Tag Archives: space

Use Slack ChatOps to Deploy Your Code – How to Integrate Your Pipeline in AWS CodePipeline with Your Slack Channel

Post Syndicated from Rumi Olsen original https://aws.amazon.com/blogs/devops/use-slack-chatops-to-deploy-your-code-how-to-integrate-your-pipeline-in-aws-codepipeline-with-your-slack-channel/

Slack is widely used by DevOps and development teams to communicate status. Typically, when a build has been tested and is ready to be promoted to a staging environment, a QA engineer or DevOps engineer kicks off the deployment. Using Slack in a ChatOps collaboration model, the promotion can be done in a single click from a Slack channel. And because the promotion happens through a Slack channel, the whole development team knows what’s happening without checking email.

In this blog post, I will show you how to integrate AWS services with a Slack application. I use an interactive message button and incoming webhook to promote a stage with a single click.

To follow along with the steps in this post, you’ll need a pipeline in AWS CodePipeline. If you don’t have a pipeline, the fastest way to create one for this use case is to use AWS CodeStar. Go to the AWS CodeStar console and select the Static Website template (shown in the screenshot). AWS CodeStar will create a pipeline with an AWS CodeCommit repository and an AWS CodeDeploy deployment for you. After the pipeline is created, you will need to add a manual approval stage.

You’ll also need to build a Slack app with webhooks and interactive components, write two Lambda functions, and create an API Gateway API and a SNS topic.

As you’ll see in the following diagram, when I make a change and merge a new feature into the master branch in AWS CodeCommit, the check-in kicks off my CI/CD pipeline in AWS CodePipeline. When CodePipeline reaches the approval stage, it sends a notification to Amazon SNS, which triggers an AWS Lambda function (ApprovalRequester).

The Slack channel receives a prompt that looks like the following screenshot. When I click Yes to approve the build promotion, the approval result is sent to CodePipeline through API Gateway and Lambda (ApprovalHandler). The pipeline continues on to deploy the build to the next environment.

Create a Slack app

For App Name, type a name for your app. For Development Slack Workspace, choose the name of your workspace. You’ll see in the following screenshot that my workspace is AWS ChatOps.

After the Slack application has been created, you will see the Basic Information page, where you can create incoming webhooks and enable interactive components.

To add incoming webhooks:

  1. Under Add features and functionality, choose Incoming Webhooks. Turn the feature on by selecting Off, as shown in the following screenshot.
  2. Now that the feature is turned on, choose Add New Webhook to Workspace. In the process of creating the webhook, Slack lets you choose the channel where messages will be posted.
  3. After the webhook has been created, you’ll see its URL. You will use this URL when you create the Lambda function.

If you followed the steps in the post, the pipeline should look like the following.

Write the Lambda function for approval requests

This Lambda function is invoked by the SNS notification. It sends a request that consists of an interactive message button to the incoming webhook you created earlier.  The following sample code sends the request to the incoming webhook. WEBHOOK_URL and SLACK_CHANNEL are the environment variables that hold values of the webhook URL that you created and the Slack channel where you want the interactive message button to appear.

# This function is invoked via SNS when the CodePipeline manual approval action starts.
# It will take the details from this approval notification and sent an interactive message to Slack that allows users to approve or cancel the deployment.

import os
import json
import logging
import urllib.parse

from base64 import b64decode
from urllib.request import Request, urlopen
from urllib.error import URLError, HTTPError

# This is passed as a plain-text environment variable for ease of demonstration.
# Consider encrypting the value with KMS or use an encrypted parameter in Parameter Store for production deployments.

logger = logging.getLogger()

def lambda_handler(event, context):
    print("Received event: " + json.dumps(event, indent=2))
    message = event["Records"][0]["Sns"]["Message"]
    data = json.loads(message) 
    token = data["approval"]["token"]
    codepipeline_name = data["approval"]["pipelineName"]
    slack_message = {
        "channel": SLACK_CHANNEL,
        "text": "Would you like to promote the build to production?",
        "attachments": [
                "text": "Yes to deploy your build to production",
                "fallback": "You are unable to promote a build",
                "callback_id": "wopr_game",
                "color": "#3AA3E3",
                "attachment_type": "default",
                "actions": [
                        "name": "deployment",
                        "text": "Yes",
                        "style": "danger",
                        "type": "button",
                        "value": json.dumps({"approve": True, "codePipelineToken": token, "codePipelineName": codepipeline_name}),
                        "confirm": {
                            "title": "Are you sure?",
                            "text": "This will deploy the build to production",
                            "ok_text": "Yes",
                            "dismiss_text": "No"
                        "name": "deployment",
                        "text": "No",
                        "type": "button",
                        "value": json.dumps({"approve": False, "codePipelineToken": token, "codePipelineName": codepipeline_name})

    req = Request(SLACK_WEBHOOK_URL, json.dumps(slack_message).encode('utf-8'))

    response = urlopen(req)
    return None


Create a SNS topic

Create a topic and then create a subscription that invokes the ApprovalRequester Lambda function. You can configure the manual approval action in the pipeline to send a message to this SNS topic when an approval action is required. When the pipeline reaches the approval stage, it sends a notification to this SNS topic. SNS publishes a notification to all of the subscribed endpoints. In this case, the Lambda function is the endpoint. Therefore, it invokes and executes the Lambda function. For information about how to create a SNS topic, see Create a Topic in the Amazon SNS Developer Guide.

Write the Lambda function for handling the interactive message button

This Lambda function is invoked by API Gateway. It receives the result of the interactive message button whether or not the build promotion was approved. If approved, an API call is made to CodePipeline to promote the build to the next environment. If not approved, the pipeline stops and does not move to the next stage.

The Lambda function code might look like the following. SLACK_VERIFICATION_TOKEN is the environment variable that contains your Slack verification token. You can find your verification token under Basic Information on Slack manage app page. When you scroll down, you will see App Credential. Verification token is found under the section.

# This function is triggered via API Gateway when a user acts on the Slack interactive message sent by approval_requester.py.

from urllib.parse import parse_qs
import json
import os
import boto3


#Triggered by API Gateway
#It kicks off a particular CodePipeline project
def lambda_handler(event, context):
	#print("Received event: " + json.dumps(event, indent=2))
	body = parse_qs(event['body'])
	payload = json.loads(body['payload'][0])

	# Validate Slack token
	if SLACK_VERIFICATION_TOKEN == payload['token']:
		# This will replace the interactive message with a simple text response.
		# You can implement a more complex message update if you would like.
		return  {
			"isBase64Encoded": "false",
			"statusCode": 200,
			"body": "{\"text\": \"The approval has been processed\"}"
		return  {
			"isBase64Encoded": "false",
			"statusCode": 403,
			"body": "{\"error\": \"This request does not include a vailid verification token.\"}"

def send_slack_message(action_details):
	codepipeline_status = "Approved" if action_details["approve"] else "Rejected"
	codepipeline_name = action_details["codePipelineName"]
	token = action_details["codePipelineToken"] 

	client = boto3.client('codepipeline')
	response_approval = client.put_approval_result(


Create the API Gateway API

  1. In the Amazon API Gateway console, create a resource called InteractiveMessageHandler.
  2. Create a POST method.
    • For Integration type, choose Lambda Function.
    • Select Use Lambda Proxy integration.
    • From Lambda Region, choose a region.
    • In Lambda Function, type a name for your function.
  3.  Deploy to a stage.

For more information, see Getting Started with Amazon API Gateway in the Amazon API Developer Guide.

Now go back to your Slack application and enable interactive components.

To enable interactive components for the interactive message (Yes) button:

  1. Under Features, choose Interactive Components.
  2. Choose Enable Interactive Components.
  3. Type a request URL in the text box. Use the invoke URL in Amazon API Gateway that will be called when the approval button is clicked.

Now that all the pieces have been created, run the solution by checking in a code change to your CodeCommit repo. That will release the change through CodePipeline. When the CodePipeline comes to the approval stage, it will prompt to your Slack channel to see if you want to promote the build to your staging or production environment. Choose Yes and then see if your change was deployed to the environment.


