Add devref documentation for live-migration

[Mathieu Rohon]

Currently, no devref exists about interactions between nova and neutron when nova performs a live-migration.
This would be useful to better understand how neutron can detect that a live-migration is ongoing, and perform dedicated treatments if needed.

This could be a building block to fix bugs such as :

https://bugs.launchpad.net/neutron/+bug/1456073
https://bugs.launchpad.net/neutron/+bug/1414559
https://bugs.launchpad.net/neutron/+bug/1483601
https://bugs.launchpad.net/neutron/+bug/1443421

[Manjeet Singh Bhatia (manjeet-s-bhatia)]

I also feels this should be done so I +1 this bug

[Mathieu Rohon (mathieu-rohon)]

I think it would also be the opportunity to add live-migration tests in neutron, that emulate scenario described in the devref.

I think about using fullstack for this kind of tests.

Thoughs?

[Assaf Muller (amuller)]

Since fullstack doesn't use Nova, we'd have to simulate whatever Nova does during a migration. I don't expect Nova to change its interaction with Neutron during live migration, so as long as we can simulate that to a sufficient degree, it should be valuable.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/274097

[OpenStack Infra (hudson-openstack)]

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/274097
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.

[Armando Migliaccio (armando-migliaccio)]

Anyone willing to take over?

[Mathieu Rohon (mathieu-rohon)]

Hi armando,

I was waiting for oleg's patches to land [1], and I need to investigate failure cases.

If anyone wants to take this patch over, please do.

Otherwise I'll revisit it ASAP.

[1] https://review.openstack.org/#/q/topic:bug/1414559

[OpenStack Infra (hudson-openstack)]

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/274097
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.

[Armando Migliaccio (armando-migliaccio)]

It would be nice to resume this work.

[Launchpad Janitor (janitor)]

[Expired for neutron because there has been no activity for 60 days.]

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/274097
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=b79f8ef8a80c0ac91b78643949a8349ca170c3ec
Submitter: Jenkins
Branch: master

commit b79f8ef8a80c0ac91b78643949a8349ca170c3ec
Author: Mathieu Rohon <email address hidden>
Date: Thu Jan 21 17:40:21 2016 +0000

    Devref to explain nova-neutron interactions during live-migration

    Closes-bug: #1531511
    Co-Authored-By: Andreas Scheuring <email address hidden>
    Change-Id: I3532c1766672f78d67de7995e04a6749f75d5c7a

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 11.0.0.0b2 development milestone.