I remain captivated by the ideals of Literate Programming. My fork of PyLit (https://github.com/slott56/PyLit-3) coupled with Sphinx seems to handle LP programming in a very elegant way. It works like this. Write RST files describing the problem and the solution. This includes the actual implementation code. And everything else that's relevant. Run PyLit3 to build final Python code from the RST documentation. This should include the setup.py so that it can be installed properly. Run Sphinx to build pretty HTML pages (and LaTeX) from the RST documentation. I often include the unit tests along with the sphinx build so that I'm sure that things are working. The challenge is final presentation of the whole package. The HTML can be easy to publish, but it can't (trivially) be used to recover the code. We have to upload two separate and distinct things. (We could use BeautifulSoup to recover RST from HTML and then PyLit to rebuild the code. But that sounds crazy.) The RST is easy to publish, but hard to read and it requires a pass with PyLit to emit the code and then another pass with Sphinx to produce the HTML. A single upload doesn't work well. If we publish only the Python code we've defeated the point of literate programming. Even if we focus on the Python, we need to do a separate upload of HTML to providing the supporting documentation. After working with this for a while, I've found that it's simplest to have one source and several targets. I use RST ⇒ (.py, .html, .tex). This encourages me to write documentation first. I often fail, and have blocks of code with tiny summaries and non-existent explanations. PyLit allows one to use .py ⇒ .rst ⇒ .html, .tex. I've messed with this a bit and don't like it as much. Code first leaves the documentation as a kind of afterthought. How can we publish simply and cleanly: without separate uploads? Enter GitHub and gh-pages. See the "sphinxdoc-test" project for an example. Also thishttps://github.com/daler/sphinxdoc-test. The bulk of this is useful advice on a way to create the gh-pages branch from your RST source via Sphinx and some GitHub commands. Following this line of thinking, we almost have the case for three branches in a LP project. The "master" branch with the RST source. And nothing more. The "code" branch with the generated Python code created by PyLit. The "gh-pages" branch with the generated HTML created by Sphinx. I think I like this. We need three top-level directories. One has RST source. A build script would run PyLit to populate the (separate) directory for the code branch. The build script would also run Sphinx to populate a third top-level directory for the gh-pages branch. The downside of this shows up when you need to create a branch for a separate effort. You have a "some-major-change" branch to master. Where's the code? Where's the doco? You don't want to commit either of those derived work products until you merge the "some-major-change" back into master. GitHub Literate Programming There are many LP projects on GitHub. There are perhaps a dozen which focus on publishing with the Github-flavored Markdown as the source language. Because Markdown is about as easy to parse as RST, the tooling is simple. Because Markdown lacks semantic richness, I'm not switching. I've found that semantically rich markup is essential. This is a key feature of RST. It's carried forward by Sphinx to create very sophisticated markup. Think:code:`sample` vs. :py:func:`sample` vs. :py:mod:`sample` vs.:py:exc:`sample`. The final typesetting may be similar, but they are clearly semantically distinct and create separate index entries. A focus on Markdown seems to be a limitation. It's encouraging to see folks experiment with literate programming using Markdown and GitHub. Perhaps other folks will look at more sophisticated markup languages like RST. Previous Exercises See https://sourceforge.net/projects/stingrayreader/ for a seriously large literate programming effort. The HTML is also hosted at SourceForge: http://stingrayreader.sourceforge.net/index.html. This project is awkward because -- well -- I have to do a separate FTP upload of the finished pages after a change. It's done with a script, not a simple "git push." SourceForge has a GitHub repository. https://sourceforge.net/p/stingrayreader/code/ci/master/tree/. But. SourceForge doesn't use GitHub.com's UI, so it's not clear if it supports the gh-pages feature. I assume it doesn't, but, maybe it does. (I can't even login to SourceForge with Safari... I should really stop using SourceForge and switch to GitHub.) See https://github.com/slott56/HamCalc-2.1 for another complex, LP effort. This predates my dim understanding of the gh-pages branch, so it's got HTML (in doc/build/html), but it doesn't show it elegantly. I'm still not sure this three-branch Literate Programming approach is sensible. My first step should probably be to rearrange the PyLit3 project into this three-branch structure.

[This article was written by Andrew Marshall] We’ve been talking a lot about Docker over the past few weeks—with good reason. Docker’s explosive growth in popularity within the enterprise has enabled new distributed application architectures and with it a need for app-centric monitoring of your Docker containers within the context of the rest of your infrastructure. We’re thrilled to announce today that New Relic’s Docker monitoring is now generally available to New Relic customers, just in time for DockerCon 2015! (And as we noted last week, New Relic’s Docker monitoring solution has been selected by Docker for its Ecosystem Technology Partner program as a proven container monitoring solution.) Why app-centric monitoring? If you’re a software business using Docker containers, chances are you’ve done so to gain efficiencies from your system resources or portability across environments to shorten the cycle between writing and running code. Either way, adding Docker containers to your app development meant a new tier of infrastructure to monitor, which equated to a “black box” in your data—one that you had no visibility into from a monitoring perspective, Docker monitoring with New Relic is designed to “fix” this lack of monitoring visibility by adding an app-centric view of Docker containers to the existing New Relic Servers interface you already use. Now, instead of having a gap between the application and server monitoring views, we’ve added the ability to see containers with the same “first-class“ experience as you would with virtual machines and servers. You can now drill down from the application (which is really what you care about) to the individual Docker container, and then to the physical server. No more blind spots! As we strive to do with all of our products, we took the approach of “important” over “impressive” when it comes to the container information we provide to users. Based on direct feedback from customers, we’ve tried to take the mystery out of finding the right container to help you get back to developing your applications. As the way people use containers changes over time, we plan to continue to listen to our customers to help shape how we approach Docker container monitoring. Restoring 360-degree view of your application environment One example of how app-centric monitoring can impact a team moving to microservices or distributed application environments is Motus, a mobile workforce management company. Motus has been a New Relic customer for more than four years and recently has been shifting to a microservices architecture with approximately 95% of its production workload now running in Docker containers. While Docker helpd Motus gain speed and agility while reducing infrastructure complexity, the link between the application and what was happening with the container it was running on was broken. During the trial of New Relic’s Docker monitoring, Motus was able to more easily identify which container an app was running on, all the way down to the node. That was a big help when they needed to investigate an issue and determine if a new container was required.. During the beta alone, Motus estimates that using New Relic helped them to reduce the time to investigate and fix problems with its Docker containers by 30%! Motus isn’t just using New Relic to diagnose when a problem occurs. Docker monitoring with New Relic has helped Motus analyze and “right size” its containers for the application to better allocate resources for performance and budget. Get started with New Relic’s Docker monitoring today, for more information, please stop by our booth at DockerCon, June 22-23 in San Francisco! Resources: Motus Docker Monitoring Case Study Docker Monitoring with New Relic Enabling Docker Monitoring with New Relic Docker in the New Relic Community Forum

if you use https to communicate with your git repository, es, github or visualstudioonline, you usually setup credential manager to avoid entering credential for each command that contact the server. with latest versions of git you can configure wincred with this simple command. git config --global credential.helper wincred this morning i start getting error while i’m trying to push some commits to github. $ git push remote: invalid username or password. fatal: authentication failed for 'https://github.com/proximosrl/jarvis.documents tore.git/' if i remove credential helper (git config –global credential.helper unset) everything works, git ask me for user name and password and i’m able to do everything, but as soon as i re-enable credential helper, the error returned. this problem is probably originated by some corruption of stored credentials, and usually you can simply clear stored credentials and at the next operation you will be prompted for credentials and everything starts worked again. the question is, where are stored credential for wincred? if you use wincred for credential.helper, git is storing your credentials in standard windows credential manager you can simply open credential manager on your computer, figure 1: credential manager in your control panel settings opening credential manager you can manage windows and web credentials. now simply have a look to both web credentials and windows credentials, and delete everything related to github or the server you are using. the next time you issue a git command that requires authentication, you will be prompted for credentials again and the credentials will be stored again in the store. gian maria.

Don’t miss the opportunity to engage in an interactive discussion with your peers around digital transformation at MuleSoft Forum, and learn why an API-led connectivity has become IT's secret weapon. Register a seat for yourself using the following links: Gurgaon - 9th July Mumbai - 14th July Bangalore - 16th July What's in store at MuleSoft Forum: Whether you're the CIO, an Enterprise Architect, or Developer, MuleSoft Forum will provide you with a number of innovative ways to improve and transform your business. At MuleSoft Forum, you'll have the opportunity to: Learn how Mule ESB Enterprise Edition offers reliability, performance, scalability, security – all out-of-the box. See MuleSoft's connectivity platform in action in a short live demo Discover how API-Led Connectivity enables major business initiatives Attend the exclusive MuleSoft ecosystem networking reception

This week we're in Boston at DevNation, an awesome, young (second ever), and relatively intimate (~500 attendees) conference on anything and everything hard-core, cool-and-hot (DevOps, big data, Angular, IoT, you name it), and of course -- since the conference is organized by Red Hat -- totally open-source. So far I've had in-depth conversations with five super-amazing engineers, attended several inspiring keynotes, and chatted with one skilled developer after another. We'll transcribe the deeper interviews shortly, including some on topics totally unrelated to this post. But meanwhile I'd like to offer some thoughts inspired by the first day of the event. The general theme is: we're just beginning to get serious about separation of concerns. The metaphor that keeps popping into my head comes from the first keynote: machines have finally grown up. Imperatives: telling really unintelligent agents what to do (and then they sort of do whatever they please) It is trivial to observe that computers are incredibly stupid. Turing's fundamental paper is about how to figure out whether a theoretical computer will keep calculating the values of a function until the heat death of the universe (okay that's a slight oversimplification). The fact that Edsger Dijkstra felt the need to rail gently against all goto statements in any higher-level language than machine code suggests that, in 1968, far too many computers needed instructions about how to read the instructions that tell them what to do in the first place. Richard Feynman's famous lecture on computer heuristics is the condescension of the man who conceived quantum computing to the level of functional composition (hmmm) and file systems (double sigh). Stupid agents need to be told exactly what to do. Then they need to be told to pay attention to the exact part of the command that tells them exactly what they have been told to do (dude, just goto line 1343 already and shut up). Then they don't do what you told them (optimistically we call this an 'exception'), and then you send them into time out / set a break point and try to figure out where the idiot state muted off the rails. They stare blankly at the wall / variable / register and either do nothing or repeat another unintelligibly wrong result until you notice that your increment is (apparently meaninglessly to you) one bracket too deep. You sigh and tell them what to do again, and after a while they hit age thirty (life-years/debug-hours) and maybe do something useful with their (process-)lives. Well, maybe I'm straining the metaphor a little here, but you get the point because it cuts too close to home. We spend far too much time fixing stupid mistakes that we didn't even know we were making because -- like all actual human beings -- we assumed that the agent we commanded will use their common sense to iron out those few whiffs of, admit it, frank nonsense that our step-by-step instructions will probably always contain. So, at least, goes the imperative programming paradigm. The machine does what you tell it to; and the universe collapses onto itself before the last real number is computed. Functions: reliable, predictable adults Time to give credit where it's due: I'm really just riffing on the metaphor Venkat Subramanian offered in his highly enjoyable keynote on The Joy of Functional Programming yesterday morning His not-so-smart agents -- the 'programmed' of imperative programming -- were toddlers. Since I don't have any kids, I can't presume to understand this experience fully (although I did grow up with three younger brothers..). But the general idea is: imperative programming is tricky because, when you spell everything out super literally, it's very hard to tell exactly why what you thought should happen didn't. Venkat's talk was a whirlwind of functional concepts, from the thrill of immutability to the self-evident utility of memoization. For random (Myers-Briggs?) reasons, the object-oriented paradigm never seemed very intuitive to me -- I've gravitated towards functional style even when the problem domain wasn't actually modeled very well by functions -- but Venkat's side-by-side implementations of simple calculations in OO and functional Java showed the readability delta very clearly. Functional code is beautiful because it looks like its purpose. It tells you flat-out: here is what I do; and then it does it. But immutable functions are also beautiful because they do exactly the same thing every time. I couldn't count on my two year old brother very much at all because given a certain input I had pretty much no idea what would come out. But we all count on our grown-up collaborators to output exactly what they should, given a definite input, predictably and reliably every time. Of course, people also do more than expected -- every intervention of intelligence is an injection of creativity, not generated by the definition of the function -- but at least they do what you need them to do and no less. Containers: grown-ups with good boundaries I'm picking out just one aspect of the resurgent 'joy' of functional programming because the renaissance of containerization (another 'old' technology that is just now really taking off) is, I think, a part of the same shift toward, let's say, treating computers as adults. If functions are reliable agents, then applications in well-defined containers are self-sufficient agents who know exactly what they need from others and neither require nor demand anything more. If apps on dedicated VMs are teenagers negotiating personal boundaries by waking/booting up independently (and taking far too long -- and far too many resources -- to do so, given their meager output) -- or bubble boys, isolated in ways that are unfortunate in order to isolate in ways that are absolutely necessary -- then containerized applications are subway-riders who jam into the train without offending anyone or campers who can live anywhere with just a backpack of just the stuff they need. Of course, subway-riders and campers do more than just not-mess-up. But what's kind of neat about containers is that -- like an adult with good boundaries -- clearly defined bounds and interfaces free up the application / mind to do whatever world-changing thing the developer / human has cooked up. I'll come back to this metaphor in a later article. (Mesh networks, SDN, and ad-hoc computing are all part of the same picture, I think. Kubernetes probably is too, along with event-driven and reactive programming, the actor model, dreams of Smalltalk, and of course REST, at least of the HATEOAS flavor.) But maybe this isn't a good way to think about some of these recent sparks in devworld within a single paradigm -- and maybe my perpetual discomfort with OO is influencing me too much. What do you think?

