On 06/18/2015 03:47 PM, Mike Bayer wrote: > > > On 6/18/15 1:28 PM, Matt Riedemann wrote: >> >> >>> >> >> It's not only neutron, I saw some pymysql failures in nova the other >> day for 'too many connections' or some such related error. > > "too many connections" is an error raised by MySQL when more connections > are attempting to connect than the max_connections setting. It defaults > to 100 but it is often set at 1024 in distributions. An Openstack > application that uses oslo.db will go through oslo.db's create_engine() > routine which defaults the max number of connections per python process > to 15, and when the process is idle, this drops to 5. > > Which means, there have to be over 60 python processes all hitting the > DB at the max to get that error, if max_connections is at 1024. Or > the connection pool is totally broken (e.g. with eventlet monkeypatching > perhaps), which would be a critical issue for me to fix. > > So I'd love to see how the "too many connections" error actually > happens. Please share whatever you have on that.
I believe the distro defaults in Ubuntu are the mysql defaults, which is 151 - https://dev.mysql.com/doc/refman/5.5/en/too-many-connections.html If we're allowing 15 connections per python process, and the APIs are running in a worker mode, which means 8 workers per API server, yes, that's going to add up really quick. Perhaps under these scenarios we need to raise this to 1024 in devstack? -Sean -- Sean Dague http://dague.net __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev