[openstack-dev] [Ceilometer][QA][Tempest][Infra] Ceilometer tempest testing in gate

Alexei Kornienko alexei.kornienko at gmail.com
Fri Mar 21 17:37:24 UTC 2014


Hello,

As promised I'm sharing results for PostgreSQL and MongoDB (attached).
Please note that numbers are a bit different since MongoDB contains 
results collected during 4,5 hours and PostgreSQL only for 1 hour.

As expected PostgreSQL shows results similar with MySQL (since amount of 
rollbacks is the same). It created a high cpu load on 
ceilometer-collector (~85%) and psql (~100%) processes.

results with MongoDB are much better: collector consumes 5-30% cpu and 
prof shows that profiling overhead becomes visible and cpu spends a lot 
of time in _lsprof.so.

Cause of this results I wonder what licensing problems we have in 
promoting MongoDB as prefered/default storage?
I've read AGPL license trying to understand your reasoning against it 
but I cannot find anything that can be potentially dangerous (since we 
are not modifying MongoDB itself).
Could you please tell me if I'm wrong and point me to the right place?

Regards.

On 03/21/2014 05:58 PM, Doug Hellmann wrote:
>
>
>
> On Fri, Mar 21, 2014 at 7:04 AM, Sean Dague <sean at dague.net 
> <mailto:sean at 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.kornienko at gmail.com <mailto:alexei.kornienko at gmail.com>
>     <mailto:alexei.kornienko at gmail.com
>     <mailto:alexei.kornienko at 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.
>
> Doug
>
>
>             -Sean
>
>     --
>     Sean Dague
>     Samsung Research America
>     sean at dague.net <mailto:sean at dague.net> / sean.dague at samsung.com
>     <mailto:sean.dague at samsung.com>
>     http://dague.net
>
>
>     _______________________________________________
>     OpenStack-dev mailing list
>     OpenStack-dev at lists.openstack.org
>     <mailto:OpenStack-dev at lists.openstack.org>
>     http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>
>
>
>
> _______________________________________________
> OpenStack-dev mailing list
> OpenStack-dev at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20140321/6643c983/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ceilometer-mongodb.dot
Type: application/msword-template
Size: 26890 bytes
Desc: not available
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20140321/6643c983/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: summary-pgsql.dot
Type: application/msword-template
Size: 74614 bytes
Desc: not available
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20140321/6643c983/attachment-0001.bin>


More information about the OpenStack-dev mailing list