That is it! You have now created a Slack ChatOps solution using AWS CodeCommit, AWS CodePipeline, AWS Lambda, Amazon API Gateway, and Amazon Simple Notification Service.

Now that you know how to do this Slack and CodePipeline integration, you can use the same method to interact with other AWS services using API Gateway and Lambda. You can also use Slack’s slash command to initiate an action from a Slack channel, rather than responding in the way demonstrated in this post.

Replacing macOS Server with Synology NAS

Post Syndicated from Roderick Bauer original https://www.backblaze.com/blog/replacing-macos-server-with-synology-nas/

Synology NAS boxes backed up to the cloud

Businesses and organizations that rely on macOS server for essential office and data services are facing some decisions about the future of their IT services.

Apple recently announced that it is deprecating a significant portion of essential network services in macOS Server, as they described in a support statement posted on April 24, 2018, “Prepare for changes to macOS Server.” Apple’s note includes:

macOS Server is changing to focus more on management of computers, devices, and storage on your network. As a result, some changes are coming in how Server works. A number of services will be deprecated, and will be hidden on new installations of an update to macOS Server coming in spring 2018.

The note lists the services that will be removed in a future release of macOS Server, including calendar and contact support, Dynamic Host Configuration Protocol (DHCP), Domain Name Services (DNS), mail, instant messages, virtual private networking (VPN), NetInstall, Web server, and the Wiki.

Apple assures users who have already configured any of the listed services that they will be able to use them in the spring 2018 macOS Server update, but the statement ends with links to a number of alternative services, including hosted services, that macOS Server users should consider as viable replacements to the features it is removing. These alternative services are all FOSS (Free and Open-Source Software).

As difficult as this could be for organizations that use macOS server, this is not unexpected. Apple left the server hardware space back in 2010, when Steve Jobs announced the company was ending its line of Xserve rackmount servers, which were introduced in May, 2002. Since then, macOS Server has hardly been a prominent part of Apple’s product lineup. It’s not just the product itself that has lost some luster, but the entire category of SMB office and business servers, which has been undergoing a gradual change in recent years.

Some might wonder how important the news about macOS Server is, given that macOS Server represents a pretty small share of the server market. macOS Server has been important to design shops, agencies, education users, and small businesses that likely have been on Macs for ages, but it’s not a significant part of the IT infrastructure of larger organizations and businesses.

What Comes After macOS Server?

Lovers of macOS Server don’t have to fear having their Mac minis pried from their cold, dead hands quite yet. Installed services will continue to be available. In the fall of 2018, new installations and upgrades of macOS Server will require users to migrate most services to other software. Since many of the services of macOS Server were already open-source, this means that a change in software might not be required. It does mean more configuration and management required from those who continue with macOS Server, however.

Users can continue with macOS Server if they wish, but many will see the writing on the wall and look for a suitable substitute.

The Times They Are A-Changin’

For many people working in organizations, what is significant about this announcement is how it reflects the move away from the once ubiquitous server-based IT infrastructure. Services that used to be centrally managed and office-based, such as storage, file sharing, communications, and computing, have moved to the cloud.

In selecting the next office IT platforms, there’s an opportunity to move to solutions that reflect and support how people are working and the applications they are using both in the office and remotely. For many, this means including cloud-based services in office automation, backup, and business continuity/disaster recovery planning. This includes Software as a Service, Platform as a Service, and Infrastructure as a Service (Saas, PaaS, IaaS) options.

IT solutions that integrate well with the cloud are worth strong consideration for what comes after a macOS Server-based environment.

Synology NAS as a macOS Server Alternative

One solution that is becoming popular is to replace macOS Server with a device that has the ability to provide important office services, but also bridges the office and cloud environments. Using Network-Attached Storage (NAS) to take up the server slack makes a lot of sense. Many customers are already using NAS for file sharing, local data backup, automatic cloud backup, and other uses. In the case of Synology, their operating system, Synology DiskStation Manager (DSM), is Linux based, and integrates the basic functions of file sharing, centralized backup, RAID storage, multimedia streaming, virtual storage, and other common functions.

Synology NAS box

Synology NAS

Since DSM is based on Linux, there are numerous server applications available, including many of the same ones that are available for macOS Server, which shares conceptual roots with Linux as it comes from BSD Unix.

Synology DiskStation Manager Package Center screenshot

Synology DiskStation Manager Package Center

According to Ed Lukacs, COO at 2FIFTEEN Systems Management in Salt Lake City, their customers have found the move from macOS Server to Synology NAS not only painless, but positive. DSM works seamlessly with macOS and has been faster for their customers, as well. Many of their customers are running Adobe Creative Suite and Google G Suite applications, so a workflow that combines local storage, remote access, and the cloud, is already well known to them. Remote users are supported by Synology’s QuickConnect or VPN.

Business continuity and backup are simplified by the flexible storage capacity of the NAS. Synology has built-in backup to Backblaze B2 Cloud Storage with Synology’s Cloud Sync, as well as a choice of a number of other B2-compatible applications, such as Cloudberry, Comet, and Arq.

Customers have been able to get up and running quickly, with only initial data transfers requiring some time to complete. After that, management of the NAS can be handled in-house or with the support of a Managed Service Provider (MSP).

Are You Sticking with macOS Server or Moving to Another Platform?

If you’re affected by this change in macOS Server, please let us know in the comments how you’re planning to cope. Are you using Synology NAS for server services? Please tell us how that’s working for you.

The post Replacing macOS Server with Synology NAS appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

HackSpace magazine 7: Internet of Everything

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-7-internet-of-everything/

We’re usually averse to buzzwords at HackSpace magazine, but not this month: in issue 7, we’re taking a deep dive into the Internet of Things.HackSpace magazine issue 7 cover

Internet of Things (IoT)

To many people, IoT is a shady term used by companies to sell you something you already own, but this time with WiFi; to us, it’s a way to make our builds smarter, more useful, and more connected. In HackSpace magazine #7, you can join us on a tour of the boards that power IoT projects, marvel at the ways in which other makers are using IoT, and get started with your first IoT project!

Awesome projects

DIY retro computing: this issue, we’re taking our collective hat off to Spencer Owen. He stuck his home-brew computer on Tindie thinking he might make a bit of beer money — now he’s paying the mortgage with his making skills and inviting others to build modules for his machine. And if that tickles your fancy, why not take a crack at our Z80 tutorial? Get out your breadboard, assemble your jumper wires, and prepare to build a real-life computer!

Inside HackSpace magazine issue 7

Shameless patriotism: combine Lego, Arduino, and the car of choice for 1960 gold bullion thieves, and you’ve got yourself a groovy weekend project. We proudly present to you one man’s epic quest to add LED lights (controllable via a smartphone!) to his daughter’s LEGO Mini Cooper.


Patriotism intensifies: for the last 200-odd years, the Black Country has been a hotbed of making. Urban Hax, based in Walsall, is the latest makerspace to show off its riches in the coveted Space of the Month pages. Every space has its own way of doing things, but not every space has a portrait of Rob Halford on the wall. All hail!

Inside HackSpace magazine issue 7

Diversity: advice on diversity often boils down to ‘Be nice to people’, which might feel more vague than actionable. This is where we come in to help: it is truly worth making the effort to give people of all backgrounds access to your makerspace, so we take a look at why it’s nice to be nice, and at the ways in which one makerspace has put niceness into practice — with great results.

And there’s more!

We also show you how to easily calculate the size and radius of laser-cut gears, use a bank of LEDs to etch PCBs in your own mini factory, and use chemistry to mess with your lunch menu.

Inside HackSpace magazine issue 7
Helen Steer inside HackSpace magazine issue 7
Inside HackSpace magazine issue 7

All this plus much, much more waits for you in HackSpace magazine issue 7!

Get your copy of HackSpace magazine

If you like the sound of that, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine.

And if you can’t get to the shops, fear not: you can subscribe from £4 an issue from our online shop. And if you’d rather try before you buy, you can always download the free PDF. Happy reading, and happy making!

The post HackSpace magazine 7: Internet of Everything appeared first on Raspberry Pi.

C is to low level

Post Syndicated from Robert Graham original https://blog.erratasec.com/2018/05/c-is-too-low-level.html

I’m in danger of contradicting myself, after previously pointing out that x86 machine code is a high-level language, but this article claiming C is a not a low level language is bunk. C certainly has some problems, but it’s still the closest language to assembly. This is obvious by the fact it’s still the fastest compiled language. What we see is a typical academic out of touch with the real world.

The author makes the (wrong) observation that we’ve been stuck emulating the PDP-11 for the past 40 years. C was written for the PDP-11, and since then CPUs have been designed to make C run faster. The author imagines a different world, such as where CPU designers instead target something like LISP as their preferred language, or Erlang. This misunderstands the state of the market. CPUs do indeed supports lots of different abstractions, and C has evolved to accommodate this.

The author criticizes things like “out-of-order” execution which has lead to the Spectre sidechannel vulnerabilities. Out-of-order execution is necessary to make C run faster. The author claims instead that those resources should be spent on having more slower CPUs, with more threads. This sacrifices single-threaded performance in exchange for a lot more threads executing in parallel. The author cites Sparc Tx CPUs as his ideal processor.

But here’s the thing, the Sparc Tx was a failure. To be fair, it’s mostly a failure because most of the time, people wanted to run old C code instead of new Erlang code. But it was still a failure at running Erlang.

Time after time, engineers keep finding that “out-of-order”, single-threaded performance is still the winner. A good example is ARM processors for both mobile phones and servers. All the theory points to in-order CPUs as being better, but all the products are out-of-order, because this theory is wrong. The custom ARM cores from Apple and Qualcomm used in most high-end phones are so deeply out-of-order they give Intel CPUs competition. The same is true on the server front with the latest Qualcomm Centriq and Cavium ThunderX2 processors, deeply out of order supporting more than 100 instructions in flight.

The Cavium is especially telling. Its ThunderX CPU had 48 simple cores which was replaced with the ThunderX2 having 32 complex, deeply out-of-order cores. The performance increase was massive, even on multithread-friendly workloads. Every competitor to Intel’s dominance in the server space has learned the lesson from Sparc Tx: many wimpy cores is a failure, you need fewer beefy cores. Yes, they don’t need to be as beefy as Intel’s processors, but they need to be close.

Even Intel’s “Xeon Phi” custom chip learned this lesson. This is their GPU-like chip, running 60 cores with 512-bit wide “vector” (sic) instructions, designed for supercomputer applications. Its first version was purely in-order. Its current version is slightly out-of-order. It supports four threads and focuses on basic number crunching, so in-order cores seems to be the right approach, but Intel found in this case that out-of-order processing still provided a benefit. Practice is different than theory.

As an academic, the author of the above article focuses on abstractions. The criticism of C is that it has the wrong abstractions which are hard to optimize, and that if we instead expressed things in the right abstractions, it would be easier to optimize.

This is an intellectually compelling argument, but so far bunk.

The reason is that while the theoretical base language has issues, everyone programs using extensions to the language, like “intrinsics” (C ‘functions’ that map to assembly instructions). Programmers write libraries using these intrinsics, which then the rest of the normal programmers use. In other words, if your criticism is that C is not itself low level enough, it still provides the best access to low level capabilities.

Given that C can access new functionality in CPUs, CPU designers add new paradigms, from SIMD to transaction processing. In other words, while in the 1980s CPUs were designed to optimize C (stacks, scaled pointers), these days CPUs are designed to optimize tasks regardless of language.

The author of that article criticizes the memory/cache hierarchy, claiming it has problems. Yes, it has problems, but only compared to how well it normally works. The author praises the many simple cores/threads idea as hiding memory latency with little caching, but misses the point that caches also dramatically increase memory bandwidth. Intel processors are optimized to read a whopping 256 bits every clock cycle from L1 cache. Main memory bandwidth is orders of magnitude slower.

The author goes onto criticize cache coherency as a problem. C uses it, but other languages like Erlang don’t need it. But that’s largely due to the problems each languages solves. Erlang solves the problem where a large number of threads work on largely independent tasks, needing to send only small messages to each other across threads. The problems C solves is when you need many threads working on a huge, common set of data.

For example, consider the “intrusion prevention system”. Any thread can process any incoming packet that corresponds to any region of memory. There’s no practical way of solving this problem without a huge coherent cache. It doesn’t matter which language or abstractions you use, it’s the fundamental constraint of the problem being solved. RDMA is an important concept that’s moved from supercomputer applications to the data center, such as with memcached. Again, we have the problem of huge quantities (terabytes worth) shared among threads rather than small quantities (kilobytes).

The fundamental issue the author of the the paper is ignoring is decreasing marginal returns. Moore’s Law has gifted us more transistors than we can usefully use. We can’t apply those additional registers to just one thing, because the useful returns we get diminish.

For example, Intel CPUs have two hardware threads per core. That’s because there are good returns by adding a single additional thread. However, the usefulness of adding a third or fourth thread decreases. That’s why many CPUs have only two threads, or sometimes four threads, but no CPU has 16 threads per core.

You can apply the same discussion to any aspect of the CPU, from register count, to SIMD width, to cache size, to out-of-order depth, and so on. Rather than focusing on one of these things and increasing it to the extreme, CPU designers make each a bit larger every process tick that adds more transistors to the chip.

The same applies to cores. It’s why the “more simpler cores” strategy fails, because more cores have their own decreasing marginal returns. Instead of adding cores tied to limited memory bandwidth, it’s better to add more cache. Such cache already increases the size of the cores, so at some point it’s more effective to add a few out-of-order features to each core rather than more cores. And so on.

The question isn’t whether we can change this paradigm and radically redesign CPUs to match some academic’s view of the perfect abstraction. Instead, the goal is to find new uses for those additional transistors. For example, “message passing” is a useful abstraction in languages like Go and Erlang that’s often more useful than sharing memory. It’s implemented with shared memory and atomic instructions, but I can’t help but think it couldn’t better be done with direct hardware support.

Of course, as soon as they do that, it’ll become an intrinsic in C, then added to languages like Go and Erlang.


Academics live in an ideal world of abstractions, the rest of us live in practical reality. The reality is that vast majority of programmers work with the C family of languages (JavaScript, Go, etc.), whereas academics love the epiphanies they learned using other languages, especially function languages. CPUs are only superficially designed to run C and “PDP-11 compatibility”. Instead, they keep adding features to support other abstractions, abstractions available to C. They are driven by decreasing marginal returns — they would love to add new abstractions to the hardware because it’s a cheap way to make use of additional transitions. Academics are wrong believing that the entire system needs to be redesigned from scratch. Instead, they just need to come up with new abstractions CPU designers can add.

Working with the Scout Association on digital skills for life

Post Syndicated from Philip Colligan original https://www.raspberrypi.org/blog/working-with-scout-association-digital-skills-for-life/

Today we’re launching a new partnership between the Scouts and the Raspberry Pi Foundation that will help tens of thousands of young people learn crucial digital skills for life. In this blog post, I want to explain what we’ve got planned, why it matters, and how you can get involved.

This is personal

First, let me tell you why this partnership matters to me. As a child growing up in North Wales in the 1980s, Scouting changed my life. My time with 2nd Rhyl provided me with countless opportunities to grow and develop new skills. It taught me about teamwork and community in ways that continue to shape my decisions today.

As my own kids (now seven and ten) have joined Scouting, I’ve seen the same opportunities opening up for them, and like so many parents, I’ve come back to the movement as a volunteer to support their local section. So this is deeply personal for me, and the same is true for many of my colleagues at the Raspberry Pi Foundation who in different ways have been part of the Scouting movement.

That shouldn’t come as a surprise. Scouting and Raspberry Pi share many of the same values. We are both community-led movements that aim to help young people develop the skills they need for life. We are both powered by an amazing army of volunteers who give their time to support that mission. We both care about inclusiveness, and pride ourselves on combining fun with learning by doing.

Raspberry Pi

Raspberry Pi started life in 2008 as a response to the problem that too many young people were growing up without the skills to create with technology. Our goal is that everyone should be able to harness the power of computing and digital technologies, for work, to solve problems that matter to them, and to express themselves creatively.

In 2012 we launched our first product, the world’s first $35 computer. Just six years on, we have sold over 20 million Raspberry Pi computers and helped kickstart a global movement for digital skills.

