Preventing Mongrel/Mysql Errno::EPIPE exceptions

Rails
1

I have a rails app serving up XML on an infrequent basis. This is being
run with mongrel and mysql. I’ve found that if the app does not get
exercised for longer than a few hours it goes dead (“Lost Connection to
MySQL”) and starts throwing Errno::EPIPE errors. It seems that the mysql
connection gets 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?

– Mike B.

2

On Sep 27, 12:43 am, Mike B. [email protected]
wrote:

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?

change the value of config.active_record.verification_timeout to
something below whatever timeout your mysql timeout is set to.

Fred

3

Frederick C. wrote:

change the value of config.active_record.verification_timeout to
something below whatever timeout your mysql timeout is set to.

It was also suggested elsewhere

that I do the following:
(full advice is at
https://boxpanel.blueboxgrp.com/public/the_vault/index.php/Mongrel_/_MySQL_Timeout
)

Set the verification timeout so that the mongrel connection won’t die

if left alone (1 week)
ActiveRecord::Base.verification_timeout = 604800

Keep Connection Open

Thread.new {
loop {
ActiveRecord::Base.verify_active_connections!;
1800.times { sleep 2 }
}
}.priority = -10

and also (in mysql.cnf)

Fix for bug where mongrel doesn’t close timed-out connections: Just

don’t time out connections.
wait_timeout= 3456000

Why is that thread calling verify_active_connections! needed if
verification_timeout < wait_timeout ?
– Mike B.