Open Stack

On 09/14/2016 09:15 AM, Sean Dague wrote:
> I noticed the following issues happening quite often now in the
> opportunistic db tests for nova -
> http://logstash.openstack.org/#dashboard/file/logstash.json?query=message%3A%5C%22sqlalchemy.exc.ResourceClosedError%5C%22
>
>
> It looks like some race has been introduced where the various db
> connections are not fully isolated from each other like they used to be.
> The testing magic for this is buried pretty deep in oslo.db.

that error message occurs when a connection that is intended against a 
SELECT statement fails to provide a cursor.description attribute.  It is 
typically a driver-level bug in the MySQL world and corresponds to 
mis-handled failure modes from the MySQL connection.

By "various DB connections are not fully isolated from each other" are 
you suggesting that a single in-Python connection object itself is being 
shared among multiple greenlets?   I'm not aware of a change in oslo.db 
that would be a relationship to such an effect.



>
> Olso.db 4.13.3 did hit the scene about the time this showed up. So I
> think we need to strongly consider blocking it and revisiting these
> issues post newton.
>
> 	-Sean
>