On Mon, Feb 29, 2016, at 01:18 PM, Dan Smith wrote: > > Forgive my ignorance or for playing devil's advocate, but wouldn't the > > main difference between notifications and hooks be that notifications > > are asynchronous and hooks aren't? > > The main difference is that notifications are external and intended to > be stable (especially with the versioned notifications effort). The > hooks are internal and depend wholly on internal data structures. > > > In the case of how Rdo was using it, > > they are adding things to the injected_files list before the instance is > > created in the compute API. You couldn't do that with notifications as > > far as I know. > > Nope, definitely not, but I see that as a good thing. Injecting files > like that is likely to be very fragile and I think mostly regarded as > substantially less desirable than the alternatives, regardless of how it > happens. > > I think that Laski's point was that the most useful and least dangerous > thing that hooks can be used for is the use case that is much better > served by notifications.
Yep. My experience with them was things like updating an external cache on create/delete or calling out to a DNS provider to remove a reverse DNS entry on instance delete. Things that could easily be handled with notifications, and use cases that I think we should continue to support by improving notifications if necessary. > > So, if file injection (and any other internals-mangling that other > people may use them for) is not a reason to keep hooks, and if > notifications are the proper way to trigger on things happening, then > there's no reason to keep hooks. > > --Dan > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: > openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev