On Sun, Feb 4, 2024 at 5:46 AM Ilya Maximets <i.maxim...@ovn.org> wrote: > > >>> > >>> > 35 files changed, 9681 insertions(+), 4645 deletions(-) > >>> > >>> I had another look at this series and acked the remaining patches. I > >>> just had some minor comments that can be easily fixed when applying the > >>> patches to the main branch. > >>> > >>> Thanks for all the work on this! It was a very large change but it > >>> improves northd performance significantly. I just hope we don't > >>> introduce too many bugs. Hopefully the time we have until release will > >>> allow us to further test this change on the 24.03 branch. > >>> > >>> Regards, > >>> Dumitru > >> > >> > >> > >> Thanks a lot Dumitru and Han for the reviews and patience. > >> > >> I addressed the comments and applied the patches to main and also to > > branch-24.03. > >> > >> @Han - I know you wanted to take another look in to v6. I didn't want to > > delay further as branch-24.03 was created. I'm more than happy to submit > > follow up patches if you have any comments to address. Please let me know. > >> > > > > Hi Numan, > > > > I was writing the reply and saw your email just now. Thanks a lot for > > taking a huge effort to achieve the great optimization. I only left one > > comment on the implicit dependency left for the en_lrnat -> en_lflow. Feel > > free to address it with a followup and no need to block the branching. And > > take my Ack for the series with that addressed. > > > > Acked-by: Han Zhou <hzhou at ovn.org> > > > Hi, Numan, Dumitru and Han. > > I see a huge negative performance impact, most likely from this set, on > ovn-heater's cluster-density tests. The memory consumption on northd > jumped about 4x and it constantly recomputes due to failures of port_group > handler: > > 2024-02-03T11:09:12.441Z|01680|inc_proc_eng|INFO|node: lflow, recompute (failed handler for input port_group) took 9762ms > 2024-02-03T11:09:12.444Z|01681|timeval|WARN|Unreasonably long 9898ms poll interval (5969ms user, 1786ms system) > ... > 2024-02-03T11:09:23.770Z|01690|inc_proc_eng|INFO|node: lflow, recompute (failed handler for input port_group) took 9014ms > 2024-02-03T11:09:23.773Z|01691|timeval|WARN|Unreasonably long 9118ms poll interval (5376ms user, 1515ms system) > ... > 2024-02-03T11:09:36.692Z|01699|inc_proc_eng|INFO|node: lflow, recompute (failed handler for input port_group) took 10695ms > 2024-02-03T11:09:36.696Z|01700|timeval|WARN|Unreasonably long 10890ms poll interval (6085ms user, 2745ms system) > ... > 2024-02-03T11:09:49.133Z|01708|inc_proc_eng|INFO|node: lflow, recompute (failed handler for input port_group) took 9985ms > 2024-02-03T11:09:49.137Z|01709|timeval|WARN|Unreasonably long 10108ms poll interval (5521ms user, 2440ms system) > > That increases 95%% ovn-installed latency in 500node cluster-density from > 3.6 seconds last week to 21.5 seconds this week. > > I think, this should be a release blocker. > > Memory usage is also very concerning. Unfortunately it is not tied to the > cluster-density test. The same 4-5x RSS jump is also seen in other test > like density-heavy. Last week RSS of ovn-northd in cluster-density 500 node > was between 1.5 and 2.5 GB, this week we have a range between 5.5 and 8.5 GB. > > I would consider this as a release blocker as well. > > > I don't have direct evidence that this particular series is a culprit, but > it looks like the most likely candidate. I can dig more into investigation > on Monday. > > Best regards, Ilya Maximets.
Thanks Ilya for reporting this. 95% latency and 4x RSS increase is a little surprising to me. I did test this series with my scale test scripts for recompute performance regression. It was 10+% increase in latency. I even digged a little into it, and noticed ~5% increase caused by the hmap used to maintain the lflows in each lflow_ref. This was discussed in the code review for an earlier version (v2/v3). Overall it looked not very bad, if we now handle most common scenarios incrementally, and it is reasonable to have some cost for maintaining the references/index for incremental processing. I wonder if my test scenario was too simple (didn't have LBs included) to find the problems, so today I did another test by including a LB group with 1k LBs applied to 100 node-LS & GR, and another 1K LBs per node-LS & GR (101K LBs in total), and I did see more performance penalty but still within ~20%. While for memory I didn't notice a significant increase (<10%). I believe I am missing some specific scenario that had the big impact in the ovn-heater's tests. Please share if you dig out more clues . Thanks, Han _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
