Re: [ovirt-devel] Chaning the statistics monitoring interval to 30s

-- SHIRLY RADCO BI SOFTWARE ENGINEER, Red Hat Israel <https://www.redhat.com/> sradco(a)redhat.com <https://red.ht/sig> <https://redhat.com/summit> On Wed, Jul 5, 2017 at 6:35 PM, Arik Hadas <ahadas(a)redhat.com&gt; wrote: > > > On Wed, Jul 5, 2017 at 5:57 PM, Roy Golan <rgolan(a)redhat.com&gt; wrote: > >> Hi all, >> >> I would like to get feedback on $subject and see if I'm missing >> something. The impact of this is simply less resource consumption and by >> that we can support even greater number of hosts [1] and vms in the system. >> > >> If you think more relaxed statistics collection will affect a core flow >> let me know - as far as I see I didn't spot anything critical. >> > >> The overhead of a cycle per host something like that: 2 roundtrips per >> host in a cycle, (vm + host stats) and tons of memory allocation for char[] >> -> json-> maps of maps -> VM/Vds statistics -> Maps -> serialiazing to DB. >> >> To minimize the effect of this change we can leave a call to 'list' verb >> to at least detect vms existence in the same rate as today. >> > > +1 > > >> >> Pros >> - Engine has rore resources to support more hosts/vms/other activities >> of the engine >> - Vdsm will have more resources as well (need to tweak vdsm to collect >> in the same >> frequency) >> - less DB writes and reads, approx half of what the system will do in >> the in its lifefpan (cause this is what is mainly does all the time) >> >> Cons >> - DWH/Dashboard will have less entries, I'm not sure what is graphical >> affect given our hourly resolution (cmiiw here) >> > > What's the frequency of the queries done by DWH/Dashboard? Do they count > on the _update_date column of the queried data? > Current frequency is 20 seconds. The configurations are queried based on the _update_date, but statistics are queried every interval. The affect will be less accuracy in the hourly calculations.

> I'm asking because if they query the database every minute and say "the > time now is 10:30 and the queried data is ..." then there should not be > less entries. > > >> >> >> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1430876 >> > >> >> _______________________________________________ >> Devel mailing list >> Devel(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/devel >> > > > _______________________________________________ > Devel mailing list > Devel(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/devel >