode power supply circuits is the buck converter, used to create a lower voltage from a higher one, and this is what we use on the Pi.

A history lesson

The BCM2835 processor chip (found on the original Raspberry Pi Model B and B+, as well as on the Zero products) has on-chip power supplies: one switch-mode regulator for the core voltage, as well as a linear one for the LPDDR2 memory supply. This meant that in addition to 5V, we only had to provide 3.3V and 1.8V on the board, which was relatively simple to do using cheap, off-the-shelf parts.

Pi Zero sporting a BCM2835 processor which only needs 2 external switchers (the components clustered behind the camera port)

When we moved to the BCM2836 for Raspberry Pi Model 2 (and subsequently to the BCM2837A1 and B0 for Raspberry Pi 3B and 3B+), the core supply and the on-chip LPDDR2 memory supply were not up to the job of supplying the extra processor cores and larger memory, so we removed them. (We also used the recovered chip area to help fit in the new quad-core ARM processors.) The upshot of this was that we had to supply these power rails externally for the Raspberry Pi 2 and models thereafter. Moreover, we also had to provide circuitry to sequence them correctly in order to control exactly when they power up compared to the other supplies on the board.

Power supply design is tricky (but critical)

Raspberry Pi boards take in 5V from the micro USB socket and have to generate the other required supplies from this. When 5V is first connected, each of these other supplies must ‘start up’, meaning go from ‘off’, or 0V, to their correct voltage in some short period of time. The order of the supplies starting up is often important: commonly, there are structures inside a chip that form diodes between supply rails, and bringing supplies up in the wrong order can sometimes ‘turn on’ these diodes, causing them to conduct, with undesirable consequences. Silicon chips come with a data sheet specifying what supplies (voltages and currents) are needed and whether they need to be low-noise, in what order they must power up (and in some cases down), and sometimes even the rate at which the voltages must power up and down.

A Pi3. Power supply components are clustered bottom left next to the micro USB, middle (above LPDDR2 chip which is on the bottom of the PCB) and above the A/V jack.

In designing the power chain for the Pi 2 and 3, the sequencing was fairly straightforward: power rails power up in order of voltage (5V, 3.3V, 1.8V, 1.2V). However, the supplies were all generated with individual, discrete devices. Therefore, I spent quite a lot of time designing circuitry to control the sequencing — even with some design tricks to reduce component count, quite a few sequencing components are required. More complex systems generally use a Power Management Integrated Circuit (PMIC) with multiple supplies on a single chip, and many different PMIC variants are made by various manufacturers. Since Raspberry Pi 2 days, I was looking for a suitable PMIC to simplify the Pi design, but invariably (and somewhat counter-intuitively) these were always too expensive compared to my discrete solution, usually because they came with more features than needed.

One device to rule them all

It was way back in May 2015 when I first chatted to Peter Coyle of Exar (Exar were bought by MaxLinear in 2017) about power supply products for Raspberry Pi. We didn’t find a product match then, but in June 2016 Peter, along with Tuomas Hollman and Trevor Latham, visited to pitch the possibility of building a custom power management solution for us.

I was initially sceptical that it could be made cheap enough. However, our discussion indicated that if we could tailor the solution to just what we needed, it could be cost-effective. Over the coming weeks and months, we honed a specification we agreed on from the initial sketches we’d made, and Exar thought they could build it for us at the target price.

The chip we designed would contain all the key supplies required for the Pi on one small device in a cheap QFN package, and it would also perform the required sequencing and voltage monitoring. Moreover, the chip would be flexible to allow adjustment of supply voltages from their default values via I2C; the largest supply would be capable of being adjusted quickly to perform the dynamic core voltage changes needed in order to reduce voltage to the processor when it is idling (to save power), and to boost voltage to the processor when running at maximum speed (1.4 GHz). The supplies on the chip would all be generously specified and could deliver significantly more power than those used on the Raspberry Pi 3. All in all, the chip would contain four switching-mode converters and one low-current linear regulator, this last one being low-noise for the audio circuitry.

The MXL7704 chip

The project was a great success: MaxLinear delivered working samples of first silicon at the end of May 2017 (almost exactly a year after we had kicked off the project), and followed through with production quantities in December 2017 in time for the Raspberry Pi 3B+ production ramp.

The team behind the power supply chip on the Raspberry Pi 3 Model B+ (group of six men, two of whom are holding Raspberry Pi boards)

Front row: Roger with the very first Pi 3B+ prototypes and James with a MXL7704 development board hacked to power a Pi 3. Back row left to right: Will Torgerson, Trevor Latham, Peter Coyle, Tuomas Hollman.

The MXL7704 device has been key to reducing Pi board complexity and therefore overall bill of materials cost. Furthermore, by being able to deliver more power when needed, it has also been essential to increasing the speed of the (newly packaged) BCM2837B0 processor on the 3B+ to 1.4GHz. The result is improvements to both the continuous output current to the CPU (from 3A to 4A) and to the transient performance (i.e. the chip has helped to reduce the ‘transient response’, which is the change in supply voltage due to a sudden current spike that occurs when the processor suddenly demands a large current in a few nanoseconds, as modern CPUs tend to do).

With the MXL7704, the power supply circuitry on the 3B+ is now a lot simpler than the Pi 3B design. This new supply also provides the LPDDR2 memory voltage directly from a switching regulator rather than using linear regulators like the Pi 3, thereby improving energy efficiency. This helps to somewhat offset the extra power that the faster Ethernet, wireless networking, and processor consume. A pleasing side effect of using the new chip is the symmetric board layout of the regulators — it’s easy to see the four switching-mode supplies, given away by four similar-looking blobs (three grey and one brownish), which are the inductors.

Close-up of the power supply chip on the Raspberry Pi 3 Model B+

The Pi 3B+ PMIC MXL7704 — pleasingly symmetric

Kudos

It takes a lot of effort to design a new chip from scratch and get it all the way through to production — we are very grateful to the team at MaxLinear for their hard work, dedication, and enthusiasm. We’re also proud to have created something that will not only power Raspberry Pis, but will also be useful for other product designs: it turns out when you have a low-cost and flexible device, it can be used for many things — something we’re fairly familiar with here at Raspberry Pi! For the curious, the product page (including the data sheet) for the MXL7704 chip is here. Particular thanks go to Peter Coyle, Tuomas Hollman, and Trevor Latham, and also to Jon Cronk, who has been our contact in the US and has had to get up early to attend all our conference calls!

The MXL7704 design team celebrating on Pi Day — it takes a lot of people to design a chip!

I hope you liked reading about some of the effort that has gone into creating the new Pi. It’s nice to finally have a chance to tell people about some of the (increasingly complex) technical work that makes building a $35 computer possible — we’re very pleased with the Raspberry Pi 3B+, and we hope you enjoy using it as much as we’ve enjoyed creating it!

The post More power to your Pi appeared first on Raspberry Pi.

Securing messages published to Amazon SNS with AWS PrivateLink

Post Syndicated from Otavio Ferreira original https://aws.amazon.com/blogs/security/securing-messages-published-to-amazon-sns-with-aws-privatelink/

Amazon Simple Notification Service (SNS) now supports VPC Endpoints (VPCE) via AWS PrivateLink. You can use VPC Endpoints to privately publish messages to SNS topics, from an Amazon Virtual Private Cloud (VPC), without traversing the public internet. When you use AWS PrivateLink, you don’t need to set up an Internet Gateway (IGW), Network Address Translation (NAT) device, or Virtual Private Network (VPN) connection. You don’t need to use public IP addresses, either.

VPC Endpoints doesn’t require code changes and can bring additional security to Pub/Sub Messaging use cases that rely on SNS. VPC Endpoints helps promote data privacy and is aligned with assurance programs, including the Health Insurance Portability and Accountability Act (HIPAA), FedRAMP, and others discussed below.

VPC Endpoints for SNS in action

Here’s how VPC Endpoints for SNS works. The following example is based on a banking system that processes mortgage applications. This banking system, which has been deployed to a VPC, publishes each mortgage application to an SNS topic. The SNS topic then fans out the mortgage application message to two subscribing AWS Lambda functions:

  • Save-Mortgage-Application stores the application in an Amazon DynamoDB table. As the mortgage application contains personally identifiable information (PII), the message must not traverse the public internet.
  • Save-Credit-Report checks the applicant’s credit history against an external Credit Reporting Agency (CRA), then stores the final credit report in an Amazon S3 bucket.

The following diagram depicts the underlying architecture for this banking system:
 
Diagram depicting the architecture for the example banking system
 
To protect applicants’ data, the financial institution responsible for developing this banking system needed a mechanism to prevent PII data from traversing the internet when publishing mortgage applications from their VPC to the SNS topic. Therefore, they created a VPC endpoint to enable their publisher Amazon EC2 instance to privately connect to the SNS API. As shown in the diagram, when the VPC endpoint is created, an Elastic Network Interface (ENI) is automatically placed in the same VPC subnet as the publisher EC2 instance. This ENI exposes a private IP address that is used as the entry point for traffic destined to SNS. This ensures that traffic between the VPC and SNS doesn’t leave the Amazon network.

Set up VPC Endpoints for SNS

The process for creating a VPC endpoint to privately connect to SNS doesn’t require code changes: access the VPC Management Console, navigate to the Endpoints section, and create a new Endpoint. Three attributes are required:

  • The SNS service name.
  • The VPC and Availability Zones (AZs) from which you’ll publish your messages.
  • The Security Group (SG) to be associated with the endpoint network interface. The Security Group controls the traffic to the endpoint network interface from resources in your VPC. If you don’t specify a Security Group, the default Security Group for your VPC will be associated.

Help ensure your security and compliance

SNS can support messaging use cases in regulated market segments, such as healthcare provider systems subject to the Health Insurance Portability and Accountability Act (HIPAA) and financial systems subject to the Payment Card Industry Data Security Standard (PCI DSS), and is also in-scope with the following Assurance Programs:

The SNS API is served through HTTP Secure (HTTPS), and encrypts all messages in transit with Transport Layer Security (TLS) certificates issued by Amazon Trust Services (ATS). The certificates verify the identity of the SNS API server when encrypted connections are established. The certificates help establish proof that your SNS API client (SDK, CLI) is communicating securely with the SNS API server. A Certificate Authority (CA) issues the certificate to a specific domain. Hence, when a domain presents a certificate that’s issued by a trusted CA, the SNS API client knows it’s safe to make the connection.

Summary

VPC Endpoints can increase the security of your pub/sub messaging use cases by allowing you to publish messages to SNS topics, from instances in your VPC, without traversing the internet. Setting up VPC Endpoints for SNS doesn’t require any code changes because the SNS API address remains the same.

VPC Endpoints for SNS is now available in all AWS Regions where AWS PrivateLink is available. For information on pricing and regional availability, visit the VPC pricing page.
For more information and on-boarding, see Publishing to Amazon SNS Topics from Amazon Virtual Private Cloud in the SNS documentation.

If you have comments about this post, submit them in the Comments section below. If you have questions about anything in this post, start a new thread on the Amazon SNS forum or contact AWS Support.

Want more AWS Security news? Follow us on Twitter.

Amazon Translate Now Generally Available

Post Syndicated from Randall Hunt original https://aws.amazon.com/blogs/aws/amazon-translate-now-generally-available/


Today we’re excited to make Amazon Translate generally available. Late last year at AWS re:Invent my colleague Tara Walker wrote about a preview of a new AI service, Amazon Translate. Starting today you can access Amazon Translate in US East (N. Virginia), US East (Ohio), US West (Oregon), and EU (Ireland) with a 2 million character monthly free tier for the first 12 months and $15 per million characters after that. There are a number of new features available in GA: automatic source language inference, Amazon CloudWatch support, and up to 5000 characters in a single TranslateText call. Let’s take a quick look at the service in general availability.

Amazon Translate New Features

Since Tara’s post already covered the basics of the service I want to point out some of the new features of the service released today. Let’s start with a code sample:

import boto3
translate = boto3.client("translate")
resp = translate.translate_text(
    Text="🇫🇷Je suis très excité pour Amazon Traduire🇫🇷",
    SourceLanguageCode="auto",
    TargetLanguageCode="en"
)
print(resp['TranslatedText'])

Since I have specified my source language as auto, Amazon Translate will call Amazon Comprehend on my behalf to determine the source language used in this text. If you couldn’t guess it, we’re writing some French and the output is 🇫🇷I'm very excited about Amazon Translate 🇫🇷. You’ll notice that our emojis are preserved in the output text which is definitely a bonus feature for Millennials like me.

The Translate console is a great way to get started and see some sample response.

Translate is extremely easy to use in AWS Lambda functions which allows you to use it with almost any AWS service. There are a number of examples in the Translate documentation showing how to do everything from translate a web page to a Amazon DynamoDB table. Paired with other ML services like Amazon Comprehend and [transcribe] you can build everything from closed captioning to real-time chat translation to a robust text analysis pipeline for call centers transcriptions and other textual data.

New Languages Coming Soon

Today, Amazon Translate allows you to translate text to or from English, to any of the following languages: Arabic, Chinese (Simplified), French, German, Portuguese, and Spanish. We’ve announced support for additional languages coming soon: Japanese (go JAWSUG), Russian, Italian, Chinese (Traditional), Turkish, and Czech.

Amazon Translate can also be used to increase professional translator efficiency, and reduce costs and turnaround times for their clients. We’ve already partnered with a number of Language Service Providers (LSPs) to offer their customers end-to-end translation services at a lower cost by allowing Amazon Translate to produce a high-quality draft translation that’s then edited by the LSP for a guaranteed human quality result.

I’m excited to see what applications our customers are able to build with high quality machine translation just one API call away.

Randall

Innovation Flywheels and the AWS Serverless Application Repository

Post Syndicated from Tim Wagner original https://aws.amazon.com/blogs/compute/innovation-flywheels-and-the-aws-serverless-application-repository/

At AWS, our customers have always been the motivation for our innovation. In turn, we’re committed to helping them accelerate the pace of their own innovation. It was in the spirit of helping our customers achieve their objectives faster that we launched AWS Lambda in 2014, eliminating the burden of server management and enabling AWS developers to focus on business logic instead of the challenges of provisioning and managing infrastructure.

 

In the years since, our customers have built amazing things using Lambda and other serverless offerings, such as Amazon API Gateway, Amazon Cognito, and Amazon DynamoDB. Together, these services make it easy to build entire applications without the need to provision, manage, monitor, or patch servers. By removing much of the operational drudgery of infrastructure management, we’ve helped our customers become more agile and achieve faster time-to-market for their applications and services. By eliminating cold servers and cold containers with request-based pricing, we’ve also eliminated the high cost of idle capacity and helped our customers achieve dramatically higher utilization and better economics.

After we launched Lambda, though, we quickly learned an important lesson: A single Lambda function rarely exists in isolation. Rather, many functions are part of serverless applications that collectively deliver customer value. Whether it’s the combination of event sources and event handlers, as serverless web apps that combine APIs with functions for dynamic content with static content repositories, or collections of functions that together provide a microservice architecture, our customers were building and delivering serverless architectures for every conceivable problem. Despite the economic and agility benefits that hundreds of thousands of AWS customers were enjoying with Lambda, we realized there was still more we could do.

How Customer Feedback Inspired Us to Innovate

We heard from our customers that getting started—either from scratch or when augmenting their implementation with new techniques or technologies—remained a challenge. When we looked for serverless assets to share, we found stellar examples built by serverless pioneers that represented a multitude of solutions across industries.

There were apps to facilitate monitoring and logging, to process image and audio files, to create Alexa skills, and to integrate with notification and location services. These apps ranged from “getting started” examples to complete, ready-to-run assets. What was missing, however, was a unified place for customers to discover this diversity of serverless applications and a step-by-step interface to help them configure and deploy them.

We also heard from customers and partners that building their own ecosystems—ecosystems increasingly composed of functions, APIs, and serverless applications—remained a challenge. They wanted a simple way to share samples, create extensibility, and grow consumer relationships on top of serverless approaches.

 

We built the AWS Serverless Application Repository to help solve both of these challenges by offering publishers and consumers of serverless apps a simple, fast, and effective way to share applications and grow user communities around them. Now, developers can easily learn how to apply serverless approaches to their implementation and business challenges by discovering, customizing, and deploying serverless applications directly from the Serverless Application Repository. They can also find libraries, components, patterns, and best practices that augment their existing knowledge, helping them bring services and applications to market faster than ever before.

How the AWS Serverless Application Repository Inspires Innovation for All Customers

Companies that want to create ecosystems, share samples, deliver extensibility and customization options, and complement their existing SaaS services use the Serverless Application Repository as a distribution channel, producing apps that can be easily discovered and consumed by their customers. AWS partners like HERE have introduced their location and transit services to thousands of companies and developers. Partners like Datadog, Splunk, and TensorIoT have showcased monitoring, logging, and IoT applications to the serverless community.

Individual developers are also publishing serverless applications that push the boundaries of innovation—some have published applications that leverage machine learning to predict the quality of wine while others have published applications that monitor crypto-currencies, instantly build beautiful image galleries, or create fast and simple surveys. All of these publishers are using serverless apps, and the Serverless Application Repository, as the easiest way to share what they’ve built. Best of all, their customers and fellow community members can find and deploy these applications with just a few clicks in the Lambda console. Apps in the Serverless Application Repository are free of charge, making it easy to explore new solutions or learn new technologies.

Finally, we at AWS continue to publish apps for the community to use. From apps that leverage Amazon Cognito to sync user data across applications to our latest collection of serverless apps that enable users to quickly execute common financial calculations, we’re constantly looking for opportunities to contribute to community growth and innovation.

At AWS, we’re more excited than ever by the growing adoption of serverless architectures and the innovation that services like AWS Lambda make possible. Helping our customers create and deliver new ideas drives us to keep inventing ways to make building and sharing serverless apps even easier. As the number of applications in the Serverless Application Repository grows, so too will the innovation that it fuels for both the owners and the consumers of those apps. With the general availability of the Serverless Application Repository, our customers become more than the engine of our innovation—they become the engine of innovation for one another.

To browse, discover, deploy, and publish serverless apps in minutes, visit the Serverless Application Repository. Go serverless—and go innovate!

Dr. Tim Wagner is the General Manager of AWS Lambda and Amazon API Gateway.

Performing Unit Testing in an AWS CodeStar Project

Post Syndicated from Jerry Mathen Jacob original https://aws.amazon.com/blogs/devops/performing-unit-testing-in-an-aws-codestar-project/

In this blog post, I will show how you can perform unit testing as a part of your AWS CodeStar project. AWS CodeStar helps you quickly develop, build, and deploy applications on AWS. With AWS CodeStar, you can set up your continuous delivery (CD) toolchain and manage your software development from one place.

Because unit testing tests individual units of application code, it is helpful for quickly identifying and isolating issues. As a part of an automated CI/CD process, it can also be used to prevent bad code from being deployed into production.

Many of the AWS CodeStar project templates come preconfigured with a unit testing framework so that you can start deploying your code with more confidence. The unit testing is configured to run in the provided build stage so that, if the unit tests do not pass, the code is not deployed. For a list of AWS CodeStar project templates that include unit testing, see AWS CodeStar Project Templates in the AWS CodeStar User Guide.

The scenario

As a big fan of superhero movies, I decided to list my favorites and ask my friends to vote on theirs by using a WebService endpoint I created. The example I use is a Python web service running on AWS Lambda with AWS CodeCommit as the code repository. CodeCommit is a fully managed source control system that hosts Git repositories and works with all Git-based tools.

Here’s how you can create the WebService endpoint:

Sign in to the AWS CodeStar console. Choose Start a project, which will take you to the list of project templates.

create project

For code edits I will choose AWS Cloud9, which is a cloud-based integrated development environment (IDE) that you use to write, run, and debug code.

choose cloud9

Here are the other tasks required by my scenario:

  • Create a database table where the votes can be stored and retrieved as needed.
  • Update the logic in the Lambda function that was created for posting and getting the votes.
  • Update the unit tests (of course!) to verify that the logic works as expected.

For a database table, I’ve chosen Amazon DynamoDB, which offers a fast and flexible NoSQL database.

Getting set up on AWS Cloud9

From the AWS CodeStar console, go to the AWS Cloud9 console, which should take you to your project code. I will open up a terminal at the top-level folder under which I will set up my environment and required libraries.

Use the following command to set the PYTHONPATH environment variable on the terminal.

export PYTHONPATH=/home/ec2-user/environment/vote-your-movie

You should now be able to use the following command to execute the unit tests in your project.

python -m unittest discover vote-your-movie/tests

cloud9 setup

Start coding

Now that you have set up your local environment and have a copy of your code, add a DynamoDB table to the project by defining it through a template file. Open template.yml, which is the Serverless Application Model (SAM) template file. This template extends AWS CloudFormation to provide a simplified way of defining the Amazon API Gateway APIs, AWS Lambda functions, and Amazon DynamoDB tables required by your serverless application.

AWSTemplateFormatVersion: 2010-09-09
Transform:
- AWS::Serverless-2016-10-31
- AWS::CodeStar

Parameters:
  ProjectId:
    Type: String
    Description: CodeStar projectId used to associate new resources to team members

Resources:
  # The DB table to store the votes.
  MovieVoteTable:
    Type: AWS::Serverless::SimpleTable
    Properties:
      PrimaryKey:
        # Name of the "Candidate" is the partition key of the table.
        Name: Candidate
        Type: String
  # Creating a new lambda function for retrieving and storing votes.
  MovieVoteLambda:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: python3.6
      Environment:
        # Setting environment variables for your lambda function.
        Variables:
          TABLE_NAME: !Ref "MovieVoteTable"
          TABLE_REGION: !Ref "AWS::Region"
      Role:
        Fn::ImportValue:
          !Join ['-', [!Ref 'ProjectId', !Ref 'AWS::Region', 'LambdaTrustRole']]
      Events:
        GetEvent:
          Type: Api
          Properties:
            Path: /
            Method: get
        PostEvent:
          Type: Api
          Properties:
            Path: /
            Method: post

We’ll use Python’s boto3 library to connect to AWS services. And we’ll use Python’s mock library to mock AWS service calls for our unit tests.
Use the following command to install these libraries:

pip install --upgrade boto3 mock -t .

install dependencies

Add these libraries to the buildspec.yml, which is the YAML file that is required for CodeBuild to execute.

version: 0.2

phases:
  install:
    commands:

      # Upgrade AWS CLI to the latest version
      - pip install --upgrade awscli boto3 mock

  pre_build:
    commands:

      # Discover and run unit tests in the 'tests' directory. For more information, see <https://docs.python.org/3/library/unittest.html#test-discovery>
      - python -m unittest discover tests

  build:
    commands:

      # Use AWS SAM to package the application by using AWS CloudFormation
      - aws cloudformation package --template template.yml --s3-bucket $S3_BUCKET --output-template template-export.yml

artifacts:
  type: zip
  files:
    - template-export.yml

Open the index.py where we can write the simple voting logic for our Lambda function.

import json
import datetime
import boto3
import os

table_name = os.environ['TABLE_NAME']
table_region = os.environ['TABLE_REGION']

VOTES_TABLE = boto3.resource('dynamodb', region_name=table_region).Table(table_name)
CANDIDATES = {"A": "Black Panther", "B": "Captain America: Civil War", "C": "Guardians of the Galaxy", "D": "Thor: Ragnarok"}

def handler(event, context):
    if event['httpMethod'] == 'GET':
        resp = VOTES_TABLE.scan()
        return {'statusCode': 200,
                'body': json.dumps({item['Candidate']: int(item['Votes']) for item in resp['Items']}),
                'headers': {'Content-Type': 'application/json'}}

    elif event['httpMethod'] == 'POST':
        try:
            body = json.loads(event['body'])
        except:
            return {'statusCode': 400,
                    'body': 'Invalid input! Expecting a JSON.',
                    'headers': {'Content-Type': 'application/json'}}
        if 'candidate' not in body:
            return {'statusCode': 400,
                    'body': 'Missing "candidate" in request.',
                    'headers': {'Content-Type': 'application/json'}}
        if body['candidate'] not in CANDIDATES.keys():
            return {'statusCode': 400,
                    'body': 'You must vote for one of the following candidates - {}.'.format(get_allowed_candidates()),
                    'headers': {'Content-Type': 'application/json'}}

        resp = VOTES_TABLE.update_item(
            Key={'Candidate': CANDIDATES.get(body['candidate'])},
            UpdateExpression='ADD Votes :incr',
            ExpressionAttributeValues={':incr': 1},
            ReturnValues='ALL_NEW'
        )
        return {'statusCode': 200,
                'body': "{} now has {} votes".format(CANDIDATES.get(body['candidate']), resp['Attributes']['Votes']),
                'headers': {'Content-Type': 'application/json'}}

def get_allowed_candidates():
    l = []
    for key in CANDIDATES:
        l.append("'{}' for '{}'".format(key, CANDIDATES.get(key)))
    return ", ".join(l)