Last week I was showing the foul graph to my colleague Alistair who came up with the idea of running a ‘foul revenge’ query to find out which players gained revenge for a foul with one of their own later in them match. Queries like this are very path centric and therefore work well in a graph. To recap, this is what the foul graph looks like: The first thing that we need to do is connect the fouls in a linked list based on time so that we can query their order more easily. We can do this with the following query: MATCH (foul:Foul)-[:COMMITTED_IN_MATCH]->(match) WITH foul,match ORDER BY match.id, foul.sortableTime WITH match, COLLECT(foul) AS fouls FOREACH(i in range(0, length(fouls) -2) | FOREACH(foul1 in [fouls[i]] | FOREACH (foul2 in [fouls[i+1]] | MERGE (foul1)-[:NEXT]->(foul2) ))); This query collects fouls grouped by match and then adds a ‘NEXT’ relationship between adjacent fouls. The graph now looks like this: Now let’s find the revenge foulers in the Bayern Munich vs Barcelona match. We’re looking for the following pattern: This translates to the following cypher query: match (foul1:Foul)-[:COMMITTED_AGAINST]->(app1)-[:COMMITTED_FOUL]->(foul2)-[:COMMITTED_AGAINST]->(app2)-[:COMMITTED_FOUL]->(foul1), (player1)-[:MADE_APPEARANCE]->(app1), (player2)-[:MADE_APPEARANCE]->(app2), (foul1)-[:COMMITTED_IN_MATCH]->(match:Match {id: "32683310"})<-[:COMMITTED_IN_MATCH]-(foul2) WHERE (foul1)-[:NEXT*]->(foul2) RETURN player2.name AS firstFouler, player1.name AS revengeFouler, foul1.time, foul1.location, foul2.time, foul2.location I’ve added in a few extra parts to the pattern to pull out the players involved and to find the revenge foulers in a specific match – the Bayern Munich vs Barcelona Semi Final 2nd leg. We end up with the following revenge fouls: We can see here that Dani Alves actually gains revenge on Bastian Schweinsteiger twice for a foul he made in the 10th minute. If we tweak the query to the following we can get a visual representation of the revenge fouls as well: match (foul1:Foul)-[:COMMITTED_AGAINST]->(app1)-[:COMMITTED_FOUL]->(foul2)-[:COMMITTED_AGAINST]->(app2)-[:COMMITTED_FOUL]->(foul1), (player1)-[:MADE_APPEARANCE]->(app1), (player2)-[:MADE_APPEARANCE]->(app2), (foul1)-[:COMMITTED_IN_MATCH]->(match:Match {id: "32683310"})<-[:COMMITTED_IN_MATCH]-(foul2), (foul1)-[:NEXT*]->(foul2) RETURN * At the moment I’ve restricted the revenge concept to single matches but I wonder whether it’d be more interesting to create a linked list of fouls which crosses matches between teams in the same season. The code for all of this is on github – the README is a bit sketchy at the moment but I’ll be fixing that up soon.

From the DevNation Agenda site: You've probably heard a lot about Linux containers and the exciting potential they hold. In this presentation, Matt Hicks will cover how Docker and Kubernetes have evolved to fundamentally change how you will approach development and operations. If you are looking for an understanding of the technology and how it relates to the common roles in IT today, this is the talk to watch. Speaker: Matt Hicks -- Vice President of engineering, Red Hat Matt Hicks is a founding member of the OpenShift by Red Hat team. He has spent more than a decade in software engineering, with a variety of roles in development, operations, architecture, and management. His real expertise is in bridging the gap between developing code and actually running it in production. An expert in IT and cloud-based architectures, he spends his time these days evolving OpenShift to use the power of cloud and make developers more productive.

You will aggregate a lot of logs over the lifetime of your product and codebase, so it’s important to be able to search through them. In the rare case of a security issue, not having that capability is incredibly painful. You might be able to use services that allow you to search through the logs of the last two weeks quickly. But what if you want to search through the last six months, a year, or even further? That availability can be rather expensive or not even an option at all with existing services. Many hosted log services provide S3 archival support which we can use to build a long-term log analysis infrastructure with AWS Redshift. Recently I’ve set up scripts to be able to create that infrastructure whenever we need it at Codeship. AWS Redshift AWS Redshift is a data warehousing solution by AWS. It has an easy clustering and ingestion mechanism ideal for loading large log files and then searching through them with SQL. As it automatically balances your log files across several machines, you can easily scale up if you need more speed. As I said earlier, looking through large amounts of log files is a relatively rare occasion; you don’t need this infrastructure to be around all the time, which makes it a perfect use case for AWS. Setting Up Your Log Analysis Let’s walk through the scripts that drive our long-term log analysis infrastructure. You can check them out in the flomotlik/redshift-logging GitHub repository. I’ll take you step by step through configuring the whole setup of the environment variables needed, as well as starting the creation of the cluster and searching the logs. But first, let’s get a high-level overview of what the setup script is doing before going into all the different options that you can set: Creates an AWS Redshift cluster. You can configure the number of servers and which server type should be used. Waits for the cluster to become ready. Creates a SQL table inside the Redshift cluster to load the log files into. Ingests all log files into the Redshift cluster from AWS S3. Cleans up the database and prints the psql access command to connect into the cluster. Be sure to check out the script on GitHub before we go into all the different options that you can set through the .env file. Options to set The following is a list of all the options available to you. You can simply copy the .env.template file to .env and then fill in all the options to get picked up. AWS_ACCESS_KEY_ID AWS key of the account that should run the Redshift cluster. AWS_SECRET_ACCESS_KEY AWS secret key of the account that should run the Redshift cluster. AWS_REGION=us-east-1 AWS region the cluster should run in, default us-east-1. Make sure to use the same region that is used for archiving your logs to S3 to have them close. REDSHIFT_USERNAME Username to connect with psql into the cluster. REDSHIFT_PASSWORD Password to connect with psql into the cluster. S3_AWS_ACCESS_KEY_ID AWS key that has access to the S3 bucket you want to pull your logs from. We run the log analysis cluster in our AWS Sandbox account but pull the logs from our production AWS account so the Redshift cluster doesn’t impact production in any way. S3_AWS_SECRET_ACCESS_KEY AWS secret key that has access to the S3 bucket you want to pull your logs from. PORT=5439 Port to connect to with psql. CLUSTER_TYPE=single-node The cluster type can be single-node or multi-node. Multi-node clusters get auto-balanced which gives you more speed at a higher cost. NODE_TYPE Instance type that’s used for the nodes of the cluster. Check out the Redshift Documentation for details on the instance types and their differences. NUMBER_OF_NODES=10 Number of nodes when running in multi-mode. CLUSTER_IDENTIFIER=log-analysis DB_NAME=log-analysis S3_PATH=s3://your_s3_bucket/papertrail/logs/862693/dt=2015 Database format and failed loads When ingesting log statements into the cluster, make sure to check the amount of failed loads that are happening. You might have to edit the database format to fit to your specific log output style. You can debug this easily by creating a single-node cluster first that only loads a small subset of your logs and is very fast as a result. Make sure to have none or nearly no failed loads before you extend to the whole cluster. In case there are issues, check out the documentation of the copy command which loads your logs into the database and the parameters in the setup script for that. Example and benchmarks It’s a quick thing to set up the whole cluster and run example queries against it. For example, I’ll load all of our logs of the last nine months into a Redshift cluster and run several queries against it. I haven’t spent any time on optimizing the table, but you could definitely gain some more speed out of the whole system if necessary. It’s just fast enough already for us out of the box. As you can see here, loading all logs of May — more than 600 million log lines — took only 12 minutes on a cluster of 10 machines. We could easily load more than one month into that 10-machine cluster since there’s more than enough storage available, but for this post, one month is enough. After that, we’re able to search through the history of all of our applications and past servers through SQL. We connect with our psql client and send of SQL queries against the “events’ database. For example, what if we want to know how many build servers reported logs in May: loganalysis=# select count(distinct(source_name)) from events where source_name LIKE 'i-%'; count ------- 801 (1 row) So in May, we had 801 EC2 build servers running for our customers. That query took ~3 seconds to finish. Or let’s say we want to know how many people accessed the configuration page of our main repository (the project ID is hidden with XXXX): loganalysis=# select count(*) from events where source_name = 'mothership' and program LIKE 'app/web%' and message LIKE 'method=GET path=/projects/XXXX/configure_tests%'; count ------- 15 (1 row) So now we know that there were 15 accesses on that configuration page throughout May. We can also get all the details, including who accessed it when through our logs. This could help in case of any security issues we’d need to look into. The query took about 40 seconds to go though all of our logs, but it could be optimized on Redshift even more. Those are just some of the queries you could use to look through your logs, gaining more insight into your customers’ use of your system. And you et all of that with a setup that costs $2.50 an hour, can be shut down immediately, and recreated any time you need access to that data again. Conclusions Being able to search through and learn from your history is incredibly important for building a large infrastructure. You need to be able to look into your history easily, especially when it comes to security issues. With AWS Redshift, you have a great tool in hand that allows you to start an ad hoc analytics infrastructure that’s fast and cheap for short-term reviews. Of course, Redshift can do a lot more as well. Let us know what your processes and tools around logging, storage, and search are in the comments.

