Comment 2 for bug 1835958

> cause a Nova sync power process to be kicked off.

I'm not sure if you're referring to the _sync_power_states periodic task:

https://github.com/openstack/nova/blob/ff0feed25d56c8ccd2298d5b5b82e636880fa986/nova/compute/manager.py#L7907

If you are, that's a mischaracterization of what happens when you create or live migrate a server. Since it's a periodic task, it runs like a cron.

Maybe you mean "claims" performed in the resource tracker, like during instance create?

https://github.com/openstack/nova/blob/ff0feed25d56c8ccd2298d5b5b82e636880fa986/nova/compute/manager.py#L2223

But again, those claims aren't (yet) made for live migration and interface attach/detach operations. So I'm a bit confused on what you're saying is taking a long time.

Regarding the _sync_power_states periodic task I've seen a few vcenter-specific patches to deal with a large number of instances when nova-compute is managing a large vcenter cluster, e.g.:

https://review.opendev.org/#/c/575034/

Also see bug 1513735.