I've ready many posts about this problem. My understanding is the Application has a setting which says how long to keep idle database connections before dropping them and creating new ones. MySQL has a setting that says how long to keep idle connections. After no site activity, MySQL times out the Application's connections. But the Application doesn't know this and still tries using an existing connection, which fails. After the failure the Application drops the connection and makes a new one, and then it is fine.
I have wait_timeout set to 10 seconds on my local mysql server. I have pool_recycle set to 5 seconds on my locally running application. After 10 seconds of inactivity, I make a request, and am still getting this error. Making another request afterwards within 10 seconds, it is then fine. Waiting longer than 10 seconds, it gives this error again.
Any thoughts?
mysql> SELECT @@global.wait_timeout\G
*************************** 1. row ***************************
@@global.wait_timeout: 10
1 row in set (0.00 sec)
.
sqlalchemy.twelvemt.pool_recycle = 5
.
engine = engine_from_config(settings, 'sqlalchemy.twelvemt.')
DBSession.configure(bind=engine)
.
OperationalError: (OperationalError) (2006, 'MySQL server has gone away') 'SELECT beaker_cache.data \nFROM beaker_cache \nWHERE beaker_cache.namespace = %s' ('7cd57e290c294c499e232f98354a1f70',)
It looks like the error you're getting is being thrown by your Beaker connection, not your DBSession connection-- the pool_recycle option needs to be set for each connection.
Assuming you're configuring Beaker in your x.ini file, you can pass sqlalchemy options via session.sa.*, so session.sa.pool_recycle = 5
See http://docs.pylonsproject.org/projects/pylons-webframework/en/v0.9.7/sessions.html#sa