Mistral tries to connect to RabbitMQ even when starting with option "--server all"

[Renat Akhmerov]

When I start Mistral as

mistral-server --server all --config-file etc/mistral-poc-demo.conf

and open RabbitMQ dashboard (usually http://localhost:15672/#/connections) I see active connections created on behalf of py-amqp. This is a bug because when we start all three components (engine, api, executor) the process must not use RabbitMQ at all but rather use an in-memory transport.

[Winson Chan (winson-c-chan)]

The conf file needs to set rpc_backend to fake. The default rpc_backend is set to rabbit @ https://github.com/openstack/oslo.messaging/blob/master/oslo/messaging/transport.py#L43. The launch script doesn't change the rpc_backend automatically to fake when all servers are launched together because I think that should be a choice that the operator makes. Conceptually, one can run all three processes together and still uses other transports (i.e. rabbitMQ) for their non-functional requirements.