Category Archives: HOWTO

My MongoDB cheatsheet

Few years ago, I was working on one mongoDB project.Its a NoSQL database , easy to learn and its pure JSON based. I learned it myself and had created a cheatsheet for it, so I can easily recall it anytime … Continue reading

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chef attribute : avoiding “undefined method `[]’ for nil:NilClass” error

In chef, when a nested attribute that might not exist/or not crated yet, you can use rescue as a modifier to an if statement. For example, assuming that only some of your nodes have node[‘install_wls’][‘isManaged’]defined: if node[‘install_wls’][‘isManaged’] do the stuff … Continue reading

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chef knife tricks: Add a node in an environment

  Sometime during automation of a large deployment process, we have to bootstrap a node , create environment and add the node in that particular environment on the fly.   Bootstraping : 2. Create environment dynamically from inside the programme:(python … Continue reading

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Chef Recipe: Oracle DB 11gR2 EE silent deploy

Chef provides a lot of flexibility and greater choice for infrastructure automation and I prefer it over others. We should design our recipe in such a way that the our recipes without being modified can be used in any environment … Continue reading

Posted in ARTICLES, DevOps, HOWTO, Operations, Private Cloud, Programming, Public Cloud, TUTORIALS | Tagged , , , | Leave a comment

Docker Supervisord – Way to run multiple Demon process in a container

The docker was released keeping in mind, one daemon  per container which makes the container lightweight. Like suppose for running a web application, one container will serve database, one container will server as web server, one container  will server as  caching … Continue reading

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xend Error: Acquire running lock failed: 256

Recently I encountered this issue in OVMM 3.2.9  while starting a vm with xm create <vm.cfg path> The reason behind this found was : the vm was not shutdown properly  and the lock file is still there even if VM … Continue reading

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xend issue : Xend has probably crashed! Invalid or missing HTTP status code.

I recently found  some VMs of one OVS node( from 30+ nodes)  went down and not able to start with this error : Xend has probably crashed!  Invalid or missing HTTP status code. There are many reasons behind this. And … Continue reading

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