I am having issues with tcp connections between two instances in EC2. I thought at first it was the tools I was using (JRuby on Rails stack + MongoDB) when I saw exceptions such as the following in my code:
A Mongo::OperationFailure occurred in foo#bar: Mongo::OperationFailure .bundle/jruby/1.8/gems/mongo-1.6.2/lib/mongo/util/tcp_socket.rb:76:in `read'
So thinking this is a software issue, I didn't come to ServerFault. I thought the IO classes in JRuby might be hosed after some research but that wasn't accurate. I went ahead and installed Ruby 1.9.3 and moved the entire stack over to it. Sure enough after a while, a similar exception creeped up:
A Errno::ETIMEDOUT occurred in anotherfoo#anotherbar: Connection timed out mongo (1.6.2) lib/mongo/util/tcp_socket.rb:70:in `readpartial'
The reason I come to serverfault for help is because I do believe this might be some inter zone timeout issue in Amazon's infrastructure and I was wondering if any can verify or give me suggestions for how to further debug this as I'm running out of solutions. My app server is in us-east-1a. The mongodb server is in us-east-1c. Perhaps that could be a reason? Why might I bet getting these timeouts using a default Amazon Linux AMI (64-bit, XLARGE)?