What our code basically does is take in the HTTPS request call as an event. If it is an HTTP GET request, it gets the votes result from the table. If it is an HTTP POST request, it sets a vote for the candidate of choice. We also validate the inputs in the POST request to filter out requests that seem malicious. That way, only valid calls are stored in the table.

In the example code provided, we use a CANDIDATES variable to store our candidates, but you can store the candidates in a JSON file and use Python’s json library instead.

Let’s update the tests now. Under the tests folder, open the test_handler.py and modify it to verify the logic.

import os
# Some mock environment variables that would be used by the mock for DynamoDB
os.environ['TABLE_NAME'] = "MockHelloWorldTable"
os.environ['TABLE_REGION'] = "us-east-1"

# The library containing our logic.
import index

# Boto3's core library
import botocore
# For handling JSON.
import json
# Unit test library
import unittest
## Getting StringIO based on your setup.
try:
    from StringIO import StringIO
except ImportError:
    from io import StringIO
## Python mock library
from mock import patch, call
from decimal import Decimal

@patch('botocore.client.BaseClient._make_api_call')
class TestCandidateVotes(unittest.TestCase):

    ## Test the HTTP GET request flow. 
    ## We expect to get back a successful response with results of votes from the table (mocked).
    def test_get_votes(self, boto_mock):
        # Input event to our method to test.
        expected_event = {'httpMethod': 'GET'}
        # The mocked values in our DynamoDB table.
        items_in_db = [{'Candidate': 'Black Panther', 'Votes': Decimal('3')},
                        {'Candidate': 'Captain America: Civil War', 'Votes': Decimal('8')},
                        {'Candidate': 'Guardians of the Galaxy', 'Votes': Decimal('8')},
                        {'Candidate': "Thor: Ragnarok", 'Votes': Decimal('1')}
                    ]
        # The mocked DynamoDB response.
        expected_ddb_response = {'Items': items_in_db}
        # The mocked response we expect back by calling DynamoDB through boto.
        response_body = botocore.response.StreamingBody(StringIO(str(expected_ddb_response)),
                                                        len(str(expected_ddb_response)))
        # Setting the expected value in the mock.
        boto_mock.side_effect = [expected_ddb_response]
        # Expecting that there would be a call to DynamoDB Scan function during execution with these parameters.
        expected_calls = [call('Scan', {'TableName': os.environ['TABLE_NAME']})]

        # Call the function to test.
        result = index.handler(expected_event, {})

        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 200

        result_body = json.loads(result.get('body'))
        # Verifying that the results match to that from the table.
        assert len(result_body) == len(items_in_db)
        for i in range(len(result_body)):
            assert result_body.get(items_in_db[i].get("Candidate")) == int(items_in_db[i].get("Votes"))

        assert boto_mock.call_count == 1
        boto_mock.assert_has_calls(expected_calls)

    ## Test the HTTP POST request flow that places a vote for a selected candidate.
    ## We expect to get back a successful response with a confirmation message.
    def test_place_valid_candidate_vote(self, boto_mock):
        # Input event to our method to test.
        expected_event = {'httpMethod': 'POST', 'body': "{\"candidate\": \"D\"}"}
        # The mocked response in our DynamoDB table.
        expected_ddb_response = {'Attributes': {'Candidate': "Thor: Ragnarok", 'Votes': Decimal('2')}}
        # The mocked response we expect back by calling DynamoDB through boto.
        response_body = botocore.response.StreamingBody(StringIO(str(expected_ddb_response)),
                                                        len(str(expected_ddb_response)))
        # Setting the expected value in the mock.
        boto_mock.side_effect = [expected_ddb_response]
        # Expecting that there would be a call to DynamoDB UpdateItem function during execution with these parameters.
        expected_calls = [call('UpdateItem', {
                                                'TableName': os.environ['TABLE_NAME'], 
                                                'Key': {'Candidate': 'Thor: Ragnarok'},
                                                'UpdateExpression': 'ADD Votes :incr',
                                                'ExpressionAttributeValues': {':incr': 1},
                                                'ReturnValues': 'ALL_NEW'
                                            })]
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 200

        assert result.get('body') == "{} now has {} votes".format(
            expected_ddb_response['Attributes']['Candidate'], 
            expected_ddb_response['Attributes']['Votes'])

        assert boto_mock.call_count == 1
        boto_mock.assert_has_calls(expected_calls)

    ## Test the HTTP POST request flow that places a vote for an non-existant candidate.
    ## We expect to get back a successful response with a confirmation message.
    def test_place_invalid_candidate_vote(self, boto_mock):
        # Input event to our method to test.
        # The valid IDs for the candidates are A, B, C, and D
        expected_event = {'httpMethod': 'POST', 'body': "{\"candidate\": \"E\"}"}
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 400
        assert result.get('body') == 'You must vote for one of the following candidates - {}.'.format(index.get_allowed_candidates())

    ## Test the HTTP POST request flow that places a vote for a selected candidate but associated with an invalid key in the POST body.
    ## We expect to get back a failed (400) response with an appropriate error message.
    def test_place_invalid_data_vote(self, boto_mock):
        # Input event to our method to test.
        # "name" is not the expected input key.
        expected_event = {'httpMethod': 'POST', 'body': "{\"name\": \"D\"}"}
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 400
        assert result.get('body') == 'Missing "candidate" in request.'

