This bug was fixed in the package neutron - 2:12.0.1-0ubuntu1.1 --------------- neutron (2:12.0.1-0ubuntu1.1) bionic; urgency=medium
* d/p/remove-race-and-simplify-conntrack-state-management.patch: Cherry-picked from upstream stable/queens branch to prevent ovs-agent from eating up CPU (LP: #1750777). * d/gbp.conf: Create stable/queens branch. -- Corey Bryant <corey.bry...@canonical.com> Wed, 02 May 2018 15:00:58 -0400 ** Changed in: neutron (Ubuntu Bionic) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1750777 Title: openvswitch agent eating CPU, time spent in ip_conntrack.py Status in Ubuntu Cloud Archive: Fix Committed Status in Ubuntu Cloud Archive queens series: Fix Committed Status in neutron: Fix Released Status in neutron package in Ubuntu: Fix Released Status in neutron source package in Bionic: Fix Released Status in neutron source package in Cosmic: Fix Released Bug description: We just ran into a case where the openvswitch agent (local dev destack, current master branch) eats 100% of CPU time. Pyflame profiling show the time being largely spent in neutron.agent.linux.ip_conntrack, line 95. https://github.com/openstack/neutron/blob/master/neutron/agent/linux/ip_conntrack.py#L95 The code around this line is: while True: pool.spawn_n(self._process_queue) The documentation of eventlet.spawn_n says: "The same as spawn(), but it’s not possible to know how the function terminated (i.e. no return value or exceptions). This makes execution faster. See spawn_n for more details." I suspect that GreenPool.spawn_n may behave similarly. It seems plausible that spawn_n is returning very quickly because of some error, and then all time is quickly spent in a short circuited while loop. SRU details for Ubuntu: ----------------------- [Impact] We're cherry-picking a single bug-fix patch here from the upstream stable/queens branch as there is not currently an upstream stable point release available that includes this fix. We'd like to make sure all of our supported customers have access to this fix as there is a significant performance hit without it. [Test Case] The following SRU process was followed: https://wiki.ubuntu.com/OpenStackUpdates In order to avoid regression of existing consumers, the OpenStack team will run their continuous integration test against the packages that are in -proposed. A successful run of all available tests will be required before the proposed packages can be let into -updates. The OpenStack team will be in charge of attaching the output summary of the executed tests. The OpenStack team members will not mark ‘verification-done’ until this has happened. [Regression Potential] In order to mitigate the regression potential, the results of the aforementioned tests are attached to this bug. To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-archive/+bug/1750777/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp