On Tue, Nov 12, 2013 at 03:07:19PM -0500, Andrew Laski <andrew.la...@rackspace.com> wrote:
> On 11/11/13 at 05:27pm, Jiang, Yunhong wrote: > >Resend after the HK summit, hope someone can give me hint on it. > > > >Thanks > >--jyh > > > >>-----Original Message----- > >>From: Jiang, Yunhong [mailto:yunhong.ji...@intel.com] > >>Sent: Thursday, November 07, 2013 5:39 PM > >>To: openstack-dev@lists.openstack.org > >>Subject: [openstack-dev] [nova][api] Is this a potential issue > >> > >>Hi, all > >> I'm a bit confused of followed code in ./compute/api.py, which will be > >>invoked by api/openstack/compute/servers.py, _action_revert_resize(). > >> From the code seems there is a small windows between get the > >>migration object and update migration.status. If another API request > >>comes at this small window, it means two utility will try to revert resize > >>at > >>same time. Is this a potential issue? > >> Currently implementation already roll back the reservation if > >>something wrong, but not sure if we should update state to "reverting" as > >>a transaction in get_by_instance_and_status()? > > The migration shouldn't end up being set to 'reverting' twice > because of the expected_task_state set and check in > instance.save(expected_task_state=None). The quota reservation > could happen twice, so a rollback in the case of a failure in > instance.save could be good. nova.objects.instance.Intance.save() seems like that expected_task_state=None means don't care of task state instead of no-task going-on. Am I missing anything? thanks, > > >> > >>--jyh > >> > >> def revert_resize(self, context, instance): > >> """Reverts a resize, deleting the 'new' instance in the process.""" > >> elevated = context.elevated() > >> migration = > >>migration_obj.Migration.get_by_instance_and_status( > >> elevated, instance.uuid, 'finished') > >> >>>>>>>>>>>>>>>>>>>>>>Here we get the migration object > >> > >> # reverse quota reservation for increased resource usage > >> deltas = self._reverse_upsize_quota_delta(context, migration) > >> reservations = self._reserve_quota_delta(context, deltas) > >> > >> instance.task_state = task_states.RESIZE_REVERTING > >> instance.save(expected_task_state=None) > >> > >> migration.status = 'reverting' > >> >>>>>>>>>>>>>>Here > >>we update the status. > >> migration.save() > >> > >>_______________________________________________ > >>OpenStack-dev mailing list > >>OpenStack-dev@lists.openstack.org > >>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > >_______________________________________________ > >OpenStack-dev mailing list > >OpenStack-dev@lists.openstack.org > >http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Isaku Yamahata <isaku.yamah...@gmail.com> _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
