[ovs-build] Failed: ovsrobot/ovn#28 (series_122098 - 9204d7c)

Travis CI builds at travis-ci.com
Tue Jul 30 03:19:41 UTC 2019

Build Update for ovsrobot/ovn

Build: #28
Status: Failed

Duration: 33 mins and 13 secs
Commit: 9204d7c (series_122098)
Author: Han Zhou
Message: ovn-controller: Fix flow installation latency caused by recompute.

When there are in-flight flow-installations pending to ovs-vswitchd,
current incremental processing logic prioritizes new change handling.
However, in scenarios where frequent recomputes are triggered, the
later recompute would block the flow-installation for previously
computed flows because recompute usually takes long time, especially
when there are large number of flows. This results in worse latency
than the version without incremental processing in specific scale
test scenarios.

While we can simply fix the problem by prioritizing flow installation
rather than new change handling, it can cause the incremental
processing to degrade to always recompute in certain scenarios when
there are some changes triggering recomputes, followed by a lot of
continously coming changes that can be handled incrementally. Because
OVSDB change tracker cannot preserve changes across iterations, once
the recompute is triggered and resulted in a lot of pending messages
to ovs-vswitchd, and if we choose to skip the engine_run()
in the next iteration when a incrementally processible change comes,
we miss the opportunity to handle that tracked change and will have
to trigger recompute again in the next next iteration, and so on, if
such changes come continously.

This patch solves the problem by introducing engine_set_abort_recompute(),
so that we can prioritize new change handling if the change can be
incrementally processed, but if the change triggers recompute, we
abort there without spending CPU on the recompute to avoid blocking
the previous computed flow installation.

Reported-by: Daniel Alvarez Sanchez <dalvarez at redhat.com>
Reported-by: Numan Siddique <nusiddiq at redhat.com>
Reported-at: https://mail.openvswitch.org/pipermail/ovs-discuss/2019-June/048822.html
Tested-by: Numan Siddique <nusiddiq at redhat.com>
Acked-by: Numan Siddique <nusiddiq at redhat.com>
Acked-by: Mark Michelson <mmichels at redhat.com>
Signed-off-by: Han Zhou <hzhou8 at ebay.com>
Signed-off-by: 0-day Robot <robot at bytheb.org>

View the changeset: https://github.com/ovsrobot/ovn/commit/9204d7cdb877

View the full build log and details: https://travis-ci.com/ovsrobot/ovn/builds/121174699?utm_medium=notification&utm_source=email


You can unsubscribe from build emails from the ovsrobot/ovn repository going to https://travis-ci.com/account/preferences/unsubscribe?repository=9136199&utm_medium=notification&utm_source=email.
Or unsubscribe from *all* email updating your settings at https://travis-ci.com/account/preferences/unsubscribe?utm_medium=notification&utm_source=email.
Or configure specific recipients for build notifications in your .travis.yml file. See https://docs.travis-ci.com/user/notifications.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openvswitch.org/pipermail/ovs-build/attachments/20190730/8177b325/attachment.html>

More information about the build mailing list