While working on different web projects I have accumulated a large pool of tools and services to facilitate the work of developers, system administrators and DevOps One of the first challenges, that every developer faces at the end of each project is backup configuration and maintenance of media files, UGC, databases, application and servers' data (e.g. configuration files). Nowadays, there are a lot of solutions to make a snapshot backup of the entire server, and I decided to make a list of most convinient and really useful tools and services. rsync - http://linux.die.net/man/1/rsync Rsync is a fast and extraordinarily versatile file copying tool. It can copy locally, to/from another host over any remote shell, or to/from a remote rsync daemon. It offers a large number of options that control every aspect of its behavior and permit very flexible specification of the set of files to be copied. It's a build in Linux tool. Real hardcore =) rsnapshot - http://rsnapshot.org/ rsnapshot is a filesystem snapshot utility for making backups of local and remote systems. Using rsync and hard links, it is possible to keep multiple, full backups instantly available. The disk space required is just a little more than the space of one full backup, plus incrementals. Depending on your configuration, it is quite possible to set up in just a few minutes. Files can be restored by the users who own them, without the root user getting involved. Stackoverflow users recommended it to me couple of years ago and I thinks that is a really good solutions, which unites the best from rsync and Linux filesystem. Snapper - http://snapper.io/ Snapper is a tool for Linux filesystem snapshot management. Apart from the obvious creation and deletion of snapshots, it can compare snapshots and revert differences between snapshots. In simple terms, this allows root and non-root users to view older versions of files and revert changes. Allows you to configure schedule for the backups, automatically deletes old snapshots. The only sad thing is that Snapper has no updates since 2014. backup2l - http://backup2l.sourceforge.net/ backup2l is a lightweight command line tool for generating, maintaining and restoring backups on a mountable file system (e. g. hard disk). The main design goals are are low maintenance effort, efficiency, transparency and robustness. In a default installation, backups are created autonomously by a cron script. The script, that I've found on sourceforge and even used on couple of my projects 5 years ago. But it is not being updated since 2009. FlyBack - https://www.linuxlinks.com/flyback/ FlyBack is software for system backup and restore, which offers similar functionality to the Mac OS X Leopard's Time Machine. Linux has almost all of the required technology already built in to recreate it. FlyBack is a snapshot-based backup tool based on rsync. It creates successive backup directories mirroring the files users want to backup, but hard-links unchanged files to the previous backup. Plenty of settings, mostly build for desktop computers, simple UI. TimeVault - https://wiki.ubuntu.com/TimeVault TimeVault monitors files for changes and takes snapshots after some user-specified delay. It is a simple front-end for making snapshots of a set of directories. Snapshots are a copy of a directory structure or file at a certain point in time. They use very little space for files which have not changed since the last snapshot was made, as they use hard links that point to existing backups. TimeVault makes all the work silently in background and is fully automated solution. Currently it gets no updates but it was a good solution when it just released. Box Backup - http://www.boxbackup.org/ Box Backup is an open source, completely automatic, on-line backup system. A backup daemon runs on systems to be backed up, and copies encrypted data to the server when it notices changes - so backups are continuous and up-to-date (although traditional snapshot backups are possible too). All backed up data is stored on the server in files on a filesystem - no tape, archive or other special devices are required. BitCalm - https://bitcalm.com BitCalm makes it easy for web developers to set up backup of applications on Linux servers just in one minute. It is SaaS for server backups. After installing python client user can manage backups for files and even databases in web-interface. Service provides Amazon S3 as a storage and allows users to connect their own storage for backups. All backups are incremental. Service is built for servers and supports all popular Linux based OS: Ubuntu, Debian, CentOS, ArchLinux. To let user be calm, service sends daily reports and notifications. BitCalm allows to manage multiple backups in a single account and user can restore the backup to any server added to service.

Mounting an EBS volume to a Docker instance running on Amazon Elastic Beanstalk (EB) is surprisingly tricky. The good news is that it is possible. I will describe how to automatically create and mount a new EBS volume (optionally based on a snapshot). If you would prefer to mount a specific, existing EBS volume, you should check out leg100’s docker-ebs-attach (using AWS API to mount the volume) that you can use either in a multi-container setup or just include the relevant parts in your own Dockerfile. The problem with EBS volumes is that, if I am correct, a volume can only be mounted to a single EC2 instance – and thus doesn’t play well with EB’s autoscaling. That is why EB supports only creating and mounting a fresh volume for each instance. Why would you want to use an auto-created EBS volume? You can already use a docker VOLUME to mount a directory on the host system’s ephemeral storage to make data persistent across docker restarts/redeploys. The only advantage of EBS is that it survives restarts of the EC2 instance but that is something that, I suppose, happens rarely. I suspect that in most cases EB actually creates a new EC2 instance and then destroys the old one. One possible benefit of an EBS volume is that you can take a snapshot of it and use that to launch future instances. I’m now inclined to believe that a better solution in most cases is to set up automatic backup to and restore from S3, f.ex. using duplicity with its S3 backend (as I do for my NAS). Anyway, here is how I got EBS volume mounting working. There are 4 parts to the solution: Configure EB to create an EBS mount for your instances Add custom EB commands to format and mount the volume upon first use Restart the Docker daemon after the volume is mounted so that it will see it (see this discussion) Configure Docker to mount the (mounted) volume inside the container 1-3.: .ebextensions/01-ebs.config: # .ebextensions/01-ebs.config commands: 01format-volume: command: mkfs -t ext3 /dev/sdh test: file -sL /dev/sdh | grep -v 'ext3 filesystem' # ^ prints '/dev/sdh: data' if not formatted 02attach-volume: ### Note: The volume may be renamed by the Kernel, e.g. sdh -> xvdh but # /dev/ will then contain a symlink from the old to the new name command: | mkdir /media/ebs_volume mount /dev/sdh /media/ebs_volume service docker restart # We must restart Docker daemon or it wont' see the new mount test: sh -c "! grep -qs '/media/ebs_volume' /proc/mounts" option_settings: # Tell EB to create a 100GB volume and mount it to /dev/sdh - namespace: aws:autoscaling:launchconfiguration option_name: BlockDeviceMappings value: /dev/sdh=:100 4.: Dockerrun.aws.json and Dockerfile: Dockerrun.aws.json: mount the host’s /media/ebs_volume as /var/easydeploy/share inside the container: { "AWSEBDockerrunVersion": "1", "Volumes": [ { "HostDirectory": "/media/ebs_volume", "ContainerDirectory": "/var/easydeploy/share" } ] } Dockerfile: Tell Docker to use a directory on the host system as /var/easydeploy/share – either a randomly generated one or the one given via the -m mount option to docker run: ... VOLUME ["/var/easydeploy/share"] ...

