Hi Quantum folks This bp for nova looks like solve the quantum one also. https://blueprints.launchpad.net/nova/+spec/non-blocking-db 2012/12/3 Nachi Ueno <nachi at nttmcl.com> > Hi Quantum folks > > I faced the problem with mysql transaction and eventlet. > > Quantum using transaction support of sqlalchemy > Quantum also using eventlet for RPC > > Let's say there are api request A and B. > Sql request of A will lock B's sql request. > so B's sql request will wait the A's transaction. > > On the other hand, we are using evenetlet. > Since we are using mysql c client, the API request may block eventlet > thread. > > so when B start wait sql lock, it blocks all eventlet thread including api > request A until lock timeout. > > I asked Jay about the this problem, and he said Nova solve this problem by > this way. > > https://github.com/openstack/nova/blob/master/nova/db/sqlalchemy/api.py#L2610 > > The strategy is to get lock just after the transaction started using. ( > I'm not sure we can use same strategy in the quantum. ) > > Anyway, It looks big change needed for me. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20121203/62afc6b7/attachment.html>