The Raspberry Pi Foundation now runs the world’s largest network of volunteer-led computing clubs (Code Clubs and CoderDojos), and creates free educational resources that are used by millions of young people all over the world to learn how to create with digital technologies. And lots of what we are able to achieve is because of partnerships with fantastic organisations that share our goals. For example, through our partnership with the European Space Agency, thousands of young people have written code that has run on two Raspberry Pi computers that Tim Peake took to the International Space Station as part of his Mission Principia.

Digital makers

Today we’re launching the new Digital Maker Staged Activity Badge to help tens of thousands of young people learn how to create with technology through Scouting. Over the past few months, we’ve been working with the Scouts all over the UK to develop and test the new badge requirements, along with guidance, project ideas, and resources that really make them work for Scouting. We know that we need to get two things right: relevance and accessibility.

Relevance is all about making sure that the activities and resources we provide are a really good fit for Scouting and Scouting’s mission to equip young people with skills for life. From the digital compass to nature cameras and the reinvented wide game, we’ve had a lot of fun thinking about ways we can bring to life the crucial role that digital technologies can play in the outdoors and adventure.

Compass Coding with Raspberry Pi

We are beyond excited to be launching a new partnership with the Raspberry Pi Foundation, which will help tens of thousands of young people learn digital skills for life.

We also know that there are great opportunities for Scouts to use digital technologies to solve social problems in their communities, reflecting the movement’s commitment to social action. Today we’re launching the first set of project ideas and resources, with many more to follow over the coming weeks and months.

Accessibility is about providing every Scout leader with the confidence, support, and kit to enable them to offer the Digital Maker Staged Activity Badge to their young people. A lot of work and care has gone into designing activities that require very little equipment: for example, activities at Stages 1 and 2 can be completed with a laptop without access to the internet. For the activities that do require kit, we will be working with Scout Stores and districts to make low-cost kit available to buy or loan.

We’re producing accessible instructions, worksheets, and videos to help leaders run sessions with confidence, and we’ll also be planning training for leaders. We will work with our network of Code Clubs and CoderDojos to connect them with local sections to organise joint activities, bringing both kit and expertise along with them.

Get involved

Today’s launch is just the start. We’ll be developing our partnership over the next few years, and we can’t wait for you to join us in getting more young people making things with technology.

Take a look at the brand-new Raspberry Pi resources designed especially for Scouts, to get young people making and creating right away.

The post Working with the Scout Association on digital skills for life appeared first on Raspberry Pi.

All Systems Go! 2018 CfP Open

Post Syndicated from Lennart Poettering original http://0pointer.net/blog/all-systems-go-2018-cfp-open.html

The All Systems Go! 2018 Call for Participation is Now Open!

The Call for Participation (CFP) for All Systems Go!
is now open. We’d like to invite you
to submit your proposals for consideration to the CFP submission

ASG image

The CFP will close on July 30th. Notification of acceptance and
non-acceptance will go out within 7 days of the closing of the CFP.

All topics relevant to foundational open-source Linux technologies are
welcome. In particular, however, we are looking for proposals
including, but not limited to, the following topics:

  • Low-level container executors and infrastructure
  • IoT and embedded OS infrastructure
  • BPF and eBPF filtering
  • OS, container, IoT image delivery and updating
  • Building Linux devices and applications
  • Low-level desktop technologies
  • Networking
  • System and service management
  • Tracing and performance measuring
  • IPC and RPC systems
  • Security and Sandboxing

While our focus is definitely more on the user-space side of things,
talks about kernel projects are welcome, as long as they have a clear
and direct relevance for user-space.

For more information please visit our conference

[$] The NOVA filesystem

Post Syndicated from jake original https://lwn.net/Articles/754505/rss

At the 2018 Linux Storage, Filesystem, and Memory-Management Summit, Andiry
Xu presented the NOVA filesystem, which he
is trying to get into the upstream kernel. Unlike existing kernel
filesystems, NOVA exclusively targets non-volatile main memory (NVMM)
rather than
traditional block devices (disks or SSDs). In fact, it does not use the
kernel’s block layer at all and instead uses persistent memory mapped
directly into the kernel address space.

Connect Veeam to the B2 Cloud: Episode 3 — Using OpenDedup

Post Syndicated from Roderick Bauer original https://www.backblaze.com/blog/opendedup-for-cloud-storage/

Veeam backup to Backblaze B2 logo

In this, the third post in our series on connecting Veeam with Backblaze B2 Cloud Storage, we discuss how to back up your VMs to B2 using Veeam and OpenDedup. In our previous posts, we covered how to connect Veeam to the B2 cloud using Synology, and how to connect Veeam with B2 using StarWind VTL.

Deduplication and OpenDedup

Deduplication is simply the process of eliminating redundant data on disk. Deduplication reduces storage space requirements, improves backup speed, and lowers backup storage costs. The dedup field used to be dominated by a few big-name vendors who sold dedup systems that were too expensive for most of the SMB market. Then an open-source challenger came along in OpenDedup, a project that produced the Space Deduplication File System (SDFS). SDFS provides many of the features of commercial dedup products without their cost.

OpenDedup provides inline deduplication that can be used with applications such as Veeam, Veritas Backup Exec, and Veritas NetBackup.

Features Supported by OpenDedup:

  • Variable Block Deduplication to cloud storage
  • Local Data Caching
  • Encryption
  • Bandwidth Throttling
  • Fast Cloud Recovery
  • Windows and Linux Support

Why use Veeam with OpenDedup to Backblaze B2?

With your VMs backed up to B2, you have a number of options to recover from a disaster. If the unexpected occurs, you can quickly restore your VMs from B2 to the location of your choosing. You also have the option to bring up cloud compute through B2’s compute partners, thereby minimizing any loss of service and ensuring business continuity.

Veeam logo  +  OpenDedup logo  +  Backblaze B2 logo

Backblaze’s B2 is an ideal solution for backing up Veeam’s backup repository due to B2’s combination of low-cost and high availability. Users of B2 save up to 75% compared to other cloud solutions such as Microsoft Azure, Amazon AWS, or Google Cloud Storage. When combined with OpenDedup’s no-cost deduplication, you’re got an efficient and economical solution for backing up VMs to the cloud.

How to Use OpenDedup with B2

For step-by-step instructions for how to set up OpenDedup for use with B2 on Windows or Linux, see Backblaze B2 Enabled on the OpenDedup website.

Are you backing up Veeam to B2 using one of the solutions we’ve written about in this series? If you have, we’d love to hear from you in the comments.

View all posts in the Veeam series.

The post Connect Veeam to the B2 Cloud: Episode 3 — Using OpenDedup appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Puerto Rico’s First Raspberry Pi Educator Workshop

Post Syndicated from Dana Augustin original https://www.raspberrypi.org/blog/puerto-rico-raspberry-pi-workshop/

Earlier this spring, an excited group of STEM educators came together to participate in the first ever Raspberry Pi and Arduino workshop in Puerto Rico.

Their three-day digital making adventure was led by MakerTechPR’s José Rullán and Raspberry Pi Certified Educator Alex Martínez. They ran the event as part of the Robot Makers challenge organized by Yees! and sponsored by Puerto Rico’s Department of Economic Development and Trade to promote entrepreneurial skills within Puerto Rico’s education system.

Over 30 educators attended the workshop, which covered the use of the Raspberry Pi 3 as a computer and digital making resource. The educators received a kit consisting of a Raspberry Pi 3 with an Explorer HAT Pro and an Arduino Uno. At the end of the workshop, the educators were able to keep the kit as a demonstration unit for their classrooms. They were enthusiastic to learn new concepts and immerse themselves in the world of physical computing.

In their first session, the educators were introduced to the Raspberry Pi as an affordable technology for robotic clubs. In their second session, they explored physical computing and the coding languages needed to control the Explorer HAT Pro. They started off coding with Scratch, with which some educators had experience, and ended with controlling the GPIO pins with Python. In the final session, they learned how to develop applications using the powerful combination of Arduino and Raspberry Pi for robotics projects. This gave them a better understanding of how they could engage their students in physical computing.

