[nova] Stein regressions

Matt Riedemann mriedemos at gmail.com
Wed Apr 17 02:30:55 UTC 2019

Hey cool cats,

I know we just released Stein last week so what better time to write an 
email about a bunch of Stein regressions?!

I wanted to dump this in the list so (a) I don't lose track of them all 
and (b) other people are aware and get involved.

In no particular order:

1. https://bugs.launchpad.net/nova/+bug/1822801

There is a patch being worked: https://review.openstack.org/#/c/649345/

The workaround for this would be to disable the 
_heal_instance_info_cache periodic in nova-compute services that manage 
baremetal nodes by setting the heal_instance_info_cache_interval value to 0.

2. https://bugs.launchpad.net/nova/+bug/1824435

We have a re-create scenario for this in devstack (noted in the bug 
report). I've been unable to recreate in a functional test, possibly 
because of how sqlite deals with NULL values in unique constraints 
differently from mysql. I would have thought this regression test [1] 
would have hit it but it didn't.

There are some options for fixing this, some more hacky than others, e.g.:


Need some input from others on fixing that bug in maybe a less hacky way.

3. https://bugs.launchpad.net/nova/+bug/1825034

I found this when writing [1] to try and recreate the previous bug 
1824435. I have a series up for this starting with a recreate patch [1].
The fix on top is one of a few options I detailed in the bug report. 
It's not pretty but it works.

The workaround for this would be to archive deleted records but you'd 
have to do that after each run of the online data migration which is not 

4. https://bugs.launchpad.net/nova/+bug/1825020

I just triaged this a couple of hours ago. I plan on writing a 
functional regression recreate test since the recreate scenario seems 
pretty easy - try to resize a volume-backed server where the new flavor 
has a smaller disk than the old flavor. The fix should also be 
relatively straight-forward.


Once we get fixes landed and backported to stable/stein for these bugs 
we should do a patch release ASAP.

[1] https://review.openstack.org/#/c/653098/




More information about the openstack-discuss mailing list