[rabbitmq-discuss] durable message server restart

Wed Jan 16 22:44:35 GMT 2013

On 16/01/13 22:23, Michael Klishin wrote:
>
> 2013/1/17 Prabodh Upreti <prabodh.upreti at vce.com
> <mailto:prabodh.upreti at vce.com>>
>
>     Does this mean I need to create a durable exchange too?
>
>
> AFAIR only durable queues can be bound to durable exchanges.

Actually, that restriction was lifted some time ago.

Also, to the OP's question...

"I understand I need to create a durable queue so I can hold messages 
for consumers that connect in the future to retrieve those messages."

Durability is there for one thing and one thing only: retaining data in 
the event of broker restarts.

So, technically, to "hold messages for consumers that connect in the 
future", an ordinary queue suffices. Though if that future might entail 
broker restarts then yes, you should make the queue durable.

Another thing worth noting is that durability only affects performance 
of resource operation - i.e. creating/deleting queues, exchanges and 
bindings - *not* messaging. Though combining durability with persistence 
(see below) *does* affect performance.

> Messages need to be published as persistent (delivery mode 2).

Right. It's the conjunction of message persistence and queue durability 
that results in messages getting written to disk and survive broker 
restarts.

Regards,

Matthias.