[rabbitmq-discuss] Pub/Sub Guaranteed Delivery

[Alexis Richardson]

On Tue, Sep 25, 2012 at 1:10 PM, Francisco Aguiar Zanfranceschi
<zanfranceschi at gmail.com> wrote:
> I'd like to say that's probably easier if I ask what's the best way to
> guarantee all subscribers receive all messages even when they go offline
> using RabbitMQ. I imagine all of us had that challenge or will have it
> sooner or later. I'm sorry to kind of bump this discussion.

You want to make sure that each consumer (subscribed client) can have
its messages held in a queue, while it is offline, so that it can get
the messages when it reconnects.  This is achievable using the pattern
I linked to in my previous post on this thread.

Then, you need to make sure that when it does connect, the messages
get to the consumer and only after you know that happened, is the
message deleted from the queue.  This is achievable by using
acknowledgement.

Does this answer your question?

It is also important to understand the failure scenarios clearly,
whenever words like "guarantee" are bandied about ;-)