Hi Josh, On Mon, Mar 7, 2016 at 5:25 PM, Joshua Hesketh <[email protected]> wrote: > Hi Mikhail, > > Thank you for the extra details. I'll continue to look into this. > > With the daily bumps when you do the log rotation, I assume you aren't > reloading zuul at that point and the freed memory is likely due to another > process?
I was puzzled by the bumps, and checked the syslog. They are definitely due to "run-parts --report /etc/cron.daily" being triggered at 06:25, and not zuul reloads. The memory bumps could be due to any of the cron jobs. logrotate seemed likely. For the record: root@zuul:~# ls /etc/cron.daily apache2 apport apt aptitude bsdmainutils dpkg exim4-base logrotate man-db mlocate ntp passwd update-notifier-common upstart I have also confirmed there were no changes to zuul layout for the interval that the graph shows. > > Cheers, > Josh > > On Tue, Mar 8, 2016 at 10:17 AM, Mikhail Medvedev <[email protected]> > wrote: >> >> On Wed, Feb 10, 2016 at 10:57 AM, James E. Blair <[email protected]> >> wrote: >> > Michael Still <[email protected]> writes: >> > >> >> On Tue, Feb 9, 2016 at 4:59 AM, Joshua Hesketh >> >> <[email protected]> >> >> wrote: >> >> >> >>> On Thu, Feb 4, 2016 at 2:44 AM, James E. Blair <[email protected]> >> >>> wrote: >> >>>> >> >>>> On the subject of clearing the cache more often, I think we may not >> >>>> want >> >>>> to wipe out the cache more often than we do now -- in fact, I think >> >>>> we >> >>>> may want to look into ways to keep from doing even that, because >> >>>> whenever we reload now, Zuul slows down considerably as it has to >> >>>> query >> >>>> Gerrit again for all of the data previously in its cache. >> >>>> >> >>> >> >>> I can see a lot of 3rd parties or simpler CI's not needing to reload >> >>> zuul >> >>> very often so this cache would never get cleared. Perhaps cached >> >>> objects >> >>> should have an expiry time (of a day or so) and can be cleaned up >> >>> periodically? Additionally if clearing the cache on a reload is >> >>> causing >> >>> pain maybe we should move the cache into the scheduler and keep it >> >>> between >> >>> reloads? >> >>> >> >> >> >> Do you guys use oslo at all? I ask because the olso memcache stuff does >> >> exactly this, so it should be trivial to implement if you don't mind >> >> depending on oslo. >> > >> > One of the main things we use the cache for is to ensure that every >> > change is represented by a single Change object in Zuul's memory. The >> > graph of enqueued Items link to their respective Changes which may link >> > to each other due to dependencies. When something changes in Gerrit, we >> > want that reflected immediately and consistently in all of the objects >> > in that graph. Using the cache means that every time we add a new >> > Change object to that graph, we use the same object for a given change. >> > >> > This is why we can't use time-based expiry -- we must not drop objects >> > from the cache if they are still in the graph. Otherwise we will create >> > new duplicative objects and the ones still in the graph will not be >> > updated. >> > >> > Perhaps we should change these objects to something more ephemeral that >> > can proxy for some other mechanism that can operate more like a >> > traditional cache (with time-based expiry). But I think changes to this >> > system should happen in Zuulv3 -- it works well enough for Zuulv2 for >> > now. >> > >> > -Jim >> > >> >> We are one of third-party CIs and using "Zuul version: 2.1.1.dev123", >> which is one commit after [1]. That one commit after is not in tree - I am >> applying [2] on top. >> >> The VM has 8GB of RAM. zuul-server memory footprint goes up consistently >> over >> the course of a week. Normally it takes about 3-4 days to get over to 3Gb. >> About a week ago I witnessed zuul-server get to 95% of RAM, at which point >> kernel started killing other processes. The graph [3] memory [3], and it >> reflects zuul-server consumption. The daily bumps on the graph are daily >> cron >> doing log rotation etc, possibly flushing caches. >> >> I can not say 100% that it is still the leak. Could simply be that >> zuul-server >> requires more ram now. >> >> [1] >> https://review.openstack.org/#q,I81ee47524cda71a500c55a95a2280f491b1b63d9,n,z >> [2] >> https://review.openstack.org/#q,If3a418fa2d4993a149d454e02a9b26529e4b6825,n,z >> [3] http://imgur.com/SzqSA1H >> >> Mikhail Medvedev (mmedvede) >> >> _______________________________________________ >> OpenStack-Infra mailing list >> [email protected] >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-infra > > _______________________________________________ OpenStack-Infra mailing list [email protected] http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-infra
