The standard python postgresql driver (psycopg2) does have an async mode. There are non db api compliant async mysql drivers for gevent.
Excerpts from Vishvananda Ishaya's message of 2012-03-01 15:36:43 -0500: > Yes it does. We actually tried to use a pool at diablo release and it was > very broken. There was discussion about moving over to a pure-python mysql > library, but it hasn't been tried yet. > > Vish > > On Mar 1, 2012, at 11:45 AM, Yun Mao wrote: > > > There are plenty eventlet discussion recently but I'll stick my > > question to this thread, although it's pretty much a separate > > question. :) > > > > How is MySQL access handled in eventlet? Presumably it's external C > > library so it's not going to be monkey patched. Does that make every > > db access call a blocking call? Thanks, > > > > Yun > > > > On Wed, Feb 29, 2012 at 9:18 PM, Johannes Erdfelt <johan...@erdfelt.com> > > wrote: > >> On Wed, Feb 29, 2012, Yun Mao <yun...@gmail.com> wrote: > >>> Thanks for the explanation. Let me see if I understand this. > >>> > >>> 1. Eventlet will never have this problem if there is only 1 OS thread > >>> -- let's call it main thread. > >> > >> In fact, that's exactly what Python calls it :) > >> > >>> 2. In Nova, there is only 1 OS thread unless you use xenapi and/or the > >>> virt/firewall driver. > >>> 3. The python logging module uses locks. Because of the monkey patch, > >>> those locks are actually eventlet or "green" locks and may trigger a > >>> green thread context switch. > >>> > >>> Based on 1-3, does it make sense to say that in the other OS threads > >>> (i.e. not main thread), if logging (plus other pure python library > >>> code involving locking) is never used, and we do not run a eventlet > >>> hub at all, we should never see this problem? > >> > >> That should be correct. I'd have to double check all of the monkey > >> patching that eventlet does to make sure there aren't other cases where > >> you may inadvertently use eventlet primitives across real threads. > >> > >> JE > >> > >> > >> _______________________________________________ > >> Mailing list: https://launchpad.net/~openstack > >> Post to : openstack@lists.launchpad.net > >> Unsubscribe : https://launchpad.net/~openstack > >> More help : https://help.launchpad.net/ListHelp > > > > _______________________________________________ > > Mailing list: https://launchpad.net/~openstack > > Post to : openstack@lists.launchpad.net > > Unsubscribe : https://launchpad.net/~openstack > > More help : https://help.launchpad.net/ListHelp > _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