    ## Test the HTTP POST request flow that places a vote for a selected candidate but not as a JSON string which the body of the request expects.
    ## We expect to get back a failed (400) response with an appropriate error message.
    def test_place_malformed_json_vote(self, boto_mock):
        # Input event to our method to test.
        # "body" receives a string rather than a JSON string.
        expected_event = {'httpMethod': 'POST', 'body': "Thor: Ragnarok"}
        # Call the function to test.
        result = index.handler(expected_event, {})
        # Run unit test assertions to verify the expected calls to mock have occurred and verify the response.
        assert result.get('headers').get('Content-Type') == 'application/json'
        assert result.get('statusCode') == 400
        assert result.get('body') == 'Invalid input! Expecting a JSON.'

if __name__ == '__main__':
    unittest.main()

I am keeping the code samples well commented so that it’s clear what each unit test accomplishes. It tests the success conditions and the failure paths that are handled in the logic.

In my unit tests I use the patch decorator (@patch) in the mock library. @patch helps mock the function you want to call (in this case, the botocore library’s _make_api_call function in the BaseClient class).
Before we commit our changes, let’s run the tests locally. On the terminal, run the tests again. If all the unit tests pass, you should expect to see a result like this:

You:~/environment $ python -m unittest discover vote-your-movie/tests
.....
----------------------------------------------------------------------
Ran 5 tests in 0.003s

OK
You:~/environment $

Upload to AWS

Now that the tests have passed, it’s time to commit and push the code to source repository!

Add your changes

From the terminal, go to the project’s folder and use the following command to verify the changes you are about to push.

git status

To add the modified files only, use the following command:

git add -u

Commit your changes

To commit the changes (with a message), use the following command:

git commit -m "Logic and tests for the voting webservice."

Push your changes to AWS CodeCommit

To push your committed changes to CodeCommit, use the following command:

git push

In the AWS CodeStar console, you can see your changes flowing through the pipeline and being deployed. There are also links in the AWS CodeStar console that take you to this project’s build runs so you can see your tests running on AWS CodeBuild. The latest link under the Build Runs table takes you to the logs.

unit tests at codebuild

After the deployment is complete, AWS CodeStar should now display the AWS Lambda function and DynamoDB table created and synced with this project. The Project link in the AWS CodeStar project’s navigation bar displays the AWS resources linked to this project.

codestar resources

Because this is a new database table, there should be no data in it. So, let’s put in some votes. You can download Postman to test your application endpoint for POST and GET calls. The endpoint you want to test is the URL displayed under Application endpoints in the AWS CodeStar console.

Now let’s open Postman and look at the results. Let’s create some votes through POST requests. Based on this example, a valid vote has a value of A, B, C, or D.
Here’s what a successful POST request looks like:

POST success

Here’s what it looks like if I use some value other than A, B, C, or D:

 

POST Fail

Now I am going to use a GET request to fetch the results of the votes from the database.

GET success

And that’s it! You have now created a simple voting web service using AWS Lambda, Amazon API Gateway, and DynamoDB and used unit tests to verify your logic so that you ship good code.
Happy coding!

How to migrate a Hue database from an existing Amazon EMR cluster

Post Syndicated from Anvesh Ragi original https://aws.amazon.com/blogs/big-data/how-to-migrate-a-hue-database-from-an-existing-amazon-emr-cluster/

Hadoop User Experience (Hue) is an open-source, web-based, graphical user interface for use with Amazon EMR and Apache Hadoop. The Hue database stores things like users, groups, authorization permissions, Apache Hive queries, Apache Oozie workflows, and so on.

There might come a time when you want to migrate your Hue database to a new EMR cluster. For example, you might want to upgrade from an older version of the Amazon EMR AMI (Amazon Machine Image), but your Hue application and its database have had a lot of customization.You can avoid re-creating these user entities and retain query/workflow histories in Hue by migrating the existing Hue database, or remote database in Amazon RDS, to a new cluster.

By default, Hue user information and query histories are stored in a local MySQL database on the EMR cluster’s master node. However, you can create one or more Hue-enabled clusters using a configuration stored in Amazon S3 and a remote MySQL database in Amazon RDS. This allows you to preserve user information and query history that Hue creates without keeping your Amazon EMR cluster running.

This post describes the step-by-step process for migrating the Hue database from an existing EMR cluster.

Note: Amazon EMR supports different Hue versions across different AMI releases. Keep in mind the compatibility of Hue versions between the old and new clusters in this migration activity. Currently, Hue 3.x.x versions are not compatible with Hue 4.x.x versions, and therefore a migration between these two Hue versions might create issues. In addition, Hue 3.10.0 is not backward compatible with its previous 3.x.x versions.

Before you begin

First, let’s create a new testUser in Hue on an existing EMR cluster, as shown following:

You will use these credentials later to log in to Hue on the new EMR cluster and validate whether you have successfully migrated the Hue database.

Let’s get started!

Migration how-to

Follow these steps to migrate your database to a new EMR cluster and then validate the migration process.

1.) Make a backup of the existing Hue database.

Use SSH to connect to the master node of the old cluster, as shown following (if you are using Linux/Unix/macOS), and dump the Hue database to a JSON file.

$ ssh -i ~/key.pem [email protected]
$ /usr/lib/hue/build/env/bin/hue dumpdata > ./hue-mysql.json

Edit the hue-mysql.json output file by removing all JSON objects that have useradmin.userprofile in the model field, and save the file. For example, remove the objects as shown following:

{
  "pk": 1,
  "model": "useradmin.userprofile",
  "fields": {
    "last_activity": "2018-01-10T11:41:04",
    "creation_method": "HUE",
    "first_login": false,
    "user": 1,
    "home_directory": "/user/hue_admin"
  }
},

2.) Store the hue-mysql.json file on persistent storage like Amazon S3.

You can copy the file from the old EMR cluster to Amazon S3 using the AWS CLI or Secure Copy (SCP) client. For example, the following uses the AWS CLI:

$ aws s3 cp ./hue-mysql.json s3://YourBucketName/folder/

3.) Recover/reload the backed-up Hue database into the new EMR cluster.

a.) Use SSH to connect to the master node of the new EMR cluster, and stop the Hue service that is already running.

$ ssh -i ~/key.pem [email protected]
$ sudo stop hue
hue stop/waiting

b.) Connect to the Hue database—either the local MySQL database or the remote database in Amazon RDS for your cluster as shown following, using the mysql client.

