On Wed, Nov 28, 2012 at 6:13 AM, Julien Danjou <julien at danjou.info> wrote: > On Tue, Nov 27 2012, Doug Hellmann wrote: > > >> I may have a better idea. > >> The problem with doing that in the pollster, is that: > >> 1. it's bad bad bad bad > >> 2. it's inefficient since you may lose values on restart > >> you won't know what the value was before > >> > > > > We will if we persist them on the compute node. > > See point 1. :-) > > > That doesn't work if different collector instances receive events from > the > > same meter on the same resource in parallel (which could happen easily if > > the queue gets backed up). > > It does if you don't try to cache locally but request the last value > From the storage backend, right? > There's a race condition, though. If you and I are processing events at the same time, we get the same "last value" from the storage but then try to update it to our current value. Doug > > -- > Julien Danjou > // Free Software hacker & freelance > // http://julien.danjou.info > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev at lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20121128/737c4a9a/attachment.html>