“The Raspberry Pi ecosystem is the perfect solution in the classroom because to us it is very resourceful and accessible.” – Alex Martínez

Computer science and robotics courses are important for many schools and teachers in Puerto Rico. The simple idea of programming a microcontroller from a $35 computer increases the chances of more students having access to more technology to create things.

Puerto Rico’s education system has faced enormous challenges after Hurricane Maria, including economic collapse and the government’s closure of many schools due to the exodus of families from the island. By attending training like this workshop, educators in Puerto Rico are becoming more experienced in fields like robotics in particular, which are key for 21st-century skills and learning. This, in turn, can lead to more educational opportunities, and hopefully the reopening of more schools on the island.

“We find it imperative that our children be taught STEM disciplines and skills. Our goal is to continue this work of spreading digital making and computer science using the Raspberry Pi around Puerto Rico. We want our children to have the best education possible.” – Alex Martínez

After attending Picademy in 2016, Alex has integrated the Raspberry Pi Foundation’s online resources into his classroom. He has also taught small workshops around the island and in the local Puerto Rican makerspace community. José is an electrical engineer, entrepreneur, educator and hobbyist who enjoys learning to use technology and sharing his knowledge through projects and challenges.

The post Puerto Rico’s First Raspberry Pi Educator Workshop appeared first on Raspberry Pi.

[$] Using user-space tracepoints with BPF

Post Syndicated from corbet original https://lwn.net/Articles/753601/rss

Much has been written on LWN about dynamically instrumenting kernel
code. These features are also available to user-space code with a
special kind of probe known as a User Statically-Defined Tracing
(USDT) probe. These probes provide a low-overhead way of
instrumenting user-space code and provide a convenient way to debug applications
running in production. In this final article of the BPF and BCC series
we’ll look at where USDT probes come from and how you can use them to
understand the behavior of your own applications.

Augmented-reality projection lamp with Raspberry Pi and Android Things

Post Syndicated from Helen Lynn original https://www.raspberrypi.org/blog/augmented-reality-projector/

If your day has been a little fraught so far, watch this video. It opens with a tableau of methodically laid-out components and then shows them soldered, screwed, and slotted neatly into place. Everything fits perfectly; nothing needs percussive adjustment. Then it shows us glimpses of an AR future just like the one promised in the less dystopian comics and TV programmes of my 1980s childhood. It is all very soothing, and exactly what I needed.

Android Things – Lantern

Transform any surface into mixed-reality using Raspberry Pi, a laser projector, and Android Things. Android Experiments – http://experiments.withgoogle.com/android/lantern Lantern project site – http://nordprojects.co/lantern check below to make your own ↓↓↓ Get the code – https://github.com/nordprojects/lantern Build the lamp – https://www.hackster.io/nord-projects/lantern-9f0c28

Creating augmented reality with projection

We’ve seen plenty of Raspberry Pi IoT builds that are smart devices for the home; they add computing power to things like lights, door locks, or toasters to make these objects interact with humans and with their environment in new ways. Nord ProjectsLantern takes a different approach. In their words, it:

imagines a future where projections are used to present ambient information, and relevant UI within everyday objects. Point it at a clock to show your appointments, or point to speaker to display the currently playing song. Unlike a screen, when Lantern’s projections are no longer needed, they simply fade away.

Lantern is set up so that you can connect your wireless device to it using Google Nearby. This means there’s no need to create an account before you can dive into augmented reality.

Lantern Raspberry Pi powered projector lamp

Your own open-source AR lamp

Nord Projects collaborated on Lantern with Google’s Android Things team. They’ve made it fully open-source, so you can find the code on GitHub and also download their parts list, which includes a Pi, an IKEA lamp, an accelerometer, and a laser projector. Build instructions are at hackster.io and on GitHub.

This is a particularly clear tutorial, very well illustrated with photos and GIFs, and once you’ve sourced and 3D-printed all of the components, you shouldn’t need a whole lot of experience to put everything together successfully. Since everything is open-source, though, if you want to adapt it — for example, if you’d like to source a less costly projector than the snazzy one used here — you can do that too.

components of Lantern Raspberry Pi powered augmented reality projector lamp

The instructions walk you through the mechanical build and the wiring, as well as installing Android Things and Nord Projects’ custom software on the Raspberry Pi. Once you’ve set everything up, an accelerometer connected to the Pi’s GPIO pins lets the lamp know which surface it is pointing at. A companion app on your mobile device lets you choose from the mini apps that work on that surface to select the projection you want.

The designers are making several mini apps available for Lantern, including the charmingly named Space Porthole: this uses Processing and your local longitude and latitude to project onto your ceiling the stars you’d see if you punched a hole through to the sky, if it were night time, and clear weather. Wouldn’t you rather look at that than deal with the ant problem in your kitchen or tackle your GitHub notifications?

What would you like to project onto your living environment? Let us know in the comments!

The post Augmented-reality projection lamp with Raspberry Pi and Android Things appeared first on Raspberry Pi.

AWS Online Tech Talks – May and Early June 2018

Post Syndicated from Devin Watson original https://aws.amazon.com/blogs/aws/aws-online-tech-talks-may-and-early-june-2018/

AWS Online Tech Talks – May and Early June 2018  

Join us this month to learn about some of the exciting new services and solution best practices at AWS. We also have our first re:Invent 2018 webinar series, “How to re:Invent”. Sign up now to learn more, we look forward to seeing you.

Note – All sessions are free and in Pacific Time.

Tech talks featured this month:

Analytics & Big Data

May 21, 2018 | 11:00 AM – 11:45 AM PT Integrating Amazon Elasticsearch with your DevOps Tooling – Learn how you can easily integrate Amazon Elasticsearch Service into your DevOps tooling and gain valuable insight from your log data.

May 23, 2018 | 11:00 AM – 11:45 AM PTData Warehousing and Data Lake Analytics, Together – Learn how to query data across your data warehouse and data lake without moving data.

May 24, 2018 | 11:00 AM – 11:45 AM PTData Transformation Patterns in AWS – Discover how to perform common data transformations on the AWS Data Lake.


May 29, 2018 | 01:00 PM – 01:45 PM PT – Creating and Managing a WordPress Website with Amazon Lightsail – Learn about Amazon Lightsail and how you can create, run and manage your WordPress websites with Amazon’s simple compute platform.

May 30, 2018 | 01:00 PM – 01:45 PM PTAccelerating Life Sciences with HPC on AWS – Learn how you can accelerate your Life Sciences research workloads by harnessing the power of high performance computing on AWS.


May 24, 2018 | 01:00 PM – 01:45 PM PT – Building Microservices with the 12 Factor App Pattern on AWS – Learn best practices for building containerized microservices on AWS, and how traditional software design patterns evolve in the context of containers.


May 21, 2018 | 01:00 PM – 01:45 PM PTHow to Migrate from Cassandra to Amazon DynamoDB – Get the benefits, best practices and guides on how to migrate your Cassandra databases to Amazon DynamoDB.

May 23, 2018 | 01:00 PM – 01:45 PM PT5 Hacks for Optimizing MySQL in the Cloud – Learn how to optimize your MySQL databases for high availability, performance, and disaster resilience using RDS.


May 23, 2018 | 09:00 AM – 09:45 AM PT.NET Serverless Development on AWS – Learn how to build a modern serverless application in .NET Core 2.0.

Enterprise & Hybrid

May 22, 2018 | 11:00 AM – 11:45 AM PTHybrid Cloud Customer Use Cases on AWS – Learn how customers are leveraging AWS hybrid cloud capabilities to easily extend their datacenter capacity, deliver new services and applications, and ensure business continuity and disaster recovery.


May 31, 2018 | 11:00 AM – 11:45 AM PTUsing AWS IoT for Industrial Applications – Discover how you can quickly onboard your fleet of connected devices, keep them secure, and build predictive analytics with AWS IoT.

Machine Learning

May 22, 2018 | 09:00 AM – 09:45 AM PTUsing Apache Spark with Amazon SageMaker – Discover how to use Apache Spark with Amazon SageMaker for training jobs and application integration.

May 24, 2018 | 09:00 AM – 09:45 AM PTIntroducing AWS DeepLens – Learn how AWS DeepLens provides a new way for developers to learn machine learning by pairing the physical device with a broad set of tutorials, examples, source code, and integration with familiar AWS services.

Management Tools

May 21, 2018 | 09:00 AM – 09:45 AM PTGaining Better Observability of Your VMs with Amazon CloudWatch – Learn how CloudWatch Agent makes it easy for customers like Rackspace to monitor their VMs.


May 29, 2018 | 11:00 AM – 11:45 AM PT – Deep Dive on Amazon Pinpoint Segmentation and Endpoint Management – See how segmentation and endpoint management with Amazon Pinpoint can help you target the right audience.


May 31, 2018 | 09:00 AM – 09:45 AM PTMaking Private Connectivity the New Norm via AWS PrivateLink – See how PrivateLink enables service owners to offer private endpoints to customers outside their company.

Security, Identity, & Compliance

May 30, 2018 | 09:00 AM – 09:45 AM PT – Introducing AWS Certificate Manager Private Certificate Authority (CA) – Learn how AWS Certificate Manager (ACM) Private Certificate Authority (CA), a managed private CA service, helps you easily and securely manage the lifecycle of your private certificates.

June 1, 2018 | 09:00 AM – 09:45 AM PTIntroducing AWS Firewall Manager – Centrally configure and manage AWS WAF rules across your accounts and applications.


May 22, 2018 | 01:00 PM – 01:45 PM PTBuilding API-Driven Microservices with Amazon API Gateway – Learn how to build a secure, scalable API for your application in our tech talk about API-driven microservices.


May 30, 2018 | 11:00 AM – 11:45 AM PTAccelerate Productivity by Computing at the Edge – Learn how AWS Snowball Edge support for compute instances helps accelerate data transfers, execute custom applications, and reduce overall storage costs.

June 1, 2018 | 11:00 AM – 11:45 AM PTLearn to Build a Cloud-Scale Website Powered by Amazon EFS – Technical deep dive where you’ll learn tips and tricks for integrating WordPress, Drupal and Magento with Amazon EFS.





This is a really lovely Raspberry Pi tricorder

Post Syndicated from Helen Lynn original https://www.raspberrypi.org/blog/raspberry-pi-tricorder-prop/

At the moment I’m spending my evenings watching all of Star Trek in order. Yes, I have watched it before (but with some really big gaps). Yes, including the animated series (I’m up to The Terratin Incident). So I’m gratified to find this beautiful The Original Series–style tricorder build.

Star Trek Tricorder with Working Display!

At this year’s Replica Prop Forum showcase, we meet up once again wtih Brian Mix, who brought his new Star Trek TOS Tricorder. This beautiful replica captures the weight and finish of the filming hand prop, and Brian has taken it one step further with some modern-day electronics!

A what now?

If you don’t know what a tricorder is, which I guess is faintly possible, the easiest way I can explain is to steal words that Liz wrote when Recantha made one back in 2013. It’s “a made-up thing used by the crew of the Enterprise to measure stuff, store data, and scout ahead remotely when exploring strange new worlds, seeking out new life and new civilisations, and all that jazz.”

A brief history of Picorders

We’ve seen other Raspberry Pi–based realisations of this iconic device. Recantha’s LEGO-cased tricorder delivered some authentic functionality, including temperature sensors, an ultrasonic distance sensor, a photosensor, and a magnetometer. Michael Hahn’s tricorder for element14’s Sci-Fi Your Pi competition in 2015 packed some similar functions, along with Original Series audio effects, into a neat (albeit non-canon) enclosure.

Brian Mix’s Original Series tricorder

Brian Mix’s tricorder, seen in the video above from Tested at this year’s Replica Prop Forum showcase, is based on a high-quality kit into which, he discovered, a Raspberry Pi just fits. He explains that the kit is the work of the late Steve Horch, a special effects professional who provided props for later Star Trek series, including the classic Deep Space Nine episode Trials and Tribble-ations.

A still from an episode of Star Trek: Deep Space Nine: Jadzia Dax, holding an Original Series-sylte tricorder, speaks with Benjamin Sisko

Dax, equipped for time travel

This episode’s plot required sets and props — including tricorders — replicating the USS Enterprise of The Original Series, and Steve Horch provided many of these. Thus, a tricorder kit from him is about as close to authentic as you can possibly find unless you can get your hands on a screen-used prop. The Pi allows Brian to drive a real display and a speaker: “Being the geek that I am,” he explains, “I set it up to run every single Original Series Star Trek episode.”

Even more wonderful hypothetical tricorders that I would like someone to make

This tricorder is beautiful, and it makes me think how amazing it would be to squeeze in some of the sensor functionality of the devices depicted in the show. Space in the case is tight, but it looks like there might be a little bit of depth to spare — enough for an IMU, maybe, or a temperature sensor. I’m certain the future will bring more Pi tricorder builds, and I, for one, can’t wait. Please tell us in the comments if you’re planning something along these lines, and, well, I suppose some other sci-fi franchises have decent Pi project potential too, so we could probably stand to hear about those.

If you’re commenting, no spoilers please past The Animated Series S1 E11. Thanks.

The post This is a really lovely Raspberry Pi tricorder appeared first on Raspberry Pi.

[$] A mapping layer for filesystems

Post Syndicated from jake original https://lwn.net/Articles/753650/rss

In a plenary session on the second day of the Linux Storage, Filesystem,
and Memory-Management Summit (LSFMM), Dave Chinner described his ideas for
a virtual block address-space layer. It would allow “space accounting to be
shared and managed at various layers in the storage stack”. One of the
targets for this work is for filesystems on thin-provisioned devices, where
the filesystem
is larger than the storage devices holding it (and administrators are
expected to add storage as needed); in current systems, running out of
space causes huge problems for filesystems and users because the filesystem
cannot communicate that error in a usable fashion.

Cryptocurrency Security Challenges

Post Syndicated from Roderick Bauer original https://www.backblaze.com/blog/cryptocurrency-security-challenges/

Physical coins representing cyrptocurrencies

Most likely you’ve read the tantalizing stories of big gains from investing in cryptocurrencies. Someone who invested $1,000 into bitcoins five years ago would have over $85,000 in value now. Alternatively, someone who invested in bitcoins three months ago would have seen their investment lose 20% in value. Beyond the big price fluctuations, currency holders are possibly exposed to fraud, bad business practices, and even risk losing their holdings altogether if they are careless in keeping track of the all-important currency keys.

It’s certain that beyond the rewards and risks, cryptocurrencies are here to stay. We can’t ignore how they are changing the game for how money is handled between people and businesses.

Some Advantages of Cryptocurrency

  • Cryptocurrency is accessible to anyone.
  • Decentralization means the network operates on a user-to-user (or peer-to-peer) basis.
  • Transactions can completed for a fraction of the expense and time required to complete traditional asset transfers.
  • Transactions are digital and cannot be counterfeited or reversed arbitrarily by the sender, as with credit card charge-backs.
  • There aren’t usually transaction fees for cryptocurrency exchanges.
  • Cryptocurrency allows the cryptocurrency holder to send exactly what information is needed and no more to the merchant or recipient, even permitting anonymous transactions (for good or bad).
  • Cryptocurrency operates at the universal level and hence makes transactions easier internationally.
  • There is no other electronic cash system in which your account isn’t owned by someone else.

On top of all that, blockchain, the underlying technology behind cryptocurrencies, is already being applied to a variety of business needs and itself becoming a hot sector of the tech economy. Blockchain is bringing traceability and cost-effectiveness to supply-chain management — which also improves quality assurance in areas such as food, reducing errors and improving accounting accuracy, smart contracts that can be automatically validated, signed and enforced through a blockchain construct, the possibility of secure, online voting, and many others.

Like any new, booming marketing there are risks involved in these new currencies. Anyone venturing into this domain needs to have their eyes wide open. While the opportunities for making money are real, there are even more ways to lose money.

We’re going to cover two primary approaches to staying safe and avoiding fraud and loss when dealing with cryptocurrencies. The first is to thoroughly vet any person or company you’re dealing with to judge whether they are ethical and likely to succeed in their business segment. The second is keeping your critical cryptocurrency keys safe, which we’ll deal with in this and a subsequent post.