$ mysql -h HOST –u USER –pPASSWORD

For a local MySQL database, you can find the hostname, user name, and password for connecting to the database in the /etc/hue/conf/hue.ini file on the master node.

[[database]]
    engine = mysql
    name = huedb
    case_insensitive_collation = utf8_unicode_ci
    test_charset = utf8
    test_collation = utf8_bin
    host = ip-172-31-37-133.us-west-2.compute.internal
    user = hue
    test_name = test_huedb
    password = QdWbL3Ai6GcBqk26
    port = 3306

Based on the preceding example configuration, the sample command is as follows. (Replace the host, user, and password details based on your EMR cluster settings.)

$ mysql -h ip-172-31-37-133.us-west-2.compute.internal -u hue -pQdWbL3Ai6GcBqk26

c.) Drop the existing Hue database with the name huedb from the MySQL server.

mysql> DROP DATABASE IF EXISTS huedb;

d.) Create a new empty database with the same name huedb.

mysql> CREATE DATABASE huedb DEFAULT CHARACTER SET utf8 DEFAULT COLLATE=utf8_bin;

e.) Now, synchronize Hue with its database huedb.

$ sudo /usr/lib/hue/build/env/bin/hue syncdb --noinput
$ sudo /usr/lib/hue/build/env/bin/hue migrate

(This populates the new huedb with all Hue tables that are required.)

f.) Log in to MySQL again, and drop the foreign key to clean tables.

mysql> SHOW CREATE TABLE huedb.auth_permission;

In the following example, replace <id value> with the actual value from the preceding output.

mysql> ALTER TABLE huedb.auth_permission DROP FOREIGN KEY
content_type_id_refs_id_<id value>;

g.) Delete the contents of the django_content_type

mysql> DELETE FROM huedb.django_content_type;

h.) Download the backed-up Hue database dump from Amazon S3 to the new EMR cluster, and load it into Hue.

$ aws s3 cp s3://YourBucketName/folder/hue-mysql.json ./
$ sudo /usr/lib/hue/build/env/bin/hue loaddata ./hue-mysql.json

i.) In MySQL, add the foreign key content_type_id back to the auth_permission

mysql> use huedb;
mysql> ALTER TABLE huedb.auth_permission ADD FOREIGN KEY (`content_type_id`) REFERENCES `django_content_type` (`id`);

j.) Start the Hue service again.

$ sudo start hue
hue start/running, process XXXX

That’s it! Now, verify whether you can successfully access the Hue UI, and sign in using your existing testUser credentials.

After a successful sign in to Hue on the new EMR cluster, you should see a similar Hue homepage as shown following with testUser as the user signed in:

Conclusion

You have now learned how to migrate an existing Hue database to a new Amazon EMR cluster and validate the migration process. If you have any similar Amazon EMR administration topics that you want to see covered in a future post, please let us know in the comments below.


Additional Reading

If you found this post useful, be sure to check out Anomaly Detection Using PySpark, Hive, and Hue on Amazon EMR and Dynamically Create Friendly URLs for Your Amazon EMR Web Interfaces.


About the Author


Anvesh Ragi is a Big Data Support Engineer with Amazon Web Services. He works closely with AWS customers to provide them architectural and engineering assistance for their data processing workflows. In his free time, he enjoys traveling and going for hikes.

Amazon ECS Service Discovery

Post Syndicated from Randall Hunt original https://aws.amazon.com/blogs/aws/amazon-ecs-service-discovery/

Amazon ECS now includes integrated service discovery. This makes it possible for an ECS service to automatically register itself with a predictable and friendly DNS name in Amazon Route 53. As your services scale up or down in response to load or container health, the Route 53 hosted zone is kept up to date, allowing other services to lookup where they need to make connections based on the state of each service. You can see a demo of service discovery in an imaginary social networking app over at: https://servicediscovery.ranman.com/.

Service Discovery


Part of the transition to microservices and modern architectures involves having dynamic, autoscaling, and robust services that can respond quickly to failures and changing loads. Your services probably have complex dependency graphs of services they rely on and services they provide. A modern architectural best practice is to loosely couple these services by allowing them to specify their own dependencies, but this can be complicated in dynamic environments as your individual services are forced to find their own connection points.

Traditional approaches to service discovery like consul, etcd, or zookeeper all solve this problem well, but they require provisioning and maintaining additional infrastructure or installation of agents in your containers or on your instances. Previously, to ensure that services were able to discover and connect with each other, you had to configure and run your own service discovery system or connect every service to a load balancer. Now, you can enable service discovery for your containerized services in the ECS console, AWS CLI, or using the ECS API.

Introducing Amazon Route 53 Service Registry and Auto Naming APIs

Amazon ECS Service Discovery works by communicating with the Amazon Route 53 Service Registry and Auto Naming APIs. Since we haven’t talked about it before on this blog, I want to briefly outline how these Route 53 APIs work. First, some vocabulary:

  • Namespaces – A namespace specifies a domain name you want to route traffic to (e.g. internal, local, corp). You can think of it as a logical boundary between which services should be able to discover each other. You can create a namespace with a call to the aws servicediscovery create-private-dns-namespace command or in the ECS console. Namespaces are roughly equivalent to hosted zones in Route 53. A namespace contains services, our next vocabulary word.
  • Service – A service is a specific application or set of applications in your namespace like “auth”, “timeline”, or “worker”. A service contains service instances.
  • Service Instance – A service instance contains information about how Route 53 should respond to DNS queries for a resource.

Route 53 provides APIs to create: namespaces, A records per task IP, and SRV records per task IP + port.

When we ask Route 53 for something like: worker.corp we should get back a set of possible IPs that could fulfill that request. If the application we’re connecting to exposes dynamic ports then the calling application can easily query the SRV record to get more information.

ECS service discovery is built on top of the Route 53 APIs and manages all of the underlying API calls for you. Now that we understand how the service registry, works lets take a look at the ECS side to see service discovery in action.

