Bug 2057568

Summary:	[RFE][ovn] Investigate feasibility of supporting upgrading ovn-central before ovn-host
Product:	Red Hat Enterprise Linux Fast Datapath	Reporter:	Daniel Alvarez Sanchez <dalvarez>
Component:	ovn-2021	Assignee:	Mark Michelson <mmichels>
Status:	CLOSED WONTFIX	QA Contact:	Jianlin Shi <jishi>
Severity:	urgent	Docs Contact:
Priority:	high
Version:	FDP 22.G	CC:	bcafarel, ctrautma, dcbw, jiji, jpretori, michal.skrivanek, mmichels, smooney
Target Milestone:	---	Keywords:	FutureFeature
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-07-28 17:26:53 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2058333

Comment 4 Dan Williams 2022-03-01 18:47:14 UTC

I cannot see how this bug is Urgent, given that OVN has only supported node-before-controller since the beginning. That's not a regression.

If there is some functionality that broke unexpectedly within the supported model above, then *that* could potentially be an urgent fix.

Comment 5 Mark Michelson 2022-03-04 14:47:53 UTC

Updating the summary to indicate that this is an investigative task rather than an implementation one. The OVN team will do investigation and come up with more concrete smaller subtasks to perform to reach this goal, assuming that the investigation finds that this sort of upgrade is feasible.

Comment 6 Michal Skrivanek 2022-05-31 08:36:02 UTC

(In reply to Dan Williams from comment #4)
> I cannot see how this bug is Urgent, given that OVN has only supported
> node-before-controller since the beginning. That's not a regression.

Then this was very poorly communicated, for instance RHV team for years of support of OVN never defined any upgrade order, the order is flexible and RHV is routinely upgraded with controller first.

Comment 7 Dan Williams 2022-05-31 15:01:00 UTC

(In reply to Michal Skrivanek from comment #6)
> (In reply to Dan Williams from comment #4)
> > I cannot see how this bug is Urgent, given that OVN has only supported
> > node-before-controller since the beginning. That's not a regression.
> 
> Then this was very poorly communicated, for instance RHV team for years of
> support of OVN never defined any upgrade order, the order is flexible and
> RHV is routinely upgraded with controller first.

Likely could be better communicated, yes.

Though the OVN upgrade documentation here:

https://docs.ovn.org/en/latest/intro/install/ovn-upgrades.html
(sourced from https://github.com/ovn-org/ovn/blob/main/Documentation/intro/install/ovn-upgrades.rst)

hasn't changed in ~6 years and it's pretty clear about upgrading controllers first.

Comment 8 Mark Michelson 2023-07-28 17:26:53 UTC

I'm closing this issue. We have taken measures in OVN to make central-first upgrades less hostile, though it is still not the officially-supported upgrade method. OpenStack has also worked around their previous methods of updating the central components before the ovn-controllers.