And you can use the nova option "live_migration_inbound_addr" [1] to avoid the impact of live migration at all, but that require additional network plane.
[1]: https://github.com/openstack/nova/blob/master/nova/conf/libvirt.py#L243-L258 [2]: https://blueprints.launchpad.net/nova/+spec/split-network-plane-for-live-migration 2016-12-30 20:56 GMT+08:00 Koniszewski, Pawel <[email protected]>: > Matt, > > > > This was a bandwidth issue. Nova kept being connected to the broker, but > it started to timeout on RPC messages, e.g., we lost some RPC messages > triggering post live migration steps which are there to update nova DB to > reflect new host of an instance. > > > > The good workaround for this issue is to slightly limit bandwidth used for > live migrations through nova.conf [1], live_migration_bandwidth config > option in [libvirt] section. By default it is set to 0, so, basically, it > is unlimited. Also please be aware that we changed default live migration > configuration in OpenStack Newton and tunneling is now off by default > (live_migration_tunnelled in [libvirt] section is set to False) due to huge > performance impact. > > > > [1] http://docs.openstack.org/newton/config-reference/ > compute/config-options.html > > > > Kind Regards, > > Pawel Koniszewski > > > > *From:* [email protected] [mailto:[email protected]] *On Behalf Of *Matt > Fischer > *Sent:* Friday, December 30, 2016 5:31 AM > *To:* Koniszewski, Pawel <[email protected]> > *Cc:* [email protected] > *Subject:* Re: [Openstack-operators] [nova] Live migration performance > tests on 100 compute nodes > > > > On Wed, Dec 28, 2016 at 6:11 AM, Koniszewski, Pawel < > [email protected]> wrote: > > Hello everyone, > > We made a research to see how live migration performance varies between > different configurations, especially we aimed to test tunneled vs > non-tunneled live migrations. To test live migration we simulated a case of > 0-day patching of 100 compute nodes (including reboot) with workloads that > are close to the real world workloads. All the results were published [1] > along with environment configuration and how we built test framework. Hope > you find this useful. > > [1] https://01.org/openstack/blogs/pkoniszewski/2016/ossc- > zero-day-patching > > Kind Regards, > Pawel Koniszewski > > > > Thanks for the write-up. I'm curious about your RabbitMQ connection > failures. Was it nova-compute failing to connect? Was it a bandwidth or > heartbeat issue? > > _______________________________________________ > OpenStack-operators mailing list > [email protected] > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators > >
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