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Showing posts from August, 2014

Elements of PaaS

PaaS (Platform as a Service) is a layer over IaaS (Infrastructure as a Service) that provides the following:
Some kind of deployement interfacecoupled with a load balancer - HAProxya service provisioning system Scalingin/out supportOptional add-on services: Backup and restore service PatchingCaching or data grid serviceDifferent DB types - relational, in-memory, no-sql 

The above is generally controlled by a service management layer that exposes all of the above operations of PaaS as REST endpoints. The implementation of the endpoints will use IaaS service endpoints to perform infrastructure related operations (like say adding/removing a VM etc).
Generally some devops toolkit like chef (solo)/puppet combined with some bash scripts are used to provision the platform (like say application server or database server) in the VM after the VM has been created.
The tenant user can either use the REST endpoints directly or through some SDK or CLI or through a web UI to request say, …

Understanding Heroku

Based on - https://devcenter.heroku.com/articles/how-heroku-works
Deploy, run and manage Java application on Heroku: Application = source code for application + web or application server framework + dependencies on third party libraries + dependency description (pom.xml) that instructs a build system (maven) to download the needed dependencies from a repository in order to build the application + Procfile.Procfile - lists named commands that you may want executed.
web: java -jar lib/foobar.jar $PORT
queuty: java -jar lib/queue-processor.jar
Defines a 'web' process type and provides a command that needs to be executed in order to run it. Git - used as primary means for deploying applications on Heroku platform. When application is created on Heroku, a new git remote is associated typically named "heroku" with the local git repository for your application. To deploy, simply do a git push heroku master. Thus git acts …

Book Review: The Giver by Lois Lowry

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** spoiler alert ** The Giver is a science fiction about a special community which has attained a very peaceful and strictly disciplined lifestyle for its citizens by enforcing rules and cutting them off from any and all randomness of life. Everything is controlled - population, feelings, freedom to choose their own job. It makes one think about what living in such a time will be like where people just don't feel anything wrong in killing (called releasing in the book) because they have never thought about releasing being bad - as it is what they have learned to expect by living in their community. We can compare this kind of feeling with our times and come up with a lot of aspects in our lives that we believe are bad today but were being practiced just a few years ago by some communities. Overall a thought provoking story. I am looking forward to read the other books in this series.