Caveat Emptor — Buyer Beware

The short history of cryptocurrency has already seen the demise of a number of companies that claimed to manage, mine, trade, or otherwise help their customers profit from cryptocurrency. Mt. Gox, GAW Miners, and OneCoin are just three of the many companies that disappeared with their users’ money. This is the traditional equivalent of your bank going out of business and zeroing out your checking account in the process.

That doesn’t happen with banks because of regulatory oversight. But with cryptocurrency, you need to take the time to investigate any company you use to manage or trade your currencies. How long have they been around? Who are their investors? Are they affiliated with any reputable financial institutions? What is the record of their founders and executive management? These are all important questions to consider when evaluating a company in this new space.

Would you give the keys to your house to a service or person you didn’t thoroughly know and trust? Some companies that enable you to buy and sell currencies online will routinely hold your currency keys, which gives them the ability to do anything they want with your holdings, including selling them and pocketing the proceeds if they wish.

That doesn’t mean you shouldn’t ever allow a company to keep your currency keys in escrow. It simply means that you better know with whom you’re doing business and if they’re trustworthy enough to be given that responsibility.

Keys To the Cryptocurrency Kingdom — Public and Private

If you’re an owner of cryptocurrency, you know how this all works. If you’re not, bear with me for a minute while I bring everyone up to speed.

Cryptocurrency has no physical manifestation, such as bills or coins. It exists purely as a computer record. And unlike currencies maintained by governments, such as the U.S. dollar, there is no central authority regulating its distribution and value. Cryptocurrencies use a technology called blockchain, which is a decentralized way of keeping track of transactions. There are many copies of a given blockchain, so no single central authority is needed to validate its authenticity or accuracy.

The validity of each cryptocurrency is determined by a blockchain. A blockchain is a continuously growing list of records, called “blocks”, which are linked and secured using cryptography. Blockchains by design are inherently resistant to modification of the data. They perform as an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable, permanent way. A blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority. On a scaled network, this level of collusion is impossible — making blockchain networks effectively immutable and trustworthy.

Blockchain process

The other element common to all cryptocurrencies is their use of public and private keys, which are stored in the currency’s wallet. A cryptocurrency wallet stores the public and private “keys” or “addresses” that can be used to receive or spend the cryptocurrency. With the private key, it is possible to write in the public ledger (blockchain), effectively spending the associated cryptocurrency. With the public key, it is possible for others to send currency to the wallet.

What is a cryptocurrency address?

Cryptocurrency “coins” can be lost if the owner loses the private keys needed to spend the currency they own. It’s as if the owner had lost a bank account number and had no way to verify their identity to the bank, or if they lost the U.S. dollars they had in their wallet. The assets are gone and unusable.

The Cryptocurrency Wallet

Given the importance of these keys, and lack of recourse if they are lost, it’s obviously very important to keep track of your keys.

If you’re being careful in choosing reputable exchanges, app developers, and other services with whom to trust your cryptocurrency, you’ve made a good start in keeping your investment secure. But if you’re careless in managing the keys to your bitcoins, ether, Litecoin, or other cryptocurrency, you might as well leave your money on a cafe tabletop and walk away.

What Are the Differences Between Hot and Cold Wallets?

Just like other numbers you might wish to keep track of — credit cards, account numbers, phone numbers, passphrases — cryptocurrency keys can be stored in a variety of ways. Those who use their currencies for day-to-day purchases most likely will want them handy in a smartphone app, hardware key, or debit card that can be used for purchases. These are called “hot” wallets. Some experts advise keeping the balances in these devices and apps to a minimal amount to avoid hacking or data loss. We typically don’t walk around with thousands of dollars in U.S. currency in our old-style wallets, so this is really a continuation of the same approach to managing spending money.

Bread mobile app screenshot

A “hot” wallet, the Bread mobile app

Some investors with large balances keep their keys in “cold” wallets, or “cold storage,” i.e. a device or location that is not connected online. If funds are needed for purchases, they can be transferred to a more easily used payment medium. Cold wallets can be hardware devices, USB drives, or even paper copies of your keys.

Trezor hardware wallet

A “cold” wallet, the Trezor hardware wallet

Ledger Nano S hardware wallet

A “cold” wallet, the Ledger Nano S

Bitcoin paper wallet

A “cold” Bitcoin paper wallet

Wallets are suited to holding one or more specific cryptocurrencies, and some people have multiple wallets for different currencies and different purposes.

A paper wallet is nothing other than a printed record of your public and private keys. Some prefer their records to be completely disconnected from the internet, and a piece of paper serves that need. Just like writing down an account password on paper, however, it’s essential to keep the paper secure to avoid giving someone the ability to freely access your funds.

How to Keep your Keys, and Cryptocurrency Secure

In a post this coming Thursday, Securing Your Cryptocurrency, we’ll discuss the best strategies for backing up your cryptocurrency so that your currencies don’t become part of the millions that have been lost. We’ll cover the common (and uncommon) approaches to backing up hot wallets, cold wallets, and using paper and metal solutions to keeping your keys safe.

In the meantime, please tell us of your experiences with cryptocurrencies — good and bad — and how you’ve dealt with the issue of cryptocurrency security.

The post Cryptocurrency Security Challenges appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

What’s new in HiveMQ 3.4

Post Syndicated from The HiveMQ Team original https://www.hivemq.com/whats-new-in-hivemq-3-4

We are pleased to announce the release of HiveMQ 3.4. This version of HiveMQ is the most resilient and advanced version of HiveMQ ever. The main focus in this release was directed towards addressing the needs for the most ambitious MQTT deployments in the world for maximum performance and resilience for millions of concurrent MQTT clients. Of course, deployments of all sizes can profit from the improvements in the latest and greatest HiveMQ.

This version is a drop-in replacement for HiveMQ 3.3 and of course supports rolling upgrades with zero-downtime.

HiveMQ 3.4 brings many features that your users, administrators and plugin developers are going to love. These are the highlights:


New HiveMQ 3.4 features at a glance


HiveMQ 3.4 brings various improvements in terms of scalability, availability, resilience and observability for the cluster mechanism. Many of the new features remain under the hood, but several additions stand out:

Cluster Overload Protection

The new version has a first-of-its-kind Cluster Overload Protection. The whole cluster is able to spot MQTT clients that cause overload on nodes or the cluster as a whole and protects itself from the overload. This mechanism also protects the deployment from cascading failures due to slow or failing underlying hardware (as sometimes seen on cloud providers). This feature is enabled by default and you can learn more about the mechanism in our documentation.

Dynamic Replicates

HiveMQ’s sophisticated cluster mechanism is able to scale in a linear fashion due to extremely efficient and true data distribution mechanics based on a configured replication factor. The most important aspect of every cluster is availability, which is achieved by having eventual consistency functions in place for edge cases. The 3.4 version adds dynamic replicates to the cluster so even the most challenging edge cases involving network splits don’t lead to the sacrifice of consistency for the most important MQTT operations.

Node Stress Level Metrics

All MQTT cluster nodes are now aware of their own stress level and the stress levels of other cluster members. While all stress mitigation is handled internally by HiveMQ, experienced operators may want to monitor the individual node’s stress level (e.g with Grafana) in order to start investigating what caused the increase of load.


Operators worldwide love the HiveMQ WebUI introduced with HiveMQ 3.3. We gathered all the fantastic feedback from our users and polished the WebUI, so it’s even more useful for day-to-day broker operations and remote debugging of MQTT clients. The most important changes and additions are:

Trace Recording Download

The unique Trace Recordings functionality is without doubt a lifesaver when the behavior of individual MQTT clients needs further investigation as all interactions with the broker can be traced — at runtime and at scale! Huge production deployments may accumulate multiple gigabytes of trace recordings. HiveMQ now offers a convenient way to collect all trace recordings from all nodes, zips them and allows the download via a simple button on the WebUI. Remote debugging was never easier!

