Hi Daniel,
> -----Original Message----- > From: Daniel P. Berrange [mailto:berra...@redhat.com] > Sent: 22 September 2014 12:24 > To: OpenStack Development Mailing List (not for usage questions) > Subject: Re: [openstack-dev] [Nova] - do we need .start and .end > notifications in all cases ? > > On Mon, Sep 22, 2014 at 11:03:02AM +0000, Day, Phil wrote: > > Hi Folks, > > > > I'd like to get some opinions on the use of pairs of notification > > messages for simple events. I get that for complex operations on > > an instance (create, rebuild, etc) a start and end message are useful > > to help instrument progress and how long the operations took. However > > we also use this pattern for things like aggregate creation, which is > > just a single DB operation - and it strikes me as kind of overkill and > > probably not all that useful to any external system compared to a > > single event ".create" event after the DB operation. > > A start + end pair is not solely useful for timing, but also potentially > detecting > if it completed successfully. eg if you receive an end event notification you > know it has completed. That said, if this is a use case we want to target, > then > ideally we'd have a third notification for this failure case, so consumers > don't > have to wait & timeout to detect error. > I'm just a tad worried that this sounds like its starting to use notification as a replacement for logging. If we did this for every CRUD operation on an object don't we risk flooding the notification system. _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev