oslo.messaging transport does not work with multiple transport hosts in the same(HA) RMQ cluster specified as transport://user:pass@host1:port[,hostN:portN]/virtual_host

[Rohit Jaiswal]

When specifying messaging_urls = rabbit://guest:password@192.168.19.130:5672,192.168.19.131:5674

oslo.messaging considers the first host as Transport and neglects others.

It only seems to work when this is done:

messaging_urls = rabbit://guest:password@192.168.19.130:5672
messaging_urls = rabbit://guest:password@192.168.19.131:5674

When specifying multiple transport hosts as belonging to same cluster in HA (without LB), the configuration is expected to be of the form: transport://user:pass@host1:port[,hostN:portN]/virtual_host

However, we tested with messaging_urls = rabbit://guest:password@192.168.19.130:5672,192.168.19.131:5674

and found that oslo.messaging allowed connects only to 192.168.19.130:5672.

[Rohit Jaiswal (rohit-jaiswal-3)]

On further analysis, looks like oslo_messaging: transport.py is parsing the url correctly and identifying the multiple hosts, ports.

[Davanum Srinivas (DIMS) (dims-v)]

Looks like you are talking about ceilometer's config option:
https://github.com/openstack/ceilometer/blob/master/ceilometer/notification.py#L56

[Rohit Jaiswal (rohit-jaiswal-3)]

Invalidated it since the behavior with multi-host configuration on a single line is to establish a connection to one host at a time (usually the first) and then failover to the second if the first fails..

[Mike Dorman (mdorman-m)]

Actually this appears to just be a doc bug. The notifications/messaging_urls help string indicates this format:

transport://user:pass@host1:port[,hostN:portN]/virtual_host

When in fact, what's needed is the credentials provided for each host in the list, like this:

transport://user:pass@host1:port[,user:pass@hostN:portN]/virtual_host

[Mike Dorman (mdorman-m)]

Fixed in https://review.openstack.org/#/c/313266/