On Jan 29, 2015, at 8:57 AM, Roman Podoliaka <rpodoly...@mirantis.com> wrote:
> Jeremy, > > I don't have exact numbers, so yeah, it's just an assumption based on > looking at the nova-api/scheduler logs with connection_debug set to > 100. > > But that's a good point you are making here: it will be interesting to > see what difference enabling of PyMySQL will make for tempest/rally > workloads, rather than just running synthetic tests. I'm going to give > it a try on my devstack installation. FWIW I tested this a while ago on some perf tests on nova and cinder that we run internally and I found pymysql to be slower by about 10%. It appears that we were cpu bound in python more often than we were blocking talking to the db. I do recall someone doing a similar test in neutron saw some speedup, however. On our side we also exposed a few race conditions which made it less stable. We hit a few hard deadlocks in volume create IIRC. I don’t think switching is going to give us much benefit right away. We will need a few optimizations and bugfixes in other areas (particularly in our sqlalchemy usage) before we will derive any benefit from the switch. Vish > > Thanks, > Roman > > On Thu, Jan 29, 2015 at 6:42 PM, Jeremy Stanley <fu...@yuggoth.org> wrote: >> On 2015-01-29 18:35:20 +0200 (+0200), Roman Podoliaka wrote: >> [...] >>> Otherwise, PyMySQL would be much slower than MySQL-Python for the >>> typical SQL queries we do (e.g. ask for *a lot* of data from the DB). >> [...] >> >> Is this assertion based on representative empirical testing (for >> example profiling devstack+tempest, or perhaps comparing rally >> benchmarks), or merely an assumption which still needs validating? >> -- >> Jeremy Stanley >> >> __________________________________________________________________________ >> 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 > > __________________________________________________________________________ > 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 __________________________________________________________________________ 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