[nova] [deployment] [HA] consoleauth cannot be run in HA configuration without external memcache

[Timur Nurlygayanov]

We have the following bug in Nova upstream:
https://bugs.launchpad.net/nova/+bug/1243306

the root of the issue in some bugs in Nova services, which require to use external memcache service to store consoleauth credentials & sessions. We already have external memcache service in MOS (we use it for Keystone) and we need to configure Nova to use the same external memcache service to store the information - it will help to avoid the original issue.

It is customer-found issue and we need to prepare some fix or workaround for the issue in MOS 7.0

[Timur Nurlygayanov (tnurlygayanov)]

The original issue has "wishlist" priority, just because it is possible to solve the issue with external memcache service.
For MOs this issue has High priority because we need to configure external memcache service in MOS to avoid the original issue.

[Roman Podoliaka (rpodolyaka)]

As of 7.0 we already deploy and configure an external memcache server:

root@node-145:~# grep memcache /etc/nova/nova.conf
#memcached_servers=<None>
memcached_servers=192.168.0.21:11211,192.168.0.44:11211,192.168.0.45:11211

This must be an OK workaround for the customer.

[Roman Podoliaka (rpodolyaka)]

At this point we don't want to do any structural changes to Nova to propagate the tokens between consoleauth processes for no good reason, an external memcache server must be good enough.

[Roman Podoliaka (rpodolyaka)]

And this is not going to be fixed in 8.0 either, as it's too late to propose such changes to Liberty. The best we can do is Mitaka.