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/20121203/68db8db6/attachment.html>