Preventing Mongrel/Mysql Errno::EPIPE exceptions
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02-07-2019 - |
Question
I have a rails app that I have serving up XML on an infrequent basis. This is being run with mongrel and mysql. I've found that if I don't exercise the app for longer than a few hours it goes dead and starts throwing Errno::EPIPE errors. It seems that the mysql connection get timed out for inactivity or something like that.
It can be restarted with 'mongrel_rails restart -P /path/to/the/mongrel.pid' ... but that's not really a solution. My collaborator expects the app to be there when he is working on his part (and I am most likely not around).
My question is:
- What can I do to prevent this problem from occurring in the 1st place? (e.g. don't time me out!!).
- Failing that, is there some code I can insert somewhere to automatically remake the Db connection?
Solution
Here's a solution:
https://boxpanel.blueboxgrp.com/public/the_vault/index.php/Mongrel_/_MySQL_Timeout
The timeouts on the above solution seem a little high to me. You don't want your DB timeouts to be too low, because of the amount of memory a connection can use. If a connection is orphaned, you want it to time out reasonably (like not in one week.)
OTHER TIPS
In other places, I also got the following suggestions:
Try setting config.active_record.verification_timeout to something lower than whatever your mysql connection timeout setting is.
There's a gem to work around this problem: mysql_retry_lost_connection
http://rubyforge.org/projects/zventstools/ "Reconnect to the MySQL server when you hit a lost connection error".