On Fri, Mar 21, 2014 at 5:13 PM, Joe Gordon <joe.gord...@gmail.com> wrote:
> > > > On Fri, Mar 21, 2014 at 8:58 AM, Doug Hellmann < > doug.hellm...@dreamhost.com> wrote: > >> >> >> >> On Fri, Mar 21, 2014 at 7:04 AM, Sean Dague <s...@dague.net> wrote: >> >>> On 03/20/2014 06:18 PM, Joe Gordon wrote: >>> > >>> > >>> > >>> > On Thu, Mar 20, 2014 at 3:03 PM, Alexei Kornienko >>> > <alexei.kornie...@gmail.com <mailto:alexei.kornie...@gmail.com>> >>> wrote: >>> > >>> > Hello, >>> > >>> > We've done some profiling and results are quite interesting: >>> > during 1,5 hour ceilometer inserted 59755 events (59755 calls to >>> > record_metering_data) >>> > this calls resulted in total 2591573 SQL queries. >>> > >>> > And the most interesting part is that 291569 queries were ROLLBACK >>> > queries. >>> > We do around 5 rollbacks to record a single event! >>> > >>> > I guess it means that MySQL backend is currently totally unusable >>> in >>> > production environment. >>> > >>> > >>> > It should be noticed that SQLAlchemy is horrible for performance, in >>> > nova we usually see sqlalchemy overheads of well over 10x (time >>> > nova.db.api call vs the time MySQL measures when slow log is recording >>> > everything). >>> >>> That's not really a fair assessment. Python object inflation takes time. >>> I do get that there is SQLA overhead here, but even if you trimmed it >>> out you would not get the the mysql query time. >>> >>> That being said, having Ceilometer's write path be highly tuned and not >>> use SQLA (and written for every back end natively) is probably >>> appropriate. >>> >> >> I have been working to get Mike Bayer (author of SQLAlchemy) to the >> summit in Atlanta. He is interested in working with us to improve >> SQLAlchemy, so if we have specific performance or feature issues like this, >> it would be good to make a list. If we have enough, maybe we can set aside >> a session in the Oslo track, otherwise we can at least have some hallway >> conversations. >> > > > That would be really amazing. Is he on IRC, so we can get the ball rolling? > I'll ask him to join #openstack-dev if he is. Doug > > >> >> Doug >> >> >> >>> >>> -Sean >>> >>> -- >>> Sean Dague >>> Samsung Research America >>> s...@dague.net / sean.da...@samsung.com >>> http://dague.net >>> >>> >>> _______________________________________________ >>> OpenStack-dev mailing list >>> OpenStack-dev@lists.openstack.org >>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >>> >>> >> >> _______________________________________________ >> OpenStack-dev mailing list >> OpenStack-dev@lists.openstack.org >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> >> > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > >
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