[rabbitmq-discuss] Typical physical setup questions

Tue Aug 7 10:33:50 BST 2012

Hi John,

On 06/08/12 23:01, John Kemp wrote:
> Server A - ecommerce web server
> Server B - app server running order processing (reads from queue) - also
> assum RabbitMQ broker
> 
> * Should both Server A and Server B be running local instances of RabbitMQ?

That is not be required for simple messaging. A and B can communicate
via a single logical message broker (or "Transport").

> * Can I set up both servers to persist to the same db instance?

There's only one message broker, so no need for multiple persistent
message stores. The broker has a persistent store for messages.

> * If only Server B needs an instance, what happens if Server B goes
> down? Are all messages lost on Server A?

If A or B are unavailable or disconnected then the message flow between
them is interrupted. But because the broker forwards messages on their
behalf, it provides continuity. Messages that are not completely
processed can be redelivered.

> * How do you handle message loss?

The risk of message loss can be minimised. Publishers can obtain
confirmation that messages were received by the broker and subscribers
can acknowledge messages when processing completed successfully. And
RabbitMQ provides high-availability features to protect against broker
failure.

I'm not sure if all of these features are available via Mass Transit.
You should consult the Mass Transit documentation for specific on how to
set that up.

-Emile