Additional Client Detail Information in WebUI

The mission of the HiveMQ WebUI is to provide easy insights to the whole production MQTT cluster for operators and administrators. Individual MQTT client investigations are a piece of cake, as all available information about clients can be viewed in detail. We further added the ability to view the restrictions a concrete client has:

  • Maximum Inflight Queue Size
  • Client Offline Queue Messages Size
  • Client Offline Message Drop Strategy

Session Invalidation

MQTT persistent sessions are one of the outstanding features of the MQTT protocol specification. Sessions which do not expire but are never reused unnecessarily consume disk space and memory. Administrators can now invalidate individual session directly in the HiveMQ WebUI for client sessions, which can be deleted safely. HiveMQ 3.4 will take care and release the resources on all cluster nodes after a session was invalidated

Web UI Polishing

Most texts on the WebUI were revisited and are now clearer and crisper. The help texts also received a major overhaul and should now be more, well, helpful. In addition, many small improvements were added, which are most of the time invisible but are here to help when you need them most. For example, the WebUI now displays a warning if cluster nodes with old versions are in the cluster (which may happen if a rolling upgrade was not finished properly)

Plugin System

One of the most popular features of HiveMQ is the extensive Plugin System, which virtually enables the integration of HiveMQ to any system and allows hooking into all aspects of the MQTT lifecycle. We listened to the feedback and are pleased to announce many improvements, big and small, for the Plugin System:

Client Session Time-to-live for individual clients

HiveMQ 3.3 offered a global configuration for setting the Time-To-Live for MQTT sessions. With the advent of HiveMQ 3.4, users can now programmatically set Time-To-Live values for individual MQTT clients and can discard a MQTT session immediately.

Individual Inflight Queues

While the Inflight Queue configuration is typically sufficient in the HiveMQ default configuration, there are some use cases that require the adjustment of this configuration. It’s now possible to change the Inflight Queue size for individual clients via the Plugin System.

Plugin Service Overload Protection

The HiveMQ Plugin System is a power-user tool and it’s possible to do unbelievably useful modifications as well as putting major stress on the system as a whole if the programmer is not careful. In order to protect the HiveMQ instances from accidental overload, a Plugin Service Overload Protection can be configured. This rate limits the Plugin Service usage and gives feedback to the application programmer in case the rate limit is exceeded. This feature is disabled by default but we strongly recommend updating your plugins to profit from this feature.

Session Attribute Store putIfNewer

This is one of the small bits you almost never need but when you do, you’re ecstatic for being able to use it. The Session Attribute Store now offers methods to put values, if the values you want to put are newer or fresher than the values already written. This is extremely useful, if multiple cluster nodes want to write to the Session Attribute Store simultaneously, as this guarantees that outdated values can no longer overwrite newer values.

Disconnection Timestamp for OnDisconnectCallback

As the OnDisconnectCallback is executed asynchronously, the client might already be gone when the callback is executed. It’s now easy to obtain the exact timestamp when a MQTT client disconnected, even if the callback is executed later on. This feature might be very interesting for many plugin developers in conjunction with the Session Attribute Store putIfNewer functionality.


We ❤️ Operators and we strive to provide all the tools needed for operating and administrating a MQTT broker cluster at scale in any environment. A key strategy for successful operations of any system is monitoring. We added some interesting new metrics you might find useful.

System Metrics

In addition to JVM Metrics, HiveMQ now also gathers Operating System Metrics for Linux Systems. So HiveMQ is able to see for itself how the operating system views the process, including native memory, the real CPU usage, and open file usage. These metrics are particularly useful, if you don’t have a monitoring agent for Linux systems setup. All metrics can be found here.

Client Disconnection Metrics

The reality of many MQTT scenarios is that not all clients are able to disconnect gracefully by sending MQTT DISCONNECT messages. HiveMQ now also exposes metrics about clients that disconnected by closing the TCP connection instead of sending a DISCONNECT packet first. This is especially useful for monitoring, if you regularly deal with clients that don’t have a stable connection to the MQTT brokers.


JMX enabled by default

JMX, the Java Monitoring Extension, is now enabled by default. Many HiveMQ operators use Application Performance Monitoring tools, which are able to hook into the metrics via JMX or use plain JMX for on-the-fly debugging. While we recommend to use official off-the-shelf plugins for monitoring, it’s now easier than ever to just use JMX if other solutions are not available to you.

Other notable improvements

The 3.4 release of HiveMQ is full of hidden gems and improvements. While it would be too much to highlight all small improvements, these notable changes stand out and contribute to the best HiveMQ release ever.

Topic Level Distribution Configuration

Our recommendation for all huge deployments with millions of devices is: Start with separate topic prefixes by bringing the dynamic topic parts directly to the beginning. The reality is that many customers have topics that are constructed like the following: “devices/{deviceId}/status”. So what happens is that all topics in this example start with a common prefix, “devices”, which is the first topic level. Unfortunately the first topic level doesn’t include a dynamic topic part. In order to guarantee the best scalability of the cluster and the best performance of the topic tree, customers can now configure how many topic levels are used for distribution. In the example outlined here, a topic level distribution of 2 would be perfect and guarantees the best scalability.

Mass disconnect performance improvements

Mass disconnections of MQTT clients can happen. This might be the case when e.g. a load balancer in front of the MQTT broker cluster drops the connections or if a mobile carrier experiences connectivity problems. Prior to HiveMQ 3.4, mass disconnect events caused stress on the cluster. Mass disconnect events are now massively optimized and even tens of millions of connection losses at the same time won’t bring the cluster into stress situations.


Replication Performance Improvements

Due to the distributed nature of a HiveMQ, data needs to be replicated across the cluster in certain events, e.g. when cluster topology changes occur. There are various internal improvements in HiveMQ version 3.4, which increase the replication performance significantly. Our engineers put special love into the replication of Queued Messages, which is now faster than ever, even for multiple millions of Queued Messages that need to be transferred across the cluster.

Updated Native SSL Libraries

The Native SSL Integration of HiveMQ was updated to the newest BoringSSL version. This results in better performance and increased security. In case you’re using SSL and you are not yet using the native SSL integration, we strongly recommend to give it a try, more than 40% performance improvement can be observed for most deployments.


Improvements for Java 9

While Java 9 was already supported for older HiveMQ versions, HiveMQ 3.4 has full-blown Java 9 support. The minimum Java version still remains Java 7, although we strongly recommend to use Java 8 or newer for the best performance of HiveMQ.

Whimsical builds and messing things up

Post Syndicated from Helen Lynn original https://www.raspberrypi.org/blog/whimsical-builds-and-messing-things-up/

Today is the early May bank holiday in England and Wales, a public holiday, and while this blog rarely rests, the Pi Towers team does. So, while we take a day with our families, our friends, and/or our favourite pastimes, I thought I’d point you at a couple of features from HackSpace magazine, our monthly magazine for makers.

To my mind, they go quite well with a deckchair in the garden, the buzz of a lawnmower a few houses down, and a view of the weeds I ought to have dealt with by now, but I’m sure you’ll find your own ambience.

Make anything with pencils – HackSpace magazine

If you want a unique piece of jewellery to show your love for pencils, follow Peter Brown’s lead. Peter glued twelve pencils together in two rows of six. He then measured the size of his finger and drilled a hole between the glued pencils using a drill bit.

First off, pencils. It hadn’t occurred to me that you could make super useful stuff like a miniature crossbow and a catapult out of pencils. Not only can you do this, you can probably go ahead and do it right now: all you need is a handful of pencils, some rubber bands, some drawing pins, and a bulldog clip (or, as you might prefer, some push pins and a binder clip). The sentence that really leaps out at me here is “To keep a handful of boys aged three to eleven occupied during a family trip, Marie decided to build mini crossbows to help their target practice.” The internet hasn’t helped me find out much about Marie, but I am in awe of her.

If you haven’t wandered off to make a stationery arsenal by now, read Lucy Rogers‘ reflections on making a right mess of things. I hope you do, because I think it’d be great if more people coped better with the fact that we all, unavoidably, fail. You probably won’t really get anywhere without a few goes where you just completely muck it all up.

A ceramic mug, broken into several pieces on the floor

Never mind. We can always line a plant pot with them.
“In Pieces” by dusk-photography / CC BY

This true of everything. Wet lab work and gardening and coding and parenting. And everything. You can share your heroic failures in the comments, if you like, as well as any historic weaponry you have fashioned from the contents of your desk tidy.

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