hadoop is best known for map reduce and it's distributed file system (hdfs). recently other productivity tools developed on top of these will form a complete ecosystem of hadoop. most of the projects are hosted under apache software foundation . hadoop ecosystem projects are listed below. hadoop common a set of components and interfaces for distributed file system and i/o (serialization, java rpc, persistent data structures) http://hadoop.apache.org/ hadoop ecosystem hdfs a distributed file system that runs on large clusters of commodity hardware. hadoop distributed file system, hdfs renamed form ndfs. scalable data store that stores semi-structured, un-structured and structured data. http://hadoop.apache.org/docs/r2.3.0/hadoop-project-dist/hadoop-hdfs/hdfsuserguide.html http://wiki.apache.org/hadoop/hdfs map reduce map reduce is the distributed, parallel computing programming model for hadoop. inspired from google map reduce research paper . hadoop includes implementation of map reduce programming model. in map reduce there are two phases, not surprisingly map and reduce. to be precise in between map and reduce phase, there is another phase called sort and shuffle. job tracker in name node machine manages other cluster nodes. map reduce programming can be written in java. if you like sql or other non- java languages, you are still in luck. you can use utility called hadoop streaming. http://wiki.apache.org/hadoop/hadoopmapreduce hadoop streaming a utility to enable map reduce code in many languages like c, perl, python, c++, bash etc., examples include a python mapper and awk reducer. http://hadoop.apache.org/docs/r1.2.1/streaming.html avro a serialization system for efficient, cross-language rpc and persistent data storage. avro is a framework for performing remote procedure calls and data serialization. in the context of hadoop, it can be used to pass data from one program or language to another, e.g. from c to pig. it is particularly suited for use with scripting languages such as pig, because data is always stored with its schema in avro. http://avro.apache.org/ apache thrift apache thrift allows you to define data types and service interfaces in a simple definition file. taking that file as input, the compiler generates code to be used to easily build rpc clients and servers that communicate seamlessly across programming languages. instead of writing a load of boilerplate code to serialize and transport your objects and invoke remote methods, you can get right down to business. http://thrift.apache.org/ hive and hue if you like sql, you would be delighted to hear that you can write sql and hive convert it to a map reduce job. but, you don't get a full ansi-sql environment. hue gives you a browser based graphical interface to do your hive work. hue features a file browser for hdfs, a job browser for map reduce/yarn, an hbase browser, query editors for hive, pig, cloudera impala and sqoop2.it also ships with an oozie application for creating and monitoring workflows, a zookeeper browser and an sdk. pig a high-level programming data flow language and execution environment to do map reduce coding the pig language is called pig latin. you may find naming conventions some what un-conventional, but you get incredible price-performance and high availability. https://pig.apache.org/ jaql jaql is a functional, declarative programming language designed especially for working with large volumes of structured, semi-structured and unstructured data. as its name implies, a primary use of jaql is to handle data stored as json documents, but jaql can work on various types of data. for example, it can support xml, comma-separated values (csv) data and flat files. a "sql within jaql" capability lets programmers work with structured sql data while employing a json data model that's less restrictive than its structured query language counterparts. 1. jaql in google code 2. what is jaql? by ibm sqoop sqoop provides a bi-directional data transfer between hadoop -hdfs and your favorite relational database. for example you might be storing your app data in relational store such as oracle, now you want to scale your application with hadoop so you can migrate oracle database data to hadoop hdfs using sqoop. http://sqoop.apache.org/ oozie manages hadoop workflow. this doesn't replace your scheduler or BPM tooling, but it will provide if-then-else branching and control with hadoop jobs. https://oozie.apache.org/ zookeeper a distributed, highly available coordination service. zookeeper provides primitives such as distributed locks that can be used for building the highly scalable applications. it is used to manage synchronization for cluster. http://zookeeper.apache.org/ hbase based on google's bigtable , hbase "is an open-source, distributed, version, column-oriented store" that sits on top of hdfs. a super scalable key-value store. it works very much like a persistent hash-map (for python developers think like a dictionary). it is not a conventional relational database. it is a distributed, column oriented database. hbase uses hdfs for it's underlying. supports both batch-style computations using map reduce and point queries for random reads. https://hbase.apache.org/ cassandra a column oriented nosql data store which offers scalability, high availability with out compromising on performance. it perfect platform for commodity hardware and cloud infrastructure.cassandra's data model offers the convenience of column indexes with the performance of log-structured updates, strong support for de-normalization and materialized views , and powerful built-in caching. http://cassandra.apache.org/ flume a real time loader for streaming your data into hadoop. it stores data in hdfs and hbase.flume "channels" data between "sources" and "sinks" and its data harvesting can either be scheduled or event-driven. possible sources for flume include avro, files, and system logs, and possible sinks include hdfs and hbase. http://flume.apache.org/ mahout machine learning for hadoop, used for predictive analytics and other advanced analysis. there are currently four main groups of algorithms in mahout: recommendations, a.k.a. collective filtering classification, a.k.a categorization clustering frequent item set mining, a.k.a parallel frequent pattern mining mahout is not simply a collection of pre-existing algorithms; many machine learning algorithms are intrinsically non-scalable; that is, given the types of operations they perform, they cannot be executed as a set of parallel processes. algorithms in the mahout library belong to the subset that can be executed in a distributed fashion. http://en.wikipedia.org/wiki/list_of_machine_learning_algorithms https://www.coursera.org/course/machlearning https://mahout.apache.org/ fuse makes the hdfs system to look like a regular file system so that you can use ls, rm, cd etc., directly on hdfs data. whirr apache whirr is a set of libraries for running cloud services. whirr provides a cloud-neutral way to run services. you don't have to worry about the idiosyncrasies of each provider.a common service api. the details of provisioning are particular to the service. smart defaults for services. you can get a properly configured system running quickly, while still being able to override settings as needed. you can also use whirr as a command line tool for deploying clusters. https://whirr.apache.org/ giraph an open source graph processing api like pregel from google https://giraph.apache.org/ chukwa chukwa, an incubator project on apache, is a data collection and analysis system built on top of hdfs and map reduce. tailored for collecting logs and other data from distributed monitoring systems, chukwa provides a workflow that allows for incremental data collection, processing and storage in hadoop. it is included in the apache hadoop distribution as an independent module. https://chukwa.apache.org/ drill apache drill, an incubator project on apache, is an open-source software framework that supports data-intensive distributed applications for interactive analysis of large-scale datasets. drill is the open source version of google's dremel system which is available as an iaas service called google big query. one explicitly stated design goal is that drill is able to scale to 10,000 servers or more and to be able to process petabytes of data and trillions of records in seconds. http://incubator.apache.org/drill/ impala (cloudera) released by cloudera, impala is an open-source project which, like apache drill, was inspired by google's paper on dremel; the purpose of both is to facilitate real-time querying of data in hdfs or hbase. impala uses an sql-like language that, though similar to hiveql, is currently more limited than hiveql. because impala relies on the hive meta store, hive must be installed on a cluster in order for impala to work. the secret behind impala's speed is that it "circumvents map reduce to directly access the data through a specialized distributed query engine that is very similar to those found in commercial parallel rdbmss." (source: cloudera) http://www.cloudera.com/content/cloudera/en/products-and-services/cdh/impala.html http://training.cloudera.com/elearning/impala/

I have a large Java project with many sub modules, and they have simple top down dependencies like this: ProjectX +-ModuleLibA +-ModuleLibB +-ModuleCdiLibC +-ModuleCdiLibC2 +-ModuleLibD +-ModuleCdiLibE +-ModuleCdiLibE2 +-ModuleCdiLibE3 +-ModuleLibF +-ModuleLibG +-ModuleWebAppX Each of these modules has their own third party dependency jars. When I say top down, it simply means Module from bottom have all the one above sub module and its third party dependencies as well. The project is large, and with many files, but the structure is straight forward. It does have large amount of third party jars though. At the end, the webapp would have over 100 jars packaged in WEB-INF/lib folder! When you create this project structure in IntelliJ IDE (no I do not have the luxury of using Maven in this case), all the third party dependencies are nicely exported and managed from one Module to another as I create my Project with existing source and third parties jars. I do not need to re-define any redudant jars libraries definitions between Modules. When it come to define ModuleWebAppX at the end, all I have to do is to add ModuleLibG as a project dependency, and it brings all the other "transitives" dependent jars in! This is all done by IntelliJ IDE, which is very nice! IntelliJ IDE also let you setup Artifacts from your project to prepare for package and deployment that can run inside your IDE servers. By default, any web application will have an option to create a war:exploded artifact definition, and the IDE will automatically copy and update your project build artifacts into this output folder, and it can be deploy/redeploy into any EE server as exploded mode nicely. All these work really smoothly, until there is one problem that hit hard! The way IntelliJ IDE package default war:exploded artifact is that it will copy all the .class files generated from each Modules into a single "out/artifact/ProjectX_war_exploded" output folder. This works most of the time when our Java package and classes are unique, but not so with resource files that's not unique! My project uses several dependent CDI based modules. As you might know, each CDI module suppose to define their own, one and single location at META-INF/beans.xml to enable it and to customize CDI behavior. But becuase IntelliJ IDE flatten everything into a single output directory, I've lost the unique beans.xml file per each Module! This problem is hard to troubleshoot since it doesn't produce any error at first, nor it stops the web app from running. It just not able to load certain CDI beans that you have customized in the beans.xml!!! To resolve this, I have to make the IntelliJIDE artifact dependent modules to generate it's JAR instead of all copy into a single output. But we still want it to auto copy generated build files into the JAR archive automatically when we make a change. Lukcly IntelliJ has this feature. This is how I do it: 1. Open your project settings then select Artifacts on left. 2. Choose your war:exploded artifacts and look to your right. 3. Under OutputLayout tab, expand WEB-INF/lib, then right clik and "Create Archive" > Enter your moduleX name.jar. 4. Right click this newly created archive moduleX.jar name, then "Add Copy of" > "Module Output" and select one of your dependent module. 5. Repeat for each of the CDI based Modules! I wish there is a easier way to do across all Modules for this, but at least this manual solution works!