Amazon ECS Service Discovery

Let’s launch an application with service discovery! First, I’ll create two task definitions: “flask-backend” and “flask-worker”. Both are simple AWS Fargate tasks with a single container serving HTTP requests. I’ll have flask-backend ask worker.corp to do some work and I’ll return the response as well as the address Route 53 returned for worker. Something like the code below:

@app.route("/")
namespace = os.getenv("namespace")
worker_host = "worker" + namespace
def backend():
    r = requests.get("http://"+worker_host)
    worker = socket.gethostbyname(worker_host)
    return "Worker Message: {]\nFrom: {}".format(r.content, worker)

 

Now, with my containers and task definitions in place, I’ll create a service in the console.

As I move to step two in the service wizard I’ll fill out the service discovery section and have ECS create a new namespace for me.

I’ll also tell ECS to monitor the health of the tasks in my service and add or remove them from Route 53 as needed. Then I’ll set a TTL of 10 seconds on the A records we’ll use.

I’ll repeat those same steps for my “worker” service and after a minute or so most of my tasks should be up and running.

Over in the Route 53 console I can see all the records for my tasks!

We can use the Route 53 service discovery APIs to list all of our available services and tasks and programmatically reach out to each one. We could easily extend to any number of services past just backend and worker. I’ve created a simple demo of an imaginary social network with services like “auth”, “feed”, “timeline”, “worker”, “user” and more here: https://servicediscovery.ranman.com/. You can see the code used to run that page on github.

Available Now
Amazon ECS service discovery is available now in US East (N. Virginia), US East (Ohio), US West (Oregon), and EU (Ireland). AWS Fargate is currently only available in US East (N. Virginia). When you use ECS service discovery, you pay for the Route 53 resources that you consume, including each namespace that you create, and for the lookup queries your services make. Container level health checks are provided at no cost. For more information on pricing check out the documentation.

Please let us know what you’ll be building or refactoring with service discovery either in the comments or on Twitter!

Randall

 

P.S. Every blog post I write is made with a tremendous amount of help from numerous AWS colleagues. To everyone that helped build service discovery across all of our teams – thank you :)!

[$] Read-only dynamic data

Post Syndicated from corbet original https://lwn.net/Articles/750215/rss

Kernel developers go to some lengths to mark read-only data so that it can
be protected by the system’s memory-management unit.
Memory that cannot be changed cannot be altered by an attacker to corrupt the
system. But the kernel’s mechanisms for managing read-only memory do not
work for memory that must be initialized after the initial system bootstrap
has completed. A patch set from Igor Stoppa
seeks to change that situation by creating a new API just for
late-initialized read-only data.

New – Amazon DynamoDB Continuous Backups and Point-In-Time Recovery (PITR)

Post Syndicated from Randall Hunt original https://aws.amazon.com/blogs/aws/new-amazon-dynamodb-continuous-backups-and-point-in-time-recovery-pitr/

The Amazon DynamoDB team is back with another useful feature hot on the heels of encryption at rest. At AWS re:Invent 2017 we launched global tables and on-demand backup and restore of your DynamoDB tables and today we’re launching continuous backups with point-in-time recovery (PITR).

You can enable continuous backups with a single click in the AWS Management Console, a simple API call, or with the AWS Command Line Interface (CLI). DynamoDB can back up your data with per-second granularity and restore to any single second from the time PITR was enabled up to the prior 35 days. We built this feature to protect against accidental writes or deletes. If a developer runs a script against production instead of staging or if someone fat-fingers a DeleteItem call, PITR has you covered. We also built it for the scenarios you can’t normally predict. You can still keep your on-demand backups for as long as needed for archival purposes but PITR works as additional insurance against accidental loss of data. Let’s see how this works.

Continuous Backup

To enable this feature in the console we navigate to our table and select the Backups tab. From there simply click Enable to turn on the feature. I could also turn on continuous backups via the UpdateContinuousBackups API call.

After continuous backup is enabled we should be able to see an Earliest restore date and Latest restore date

Let’s imagine a scenario where I have a lot of old user profiles that I want to delete.

I really only want to send service updates to our active users based on their last_update date. I decided to write a quick Python script to delete all the users that haven’t used my service in a while.

import boto3
table = boto3.resource("dynamodb").Table("VerySuperImportantTable")
items = table.scan(
    FilterExpression="last_update >= :date",
    ExpressionAttributeValues={":date": "2014-01-01T00:00:00"},
    ProjectionExpression="ImportantId"
)['Items']
print("Deleting {} Items! Dangerous.".format(len(items)))
with table.batch_writer() as batch:
    for item in items:
        batch.delete_item(Key=item)

Great! This should delete all those pesky non-users of my service that haven’t logged in since 2013. So,— CTRL+C CTRL+C CTRL+C CTRL+C (interrupt the currently executing command).

Yikes! Do you see where I went wrong? I’ve just deleted my most important users! Oh, no! Where I had a greater-than sign, I meant to put a less-than! Quick, before Jeff Barr can see, I’m going to restore the table. (I probably could have prevented that typo with Boto 3’s handy DynamoDB conditions: Attr("last_update").lt("2014-01-01T00:00:00"))

Restoring

Luckily for me, restoring a table is easy. In the console I’ll navigate to the Backups tab for my table and click Restore to point-in-time.

I’ll specify the time (a few seconds before I started my deleting spree) and a name for the table I’m restoring to.

For a relatively small and evenly distributed table like mine, the restore is quite fast.

The time it takes to restore a table varies based on multiple factors and restore times are not neccesarily coordinated with the size of the table. If your dataset is evenly distributed across your primary keys you’ll be able to take advanatage of parallelization which will speed up your restores.

Learn More & Try It Yourself
There’s plenty more to learn about this new feature in the documentation here.

Pricing for continuous backups varies by region and is based on the current size of the table and all indexes.

A few things to note:

  • PITR works with encrypted tables.
  • If you disable PITR and later reenable it, you reset the start time from which you can recover.
  • Just like on-demand backups, there are no performance or availability impacts to enabling this feature.
  • Stream settings, Time To Live settings, PITR settings, tags, Amazon CloudWatch alarms, and auto scaling policies are not copied to the restored table.
  • Jeff, it turns out, knew I restored the table all along because every PITR API call is recorded in AWS CloudTrail.

Let us know how you’re going to use continuous backups and PITR on Twitter and in the comments.
Randall