listen to all necessary notifications for updating Compute CDM¶
https://blueprints.launchpad.net/watcher/+spec/listen-all-necessary-notifications
Problem description¶
In Watcher, it firstly builds compute CDM by collecting nova compute resource, later updates the compute CDM by listening to nova notifications. It has listened to following nova events,
service.update
instance.update
instance.delete.end
compute.instance.update
compute.instance.create.end
compute.instance.delete.end
compute.instance.live_migration.post.dest.end
In one cloud env, there would be many solutions, which would make the compute resource strongly relocated, such as ‘auto-scaling’ solution and ‘compute-ha’ solution. If Watcher doesn’t listen to all the notifications which represent that nova compute resource changes, the compute CDM will become stale easily and watcher would not provide efficient solution.
Use Cases¶
As an OpenStack administrator, I want Watcher still to work steady when other projects make the compute resources changed.
Proposed change¶
Following events also represent that nova compute resource changes. Watcher needs to listen to the following notifications and update the compute model.
compute.instance.rebuild.end
compute.instance.resize.confirm.end
Notification ‘compute.instance.rebuild.end’ represents the ‘evacuate’ action of one instance is finished, while notification ‘compute.instance.resize.confirm.end’ represents the ‘resize’ action of one instance is finished and confirmed by the user. Once Watcher listens to such notifications, it needs to update the instances mapping in the compute model.
Alternatives¶
None
Data model impact¶
None
REST API impact¶
None
Security impact¶
None
Notifications impact¶
None
Other end user impact¶
None
Performance Impact¶
None
Other deployer impact¶
None
Developer impact¶
None
Implementation¶
Assignee(s)¶
Primary assignee: sue
Work Items¶
listen to ‘compute.instance.rebuild.end’ event
listen to ‘compute.instance.resize.confirm.end’ event
Dependencies¶
None
Testing¶
Unit test
Documentation Impact¶
None
References¶
None
History¶
None
