Hi,

I am not sure about the actual default value for notification_format (I can recall that there was some debate recently in nova community),

but the solution should be to select unversioned, as most consumers of nova notifications use the legacy unversioned notifications, so

if the config is both, the new versioned notifications can cause trouble on message bus as nobody fetch them.

Lajos

Pawel Konczalski <pawel.konczalski@everyware.ch> ezt írta (időpont: 2019. júl. 24., Sze, 18:42):

Hello everybody,

after some investigation in the RabbitMQ problems we found some
duplicated messages and timeouts in logs. Restarting the whole RabbitMQ
cluster (stop all rabbitmq containers and start one by one) solved the
problems for now.

The main cause for this issue seams to by the nova notifications
configuration with was deployed by kolla-ansible. If searchlight is not
installed the 'notifications/notification_format' should be
'unversioned'. Default is 'both' so nova will send a notification to the
queue versioned_notifications with has no consumer. In our case the
queue got huge amount of messages with made the rabbitmq cluster more
and more unstable, see: https://bugzilla.redhat.com/show_bug.cgi?id=1592528

Following settings in nova.conf may solve this issue but we didn`t
tested this yet:
[notification]
notification_format = unversioned

BR

Pawel