On 04/20 09:40, David Caro wrote:
> On 04/20 10:25, Eyal Edri wrote:
> > On Wed, Apr 20, 2016 at 10:20 AM, Barak Korren <bkorren@redhat.com> wrote:
> >
> > > On 20 April 2016 at 10:16, Eyal Edri <eedri@redhat.com> wrote:
> > > >
> > > >
> > > > On Wed, Apr 20, 2016 at 9:28 AM, Barak Korren <bkorren@redhat.com>
> > > wrote:
> > > >>
> > > >> > I'd try that approach first, though the mirror is a good idea that
> > > will
> > > >> > probably have to be implemented anyhow once we start adding slaves,
> > > >> > having real
> > > >> > info on the network usage/errors will give us insight to actually
> > > >> > determine
> > > >> > what's the issue, and thus, what's the best solution.
> > > >> >
> > > >> > @infra what do you think?
> > > >> >
> > > >>
> > > >> The issue with mirroring is how can you make sure that you mirror fast
> > > >> enough to enable CI. Even if Gerrit can push to the mirror on patch
> > > >> submission, there will still be some time delta between the submission
> > > >> happening (and the patch event showing up in Jenins) and the mirror
> > > >> being synced. This looks like a nasty race condition.
> > > >> What the mirror essentially does is make sure that bits are copied
> > > >> from Amazom to PHX just once. I wonder if we can get the same benefit
> > > >> with a simple HTTP proxy, how proxy-able is the Git HTTP protocol?
> > > >>
> > > >
> > > > I think we should prioritize mirroring the GIT (not gerrit) repos to PHX,
> > > > this will help:
> > > >
> > > > Speed up all post merge jobs and reduce potential of errors from git
> > > clone
> > > > (they will be in the same network)
> > > > Reduce load (?) from the gerrit server and perhaps reduce errors of the
> > > per
> > > > patch jobs that will still run from gerrit.ovirt.org (AMAZON)
> > > > A longer goal will be either to migrate the gerrit server to PHX or to
> > > find
> > > > away to properly mirror the gerrit server (but then i fear there might be
> > > > race/problem as mentioned)
> > > >
> > >
> > > Please look at my comment about possible race conditions caused by
> > > mirroring. Simple mirroring may cause more trouble then its worth. We
> > > need to consider proxying instead.
> > >
> >
> > I don't see how a race condition can occur with a merge commit,
> > Can you elaborate?
>
>
> From the gerrit config on jenkins:
>
>
> Replication cache expiration time in minutes
>
> If one of the server supports replication events, these events are cached in memory because they can be received before the build is triggered and this plugin gets called to evaluate if the build can run. Cache allows the plugin to look if the replication events were already received when it gets called to evaluate if the build can run. If the time elapsed between this plugin gets called and the time the build entered the queue is greated than the cache expiration time, the plugin will assume that replication events were received and will let the build run.
>
> Changing this value will only take effect when Jenkins is restarted
>

And from the specific server options:

Block builds in the queue until the replication events for the configured Gerrit slave(s) are received.

>
> >
> >
> >
> >
> > --
> > Eyal Edri
> > Associate Manager
> > RHEV DevOps
> > EMEA ENG Virtualization R&D
> > Red Hat Israel
> >
> > phone: +972-9-7692018
> > irc: eedri (on #tlv #rhev-dev #rhev-integ)
>
> --
> David Caro
>
> Red Hat S.L.
> Continuous Integration Engineer - EMEA ENG Virtualization R&D
>
> Tel.: +420 532 294 605
> Email: dcaro@redhat.com
> IRC: dcaro|dcaroest@{freenode|oftc|redhat}
> Web: www.redhat.com
> RHT Global #: 82-62605



--
David Caro

Red Hat S.L.
Continuous Integration Engineer - EMEA ENG Virtualization R&D

Tel.: +420 532 294 605
Email: dcaro@redhat.com
IRC: dcaro|dcaroest@{freenode|oftc|redhat}
Web: www.redhat.com
RHT Global #: 82-62605