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