Open Stack

On 07/09/2014 05:17 AM, Ihar Hrachyshka wrote:
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> Hi all,
>
> Multiple projects are suffering from db lock timeouts due to deadlocks
> deep in mysqldb library that we use to interact with mysql servers. In
> essence, the problem is due to missing eventlet support in mysqldb
> module, meaning when a db lock is encountered, the library does not
> yield to the next green thread, allowing other threads to eventually
> unlock the grabbed lock, and instead it just blocks the main thread,
> that eventually raises timeout exception (OperationalError).
>
> The failed operation is not retried, leaving failing request not
> served. In Nova, there is a special retry mechanism for deadlocks,
> though I think it's more a hack than a proper fix.

This may be a bit of a tangent to the original discussion, but does 
anyone know where we stand with postgres and eventlets?  Is pyscopg2 
susceptible to the same problems as mysqldb?

Chris