Bug 1962344

Summary:	[SCALE] ovn-controller running up to 30 second poll intervals due to full recompute
Product:	OpenShift Container Platform	Reporter:	Tim Rozet <trozet>
Component:	Networking	Assignee:	Tim Rozet <trozet>
Networking sub component:	ovn-kubernetes	QA Contact:	Kedar Kulkarni <kkulkarn>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	medium
Priority:	high	CC:	zzhao
Version:	4.8
Target Milestone:	---
Target Release:	4.9.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	perfscale-ovn
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	1962345 (view as bug list)		Environment:
Last Closed:	2021-10-18 17:31:06 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:	1962345
Bug Blocks:

Description Tim Rozet 2021-05-19 19:06:57 UTC

Description of problem:
We see at scale of 300 nodes in a steady state cluster that ovn-controller is running anywhere between 20-30 second poll intervals. According to Dumitru the cause is a change to any SB datapath triggeringrecompute of the ct_zones and physical_flow_changes

https://github.com/ovn-org/ovn/commit/f9cab11d5fabe2ae321a3b4bad5972b61df958c0

https://github.com/ovn-org/ovn/commit/f9cab11d5fabe2ae321a3b4bad5972b61df958c0#diff-220cd89c1bf69b5cf68c6e9ea377[…]61c58aaf871f29f13d8cccd6cff1R2392

2021-05-19T18:27:02Z|03612|inc_proc_eng|DBG|node: ct_zones, recompute (triggered)
2021-05-19T18:27:02Z|03613|inc_proc_eng|DBG|controller/ovn-controller.c:1590: node: ct_zones, old_state Stale, new_state Updated
2021-05-19T18:27:02Z|03614|inc_proc_eng|DBG|node: physical_flow_changes, handle change for input ct_zones
2021-05-19T18:27:02Z|03615|inc_proc_eng|DBG|node: physical_flow_changes, can't handle change for input ct_zones, fall back to recompute
2021-05-19T18:27:02Z|03616|inc_proc_eng|DBG|node: physical_flow_changes, recompute (triggered)

Comment 1 Tim Rozet 2021-08-25 13:34:39 UTC

Also including Han's fix into this, which will greatly reduce the number of openflow flows per ovn-controller and lower the time it takes to recompute.

Comment 4 Kedar Kulkarni 2021-09-02 12:21:02 UTC

Hi,

I tested this bz on 4.9.0-0.nightly-2021-08-31-123131 cluster with 300 worker nodes, gathered 2 must gather logs, 1 as soon as cluster was ready and another after ~30 mins, I did not see the errors mentioned in the original comment in ovn-controller pod logs.


Thanks,
KK.

Comment 7 errata-xmlrpc 2021-10-18 17:31:06 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: OpenShift Container Platform 4.9.0 bug fix and security update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2021:3759