live-migration will not honor destination vcpu_pin_set config
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
OpenStack Compute (nova) |
Confirmed
|
Medium
|
Unassigned |
Bug Description
Reporting this based on code inspection of the current master (commit: 9f61d1eb6427857
When we attempt to live-migrate an instance onto a host that has a different vcpu_pin_set than the one that was on the source host, we may either break the policy set by the destination host or fail (as we will not recalculate the vcpu cpuset attribute to match that of the destination host, so we may end up with an invalid range).
The first solution that jumps out is to make sure the XML is updated in https:/
However that would mean passing over the requested info from the destination host.
Changed in nova: | |
status: | New → Invalid |
Changed in nova: | |
assignee: | Diana Clarke (diana-clarke) → Nan Zhang (nanzhang) |
tags: | added: live-migration numa |
summary: |
- libvirt live-migration will not honor destination vcpu_pin_set config + live-migration will not honor destination vcpu_pin_set config |
Changed in nova: | |
assignee: | Nan Zhang (nanzhang) → nobody |
Changed in nova: | |
assignee: | nobody → Sujitha (sujitha-neti) |
Changed in nova: | |
assignee: | Sujitha (sujitha-neti) → Nikola Đipanov (ndipanov) |
status: | Confirmed → In Progress |
Changed in nova: | |
assignee: | Nikola Đipanov (ndipanov) → sahid (sahid-ferdjaoui) |
Changed in nova: | |
assignee: | sahid (sahid-ferdjaoui) → tangxing (tang-xing) |
Changed in nova: | |
assignee: | tangxing (tang-xing) → nobody |
Changed in nova: | |
assignee: | nobody → Nikola Đipanov (ndipanov) |
assignee: | Nikola Đipanov (ndipanov) → sahid (sahid-ferdjaoui) |
Changed in nova: | |
assignee: | sahid (sahid-ferdjaoui) → Stephen Finucane (stephenfinucane) |
Hi folks:
As a learning exercise[1], I tried to reproduce this bug.
Here are my notes from two test cases I tried using a multi-node devstack sandbox.
1. Source host vcpu_pin_set is larger than the destination host vcpu_pin_set:
http:// paste.openstack .org/show/ 473274/
2. Source host vcpu_pin_set is the same size as the destination host vcpu_pin_set, but with completely different values:
http:// paste.openstack .org/show/ 473286/
Conclusion: The live migration completed successfully in both cases, and it looks to me like the cpuset attribute was updated correctly to match the destination host policy, but perhaps I've misunderstood & failed to simulate a case that would trigger a migration failure or policy conflict.
Thoughts?
[1] I'm new to OpenStack.