On Fri, Mar 2, 2012 at 4:10 PM, Monsyne Dragon <mdra...@rackspace.com> wrote: > > On Mar 2, 2012, at 9:17 AM, Jay Pipes wrote: > >> On 03/02/2012 05:34 AM, Day, Phil wrote: >>> In our experience (running clusters of several hundred nodes) the DB >>> performance is not generally the significant factor, so making its calls >>> non-blocking gives only a very small increase in processing capacity and >>> creates other side effects in terms of slowing all eventlets down as they >>> wait for their turn to run. >> >> Yes, I believe I said that this was the case at the last design summit -- or >> rather, I believe I said "is there any evidence that the database is a >> performance or scalability problem at all"? >> >>> That shouldn't really be surprising given that the Nova DB is pretty small >>> and MySQL is a pretty good DB - throw reasonable hardware at the DB server >>> and give it a bit of TLC from a DBA (remove deleted entries from the DB, >>> add indexes where the slow query log tells you to, etc) and it shouldn't be >>> the bottleneck in the system for performance or scalability. >> >> ++ >> >>> We use the python driver and have experimented with allowing the eventlet >>> code to make the db calls non-blocking (its not the default setting), and >>> it works, but didn't give us any significant advantage. >> >> Yep, identical results to the work that Mark Washenberger did on the same >> subject. >> > > Has anyone thought about switching to gevent? It's similar enough to > eventlet that the port shouldn't be too bad, and because it's event loop is > in C, (libevent), there are C mysql drivers (ultramysql) that will work with > it without blocking.
We've been exploring this possibility at DreamHost, and chatted with some other stackers about it at various meat-space venues. Fwiw, it's something we'd be very interested in supporting (starting with as much test coverage as possible of eventlet's current use in OpenStack, to ensure as pain-free a transition as possible). d _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
