[ovirt-devel] Doctor Rest PostgreSQL report

Thu Oct 1 15:21:51 UTC 2015

----- Original Message -----
> From: "Piotr Kliczewski" <pkliczew at redhat.com>
> To: "Martin Betak" <mbetak at redhat.com>
> Cc: "engine-devel at ovirt.org" <devel at ovirt.org>
> Sent: Thursday, October 1, 2015 5:08:39 PM
> Subject: Re: [ovirt-devel] Doctor Rest PostgreSQL report
> 
> Martin,
> 
> Looking at the stats you generated I can see that there is almost no
> difference for cpu and memory. Load seems to be at the same level for both.
> I tried to understand the differences by looking and # of calls and total
> time (top 10) but there was almost no difference. The only slight difference
> I can see is in avg time. It seems that we haven't generate enough load to
> see significant improvement. How many client have you used during testing?

This benchmark was without any clients. This was just to demonstrate the load
Doctor generates on DB in context of existing DB load by backend (mosty VM/Host
monitoring), which was I believe one of Barak's major concerns: how expensive it
is when we *don't* have thousands of connected users. 

> 
> I am not sure how much it would take but what do you think about using
> doctor as caching service for the engine and run few tests.
> I wonder what would be the result of such PoC.

I would like to move to more real world tests as soon as we have at least 
some working prototype of next gen UI (most significantly the new Dashboard).

I understand that the UI discussions (adding Vojtech to CC) have progressed
recently so as soon as we have some actual frontend code to work with I would
like to hook it up to Doctor and make some end-to-end measurements.

Martin

> 
> Thanks,
> Piotr
> 
> 
> On Thu, Oct 1, 2015 at 3:25 PM, Martin Betak <mbetak at redhat.com> wrote:
> 
> > Hi All,
> >
> > so I installed a few more plugins to the pgCluu and PostgreSQL itself.
> > Now I have also the overall system load and total numbers for specific
> > queries.
> >
> > If you look at the report, database 'engine' and 'Statement statistics'
> > we can clearly see that the overwhelming majority of DB time is spent in
> > GetVmsRunningOnVds() stored procedure.
> >
> > Turining on Doctor Rest with 5 second full-dump interval you can see
> > that the calls used by DoctorCacheManager (GetAllFromVms,
> > GetAllFromVds....)
> > have hard time to add up to at least 1% of the overall load.
> >
> > Also you can see the 'System': CPU and memory statistics that those are
> > largely
> > unaffected by running Doctor service alongside engine.
> >
> > I also tried setting the full update interval to Doctor to 1 second to see
> > how
> > this would go - so essentially each second do a full dump of business
> > entities -
> > and this moved the overall Doctor overhead to ~2.5% of total DB load.
> >
> > Of course for the UI purposes interval in the range of 3-5 seconds should
> > be more
> > than acceptable in my opinion.
> >
> > As always - questions and remarks are more than welcome :-)
> >
> > Best regards,
> >
> > Martin
> >
> > ----- Original Message -----
> > > From: "Martin Betak" <mbetak at redhat.com>
> > > To: "Piotr Kliczewski" <pkliczew at redhat.com>
> > > Cc: "engine-devel at ovirt.org" <devel at ovirt.org>
> > > Sent: Wednesday, September 30, 2015 4:52:12 PM
> > > Subject: Re: [ovirt-devel] Doctor Rest PostgreSQL report
> > >
> > > ----- Original Message -----
> > > > From: "Piotr Kliczewski" <pkliczew at redhat.com>
> > > > To: "Martin Betak" <mbetak at redhat.com>
> > > > Cc: "engine-devel at ovirt.org" <devel at ovirt.org>, "Eli Mesika"
> > > > <emesika at redhat.com>, "Martin Perina"
> > > > <mperina at redhat.com>
> > > > Sent: Wednesday, September 30, 2015 3:29:28 PM
> > > > Subject: Re: Doctor Rest PostgreSQL report
> > > >
> > > > Martin,
> > > >
> > > > For me it would be great to understand how cpu, memory changes over
> > time
> > > > for the engine. I would like to see the same for doctor service.
> > > > I was not able to find it but it would be great to understand how many
> > > > queries there were for both tests and how log it took to run them.
> > >
> > > Yes, right now I'm looking for other tools to provide me exactly with
> > that.
> > > I just wanted to share the preliminary aggregated statistics.
> > >
> > > >
> > > > It would be good to understand implications of running doctor on the
> > same
> > > > machine as engine and on other machine.
> > > >
> > >
> > > Indeed, this is precisely what I'm testing. The attached reports were
> > with
> > > Doctor running on the same machine as the engine.
> > >
> > > > Thanks,
> > > > Piotr
> > > >
> > > >
> > > > On Wed, Sep 30, 2015 at 3:13 PM, Martin Betak <mbetak at redhat.com>
> > wrote:
> > > >
> > > > > Hi All,
> > > > >
> > > > > I performed a stress test using FakeVDSM environment with 200+ hosts
> > > > > and 500+ VMs.
> > > > >
> > > > > Attached are generated HTML reports for this environment.
> > > > > In both cases I tried to simulate some random load using existing
> > > > > webadmin. In the '_doctor' case the simple connector from [1] was
> > > > > running *in addition to* the legacy UI.
> > > > >
> > > > > The used pgCluu tool [2] which may be useful
> > > > > for DB experts for some further insight.
> > > > >
> > > > > I wanted to send this out as soon as possible so we can better
> > analyze
> > > > > our current performance and the possible impact Doctor Rest
> > > > > integration would have on the system.
> > > > >
> > > > > Please feel free to review the attached reports and/or suggest other
> > > > > ways/tools how to better benchmark the DB load caused by Doctor Rest.
> > > > >
> > > > > Thank you very much.
> > > > >
> > > > > Best regards
> > > > >
> > > > > Martin
> > > > >
> > > > > [1] https://gerrit.ovirt.org/#/c/45233/
> > > > > [2] http://pgcluu.darold.net/
> > > >
> > > _______________________________________________
> > > Devel mailing list
> > > Devel at ovirt.org
> > > http://lists.ovirt.org/mailman/listinfo/devel
> > >
> >
> 