Bug 1948595

Summary:	[RFE] Add support for monitor_cond_since/update3 to Python OVS IDL library
Product:	Red Hat Enterprise Linux Fast Datapath	Reporter:	Terry Wilson <twilson>
Component:	openvswitch2.17	Assignee:	Terry Wilson <twilson>
Status:	CLOSED ERRATA	QA Contact:	Hekai Wang <hewang>
Severity:	medium	Docs Contact:
Priority:	high
Version:	FDP 22.C	CC:	apevec, ctrautma, dalvarez, dcbw, dceara, eelahi, hewang, i.maximets, jhsiao, jiji, jishi, jmelvin, lhh, majopela, ralongi, rkhan, scohen, tredaelli, yinxu
Target Milestone:	---	Keywords:	FutureFeature, Performance
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	openvswitch2.17-2.17.0-4.el8fdp	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	1957273 (view as bug list)		Environment:
Last Closed:	2022-06-30 17:59:47 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:	1503518

Description Terry Wilson 2021-04-12 14:41:06 UTC

Description of problem:

The python-ovs library does not support monitor_cond_since/update3. This means that for OSP, on large deployments where you can have 600+ connections to the SB ovsdb-server, that when you fail over ovn-dbs-bundle you break all of those connections and dump 600+ copies of the db simultaneously from the single-threaded ovsdb-server. It can take over 40 minutes for this process to actually complete and for the system to become usable.



Version-Release number of selected component (if applicable):
ovs master as of 2021-04-12 

How reproducible:

100%

Steps to Reproduce:
1. Initialize a ovsdb connection with python-ovs
2. call force_reconnect()


Actual results:

All rows from all registered tables are transferred to the client

Expected results:

Only modifications since the latest successful request are transferred to the client
Additional info:

Comment 3 Dan Williams 2021-05-05 13:53:01 UTC

Cloned this bug for the necessary changes to ovsdb. But the python bits will need updates for monitor_cond_since too, so over to python-networking-ovn for that. These two things can proceed in parallel.

Comment 4 Daniel Alvarez Sanchez 2021-05-05 14:19:22 UTC

@Terry, if i'm not mistaken the only change required here is in the OVS component and it'd be adding support for 'update3' in its Python library right?
No changes required in the OSP side, not even on ovsdb-server. Can you please confirm and select the right component?

Comment 5 Terry Wilson 2021-05-05 14:24:31 UTC

This should just be the opensvwitch component. Specifically the Python ovs library in the openvswtich component (ovs/db/idl.py). There is nothing to do on the neutron/networking-ovn side.

Comment 6 Dan Williams 2021-05-05 15:20:41 UTC

(In reply to Terry Wilson from comment #5)
> This should just be the opensvwitch component. Specifically the Python ovs
> library in the openvswtich component (ovs/db/idl.py). There is nothing to do
> on the neutron/networking-ovn side.

Fair enough, should we assign to you since you and Ihar have the most relevant commits to that code in OVS while nobody else on the OVS/OVN team does?

Comment 7 Fouad Hallal 2021-05-06 13:11:43 UTC

Dan created https://bugzilla.redhat.com/show_bug.cgi?id=1957273 to track work on ovsdb.  This BZ will be used to track Python OVS library.

Comment 8 Terry Wilson 2021-05-25 03:21:49 UTC

Sure. I have a patch started, just working on fixing tests.

Comment 9 Yaniv Kaul 2021-07-28 14:30:31 UTC

(In reply to Terry Wilson from comment #8)
> Sure. I have a patch started, just working on fixing tests.

Can you please update what's the status of the patch + tests?

Comment 10 Terry Wilson 2021-07-28 14:54:03 UTC

It was determined that I should focus on getting raft support tested and migration working, so I haven't looked at this in a while. There were quite a few test failures, mostly it looked like it was due to the graceful fallback from monitor_cond_since -> monitor_cond -> monitor. I'll see if I can at least get a patch up on a github fork to give someone else a head start if this needs to progress without me.

Comment 12 Ilya Maximets 2022-04-01 11:09:18 UTC

Upstream patch:
  https://patchwork.ozlabs.org/project/openvswitch/patch/20211201175120.3229612-1-twilson@redhat.com/

Comment 13 Terry Wilson 2022-04-27 14:37:48 UTC

Other patches related to the monitor-cond-since support patch:

4e3966e64 python: Politely handle misuse of table.condition
d29491eeb python: idl: Set cond_changed to true if condition change requested.
e3de0bd82 python: idl: Set cond_changed to false if last id is zero.
6de8868d1 reconnect: Fix broken inactivity probe if there is no other
reason to wake up.
5202710a7 python: idl: Clear last_id on reconnect if condition changes
in-flight.
718dc8fca python: idl: Resend requested but not acked conditions when
reconnecting.
46d44cf3b python: idl: Add monitor_cond_since support.

all appear to be in branch-2.17.

Comment 20 errata-xmlrpc 2022-06-30 17:59:47 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 (openvswitch2.17 bug fix and enhancement 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/RHBA-2022:5445