As discussed on the Cinder channel, I’ve opened https://bugs.launchpad.net/oslo.db/+bug/1692956 to see if oslo.db would be a good place to produce a warning when it detects this potential misconfiguration. Cheers, Arne On 23 May 2017, at 17:25, Sean McGinnis <sean.mcginnis at gmx.com<mailto:sean.mcginnis at gmx.com>> wrote: Just wanted to put this out there to hopefully spread awareness and prevent it from happening more. We had a bug reported in Cinder of hitting a deadlock when attempting to deelte multiple volumes simultaneously: https://bugs.launchpad.net/cinder/+bug/1685818 Some were seeing it, but others were not able to reproduce the error in their environments. What it came down to is the use of "mysql://" vs "mysql+pymysql://" for the database connection string. Big thanks to Gerhard Muntingh for noticing this difference. Basically, when using "mysql://" for the connection string, that uses blocking calls that prevent other "threads" from running at the same time, causing these deadlocks. This doesn't just impact Cinder, so I wanted to get the word out that it may be worth checking your configurations and make sure you are using "mysql+pymysql://" for your connections. Sean _______________________________________________ OpenStack-operators mailing list OpenStack-operators at lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators -- Arne Wiebalck CERN IT -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-operators/attachments/20170523/fea2a305/attachment.html>