[openstack-dev] [Neutron] L3 agent rescheduling issue

Kevin Benton blak111 at gmail.com
Thu Jun 4 21:20:33 UTC 2015

After trying to reproduce this, I'm suspecting that the issue is actually
on the server side from failing to drain the agent report state queue in

I set the report_interval to 1 second on the agent and added a logging
statement and I see a report every 1 second even when sync_routers is
taking a really long time.

On Thu, Jun 4, 2015 at 11:52 AM, Carl Baldwin <carl at ecbaldwin.net> wrote:

> Ann,
> Thanks for bringing this up.  It has been on the shelf for a while now.
> Carl
> On Thu, Jun 4, 2015 at 8:54 AM, Salvatore Orlando <sorlando at nicira.com>
> wrote:
> > One reason for not sending the heartbeat from a separate greenthread
> could
> > be that the agent is already doing it [1].
> > The current proposed patch addresses the issue blindly - that is to say
> > before declaring an agent dead let's wait for some more time because it
> > could be stuck doing stuff. In that case I would probably make the
> > multiplier (currently 2x) configurable.
> >
> > The reason for which state report does not occur is probably that both it
> > and the resync procedure are periodic tasks. If I got it right they're
> both
> > executed as eventlet greenthreads but one at a time. Perhaps then adding
> an
> > initial delay to the full sync task might ensure the first thing an agent
> > does when it comes up is sending a heartbeat to the server?
> >
> > On the other hand, while doing the initial full resync, is the  agent
> able
> > to process updates? If not perhaps it makes sense to have it down until
> it
> > finishes synchronisation.
> Yes, it can!  The agent prioritizes updates from RPC over full resync
> activities.
> I wonder if the agent should check how long it has been since its last
> state report each time it finishes processing an update for a router.
> It normally doesn't take very long (relatively) to process an update
> to a single router.
> I still would like to know why the thread to report state is being
> starved.  Anyone have any insight on this?  I thought that with all
> the system calls, the greenthreads would yield often.  There must be
> something I don't understand about it.
> Carl
> __________________________________________________________________________
> OpenStack Development Mailing List (not for usage questions)
> Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

Kevin Benton
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20150604/f50517dd/attachment.html>

More information about the OpenStack-dev mailing list