Log collection is essential to properly analyzing issues in production. An interface to search and be notified about exceptions on all your servers is a must. Well, if you have one server, you can easily ssh to it and check the logs, of course, but for larger deployments, collecting logs centrally is way more preferable than logging to 10 machines in order to find “what happened”. There are many options to do that, roughly separated in two groups – 3rd party services and software to be installed by you. 3rd party (or “cloud-based” if you want) log collection services include Splunk,Loggly, Papertrail, Sumologic. They are very easy to setup and you pay for what you use. Basically, you send each message (e.g. via a custom logback appender) to a provider’s endpoint, and then use the dashboard to analyze the data. In many cases that would be the preferred way to go. In other cases, however, company policy may frown upon using 3rd party services to store company-specific data, or additional costs may be undesired. In these cases extra effort needs to be put into installing and managing an internal log collection software. They work in a similar way, but implementation details may differ (e.g. instead of sending messages with an appender to a target endpoint, the software, using some sort of an agent, collects local logs and aggregates them). Open-source options include Graylog, FluentD, Flume, Logstash. After a very quick research, I considered graylog to fit our needs best, so below is a description of the installation procedure on AWS (though the first part applies regardless of the infrastructure). The first thing to look at are the ready-to-use images provided by graylog, including docker, openstack, vagrant and AWS. Unfortunately, the AWS version has two drawbacks – it’s using Ubuntu, rather than the Amazon AMI. That’s not a huge issue, although some generic scripts you use in your stack may have to be rewritten. The other was the dealbreaker – when you start it, it doesn’t run a web interface, although it claims it should. Only mongodb, elasticsearch and graylog-server are started. Having 2 instances – one web, and one for the rest would complicate things, so I opted for manual installation. Graylog has two components – the server, which handles the input, indexing and searching, and the web interface, which is a nice UI that communicates with the server. The web interface uses mongodb for metadata, and the server uses elasticsearch to store the incoming logs. Below is a bash script (CentOS) that handles the installation. Note that there is no “sudo”, because initialization scripts are executed as root on AWS. #!/bin/bash # install pwgen for password-generation yum upgrade ca-certificates --enablerepo=epel yum --enablerepo=epel -y install pwgen # mongodb cat >/etc/yum.repos.d/mongodb-org.repo <<'EOT' [mongodb-org] name=MongoDB Repository baseurl=http://downloads-distro.mongodb.org/repo/redhat/os/x86_64/ gpgcheck=0 enabled=1 EOT yum -y install mongodb-org chkconfig mongod on service mongod start # elasticsearch rpm --import https://packages.elasticsearch.org/GPG-KEY-elasticsearch cat >/etc/yum.repos.d/elasticsearch.repo <<'EOT' [elasticsearch-1.4] name=Elasticsearch repository for 1.4.x packages baseurl=http://packages.elasticsearch.org/elasticsearch/1.4/centos gpgcheck=1 gpgkey=http://packages.elasticsearch.org/GPG-KEY-elasticsearch enabled=1 EOT yum -y install elasticsearch chkconfig --add elasticsearch # configure elasticsearch sed -i -- 's/#cluster.name: elasticsearch/cluster.name: graylog2/g' /etc/elasticsearch/elasticsearch.yml sed -i -- 's/#network.bind_host: localhost/network.bind_host: localhost/g' /etc/elasticsearch/elasticsearch.yml service elasticsearch stop service elasticsearch start # java yum -y update yum -y install java-1.7.0-openjdk update-alternatives --set java /usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java # graylog wget https://packages.graylog2.org/releases/graylog2-server/graylog-1.0.1.tgz tar xvzf graylog-1.0.1.tgz -C /opt/ mv /opt/graylog-1.0.1/ /opt/graylog/ cp /opt/graylog/bin/graylogctl /etc/init.d/graylog sed -i -e 's/GRAYLOG2_SERVER_JAR=\${GRAYLOG2_SERVER_JAR:=graylog.jar}/GRAYLOG2_SERVER_JAR=\${GRAYLOG2_SERVER_JAR:=\/opt\/graylog\/graylog.jar}/' /etc/init.d/graylog sed -i -e 's/LOG_FILE=\${LOG_FILE:=log\/graylog-server.log}/LOG_FILE=\${LOG_FILE:=\/var\/log\/graylog-server.log}/' /etc/init.d/graylog cat >/etc/init.d/graylog <<'EOT' #!/bin/bash # chkconfig: 345 90 60 # description: graylog control sh /opt/graylog/bin/graylogctl $1 EOT chkconfig --add graylog chkconfig graylog on chmod +x /etc/init.d/graylog # graylog web wget https://packages.graylog2.org/releases/graylog2-web-interface/graylog-web-interface-1.0.1.tgz tar xvzf graylog-web-interface-1.0.1.tgz -C /opt/ mv /opt/graylog-web-interface-1.0.1/ /opt/graylog-web/ cat >/etc/init.d/graylog-web <<'EOT' #!/bin/bash # chkconfig: 345 91 61 # description: graylog web interface sh /opt/graylog-web/bin/graylog-web-interface > /dev/null 2>&1 & EOT chkconfig --add graylog-web chkconfig graylog-web on chmod +x /etc/init.d/graylog-web #configure mkdir --parents /etc/graylog/server/ cp /opt/graylog/graylog.conf.example /etc/graylog/server/server.conf sed -i -e 's/password_secret =.*/password_secret = '$(pwgen -s 96 1)'/' /etc/graylog/server/server.conf sed -i -e 's/root_password_sha2 =.*/root_password_sha2 = '$(echo -n password | shasum -a 256 | awk '{print $1}')'/' /etc/graylog/server/server.conf sed -i -e 's/application.secret=""/application.secret="'$(pwgen -s 96 1)'"/g' /opt/graylog-web/conf/graylog-web-interface.conf sed -i -e 's/graylog2-server.uris=""/graylog2-server.uris="http:\/\/127.0.0.1:12900\/"/g' /opt/graylog-web/conf/graylog-web-interface.conf service graylog start sleep 30 service graylog-web start You may also want to set a TTL (auto-expiration) for messages, so that you don’t store old logs forever. Here’s how # wait for the index to be created INDEXES=$(curl --silent "http://localhost:9200/_cat/indices") until [[ "$INDEXES" =~ "graylog2_0" ]]; do sleep 5 echo "Index not yet created. Indexes: $INDEXES" INDEXES=$(curl --silent "http://localhost:9200/_cat/indices") done # set each indexed message auto-expiration (ttl) curl -XPUT "http://localhost:9200/graylog2_0/message/_mapping" -d'{"message": {"_ttl" : { "enabled" : true, "default" : "15d" }}' Now you have everything running on the instance. Then you have to do some AWS-specific things (if using CloudFormation, that would include a pile of JSON). Here’s the list: you can either have an auto-scaling group with one instance, or a single instance. I prefer the ASG, though the other one is a bit simpler. The ASG gives you auto-respawn if the instance dies. set the above script to be invoked in the UserData of the launch configuration of the instance/asg (e.g. by getting it from s3 first) allow UDP port 12201 (the default logging port). That should happen for the instance/asg security group (inbound), for the application nodes security group (outbound), and also as a network ACL of your VPC. Test the UDP connection to make sure it really goes through. Keep the access restricted for all sources, except for your instances. you need to pass the private IP address of your graylog server instance to all the application nodes. That’s tricky on AWS, as private IP addresses change. That’s why you need something stable. You can’t use an ELB (load balancer), because it doesn’t support UDP. There are two options: Associate an Elastic IP with the node on startup. Pass that IP to the application nodes. But there’s a catch – if they connect to the elastic IP, that would go via NAT (if you have such), and you may have to open your instance “to the world”. So, you must turn the elastic IP into its corresponding public DNS. The DNS then will be resolved to the private IP. You can do that by manually and hacky: 1 GRAYLOG_ADDRESS="ec2-$GRAYLOG_ADDRESS//./-}.us-west-1.compute.amazonaws.com" or you can use the AWS EC2 CLI to obtain the instance details of the instance that the elastic IP is associated with, and then with another call obtain its Public DNS. Instead of using an Elastic IP, which limits you to a single instance, you can use Route53 (the AWS DNS manager). That way, when a graylog server instance starts, it can append itself to a route53 record, that way allowing for a round-robin DNS of multiple graylog instances that are in a cluster. Manipulating the Route53 records is again done via the AWS CLI. Then you just pass the domain name to applications nodes, so that they can send messages. alternatively, you can install graylog-server on all the nodes (as an agent), and point them to an elasticsearch cluster. But that’s more complicated and probably not the intended way to do it configure your logging framework to send messages to graylog. There are standard GELF (the greylog format) appenders, e.g. this one, and the only thing you have to do is use the Public DNS environment variable in the logback.xml (which supports environment variable resolution). You should make the web interface accessible outside the network, so you can use an ELB for that, or the round-robin DNS mentioned above. Just make sure the security rules are tight and not allowing external tampering with your log data. If you are not running a graylog cluster (which I won’t cover), then the single instance can potentially fail. That isn’t a great loss, as log messages can be obtained from the instances, and they are short-lived anyway. But the metadata of the web interface is important – dashboards, alerts, etc. So it’s good to do regular backups (e.g. with mongodump). Using an EBS volume is also an option. Even though you send your log messages to the centralized log collector, it’s a good idea to also keep local logs, with the proper log rotation and cleanup. It’s not a trivial process, but it’s essential to have log collection, so I hope the guide has been helpful.

