rebus - Accepting command and raising events from a service

Question

Using Rebus as message bus over RabbitMq message broker for enabling event driven communication between micro services. Using bus.Send(command) service A sends command over a specific queue, to which service B has subscribed. we are using type based routing.

Service B during the workflow of command needs to emit events for change in status (performingA, performedA etc..). One of the handler for an event will be in service B only ( per say it will listen to a specific event and call another api).

To achieve this do I need to have 3 instances of rebus in service B? One for subscribing to command from service A and another for raising events and 3rd to handle the event?

标签： rebusrebus-rabbitmq

Answer 1

do I need to have 3 instances of rebus in service B? One for subscribing to command from service A and another for raising events and 3rd to handle the event?

No you only need one Rebus instance in service B.

One Rebus endpoint (with one input queue) is enough to:

...receive the command (you already know that )

...subscribe to an event (e.g. await bus.Subscribe<YourEvent>();)

...publish the event (e.g. await bus.Publish(new YourEvent(...);)

...receive the event (because you subscribed to it, creating a binding from a topic named after your YourEvent type to service B's input queue.