A great experience while interacting with the ruby community from different places. Lots of knowledge and inspiration flows. Met many folks from india and abroad.
So the issue was, amazon issued an warning regarding the server to be terminated, before i could think of making an backup the instance stopped. The troubleshoot operations like reboot, stop and start didn't worked. Simple Steps to start a fresh instance with the previous content on server.
When you try to ssh into a instance and it failed giving errors which says remote host identification changed, possibly you have tried to ssh into that earlier but either it's been mapped to a IP or dns name has been assigned to that instance.you can resolve this issue ..
ActionView::Template::Error (Cannot allocate memory - nodejs /tmp/execjs20131021-26716-fckzo3.js 2>&1 Nodejs is used to compile javascript at runtime. In RoR applications, this error comes when server is started in production mode which compiles the assets or while running rake assets:precompile . check for swap space and allocate
Queries being executed along with time and space complexity helps to optimise database in the best possible ways. Though this topic has been covered vastly, i will pull the very basic ones for the beginners.
We often have to interact with linux servers over remote m/c's for deployment or maintenance issues. I would specify very basic commands which comes handy few times .
Error: couldn't connect to server 127.0.0.1:27017 src/mongo/shell/mongo.js:91 exception: connect failed check the /etc/mongodb.conf look for dbpath no go to that folder, by default it is /var/lib/mongodb . Remove the .lock file and then start mongodb
MongoDB setup with ec2 instances, odd no of ec2 instances should be used which helps in polling when the instances are down. Backup and restore will be easily managed when ebs storage volume is used and mongodb is setup on a independent instance.