I've been playing around with Docker a lot lately. Many reasons for that, one for sure is, that I love to play around with latest technology and even help out to build a demo or two or a lab. The main difference, between what everybody else of my coworkers is doing is, that I run my setup on Windows. Like most of the middleware developers out there. So, If you followed Arun's blog about "Docker Machine to Setup Docker Host" you might have tried to make this work on windows already. Here is the ultimate short how-to guide on using Docker Machine to administrate and spin up your Docker hosts. Docker Machine Machine lets you create Docker hosts on your computer, on cloud providers, and inside your own data center. It creates servers, installs Docker on them, then configures the Docker client to talk to them. You basically don't have to have anything installed on your machine prior to this. Which is a hell lot easier, than having to manually install boot2docker before. So, let's try this out. You want to have at least one thing in place before starting with anything Docker or Machine. Go and get Git for Windows (aka msysgit). It has all kinds of helpful unix tools in his belly, which you need anyway. Prerequisites - The One For All Solution The first is to install the windows boot2docker distribution which I showed in an earlier blog. It contains the following bits configured and ready for you to use: - VirtualBox - Docker Windows Client Prerequisites- The Bits And Pieces I dislike the boot2docker installer for a variety of reasons. Mostly, because I want to know what exactly is going on on my machine. So I played around a bit and here is the bits and pieces installer if you decide against the one-for-all solution. Start with the virtualization solution. We need something like that on Windows, because it just can't run Linux and this is what Docker is based on. At least for now. So, get VirtualBox and ensure that version 4.3.18 is correctly installed on your system (VirtualBox-4.3.18-96516-Win.exe, 105 MB). WARNING: There is a strange issue, when you run Windows itself in Virtualbox. You might run into an issue with starting the host. And while you're at it, go and get the Docker Windows Client. The other is to grab the final from the test servers as a direct download (docker-1.6.0.exe, x86_64, 7.5MB). Rename to "docker" and put it into a folder of your choice (I assume it will be c:\docker\. Now you also need to download Docker Machine, which is another single executable (docker-machine_windows-amd64.exe, 11.5MB). Rename to "docker-machine" and put it into the same folder. Now add this folder to your PATH: set PATH=%PATH%;C:\docker If you change your standard PATH environment variable, this might safe your from a lot of typing. That's it. Now you're ready to create your first Machine managed Docker Host. Create Your Docker Host With Machine All you need is a simple command: docker-machine create --driver virtualbox dev And the output should state: ←[34mINFO←[0m[0000] Creating SSH key... ←[34mINFO←[0m[0001] Creating VirtualBox VM... ←[34mINFO←[0m[0016] Starting VirtualBox VM... ←[34mINFO←[0m[0022] Waiting for VM to start... ←[34mINFO←[0m[0076] "dev" has been created and is now the active machine. ←[34mINFO←[0m[0076] To point your Docker client at it, run this in your shell: eval "$(docker-machine.exe env dev)" This means, you just created a Docker Host using the VirtualBox provider and the name “dev”. Now you need to find out on which IP address the host is running. docker-machine ip 192.168.99.102 If you want to configure your environment variables, needed by the client more easy, just use the following command: docker-machine env dev export DOCKER_TLS_VERIFY=1 export DOCKER_CERT_PATH="C:\\Users\\markus\\.docker\\machine\\machines\\dev" export DOCKER_HOST=tcp://192.168.99.102:2376 Which outputs the Linux version of environment variable definition. All you have to do is to change the "export" keyword to "set", remove the " and the double back-slashes and you are ready to go. C:\Users\markus\Downloads>set DOCKER_TLS_VERIFY=1 C:\Users\markus\Downloads>set DOCKER_CERT_PATH=C:\Users\markus\.docker\machine\machines\dev C:\Users\markus\Downloads>set DOCKER_HOST=tcp://192.168.99.102:2376 Time to test our Docker Client And here we go now run WildFly on your freshly created host: docker run -it -p 8080:8080 jboss/wildfly Watch the container being downloaded and check, that it is running by redirecting your browser to http://192.168.99.102:8080/. Congratulations on having setup your very first docker host with Maschine on Windows.

In containers and microservices, we’re facing the greatest potential change in how we deliver and run software services since the arrival of virtual machines.

Article Purpose: The following article will suggest a solution for adding custom information to your web application using manifest.mf file and expose that information in API. The necessity for this solution came to solve "blindness" in deployment. in simpler words, I want to know what war i deployed, what build version it has and more useful information i might need. Since i exposed the information via API, this could function as application "health-check", so this is a nice little addition for the solution. Techs: war (your web application) mvn - build tool maven-war-plugin Jenkins job Step 1 - Adding maven war plugin First you should add the maven war plugin to your pom.xml. In the tag you should add the custom information you need. in case you want to use the default information the plugin gives you out of the box, just mark the value of as true. In the following example you can see i added fields like buildVersion, build time and so on. This build tool is going to provide this data, in this case jenkins. org.apache.maven.plugins maven-war-plugin false ${project.version} ${build.number} ${maven.build.timestamp} ${agent.name} ${user.name} ${[yourWarName].war.finalName} Step 2 - Define maven variables The properties you want to add should be provided from "out side", you should add variables in your pom so Jenkins assign the values there. In the following example below, you can see the build.number variable i defined in the previous step. SNAPSHOT Step 3 - Adding maven goals to your Jenkins job definitions Jenkins has available environment variables you can pass to the maven goal, such as BUILD_NUMBER, BUILD_ID and so on. assign the Jenkins variable to the maven variable in the build step. when Jenkins is going to build the code, it going to sign the manifest,mf file with the custom information we wanted. Step 4 - Exposing the information of war We did all this hard work for one purpose. so we will have this information available in deployment stage. you should expose via API this information. in this example i used Spring MVC controller, and mapped the data to json format but you can have your pick. package your.package; @Controller @RequestMapping(value = "/version", produces = MediaType.APPLICATION_JSON_VALUE) public class VersionController { @Autowired ApplicationContext applicationContext; @RequestMapping(method = RequestMethod.GET) @ResponseBody public JSONObject getVersion() { JSONObject result = new JSONObject(); Resource resource = applicationContext.getResource("/META-INF/MANIFEST.MF"); try { Manifest manifest = new Manifest(resource.getInputStream()); if (manifest != null){ Attributes mainAttributes = manifest.getMainAttributes(); if(mainAttributes != null){ for (Object key : mainAttributes.keySet()) { result.put(key, mainAttributes.get(key)); } } } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return result; } } Step 5 - Enjoy :)

Examples Windows: netbeans.exe --userdir C:\MyOtherUserdir --cachedir "%HOME%\Locale Settings\Application Data\NetBeans\7.1\cache" Unix: ./netbeans --userdir ~/my-other-userdir Mac OS: /Applications/NetBeans.app/Contents/MacOS/executable --userdir ~/my-other-userdir Ref: http://wiki.netbeans.org/FaqAlternateUserdir

The easiest way to import data from relational or legacy systems, like plain CSV files without headers, into Neo4j with Cypher and a graph model.

When testing an application or service, it can be very useful to simulate degraded network conditions. This allows you to see how they might perform for users.

The nice thing about Gradle is that we can use Java libraries in our build script. This way we can add extra functionality to our build script in an easy way. We must use the classpath dependency configuration for our build script to include the library. For example we can include the library Grgit, which provides an easy way to interact with Git from Java or Groovy code. This library is also the basis for the Gradle Git plugin. In the next example build file we add the Grgit library to our build script classpath. Then we use the open method of the Grgit class. From the returned object we invoke the head to get the commit id identified as id. With the abbreviatedId property we get the shorter version of the Git commit id. The build file also includes the application plugin. We customize the applicationDistribution CopySpec from the plugin and expand the properties in a VERSION file. This way our distribution always includes a plain text file VERSION with the Git commit id of the code. buildscript { repositories { jcenter() } dependencies { // Add dependency for build script, // so we can access Git from our // build script. classpath 'org.ajoberstar:grgit:1.1.0' } } apply plugin: 'java' apply plugin: 'application' ext { // Open the Git repository in the current directory. git = org.ajoberstar.grgit.Grgit.open(file('.')) // Get commit id of HEAD. revision = git.head().id // Alternative is using abbreviatedId of head() method. // revision = git.head().abbreviatedId } // Use abbreviatedId commit id in the version. version = "2.0.1.${git.head().abbreviatedId}" // application plugin extension properties. mainClassName = 'sample.Hello' applicationName = 'sample' // Customize applicationDistribution // CopySpec from application plugin extension. applicationDistribution.with { from('src/dist') { include 'VERSION' expand( buildDate: new Date(), // Use revision with Git commit id: revision : revision, version : project.version, appName : applicationName) } } // Contents for src/dist/VERSION: /* Version: ${version} Revision: ${revision} Build-date: ${buildDate.format('dd-MM-yyyy HH:mm:ss')} Application-name: ${appName} */ assemble.dependsOn installDist When we run the build task for our project we get the following contents in our VERSION file: Version: 2.0.1.e2ab261 Revision: e2ab2614011ff4be18c03e4dc1f86ab9ec565e6c Build-date: 22-04-2015 13:53:31 Application-name: sample Written with Gradle 2.3.