[rabbitmq-discuss] Is there a use case for a queue with auto_delete=True and durable=True?

Fri Jan 23 17:33:26 GMT 2009

Hi Barry,

Just for the record, I think I agree that the defaults should be  
towards minimizing leftovers on the server unless specifically  
desired.  So I think that setting auto_delete = true and durable =  
false by default makes sense.  The sometimes unfortunate bit is that  
to get what I was expect for "durable" queues, I need to set both flag  
in the opposite.

My only question here I guess is a curiosity one - is there a use case  
for having an auto-deleting, but durable queue?  I did look through  
the spec again but didn't find something along these lines.

Sorry Ben, I agree I should have sent this directly to the list.  ;)

Thanks all,
Brian

On Jan 23, 2009, at 7:19 AM, Barry Pederson wrote:

> Ben Hood wrote:
>> Brian Sullivan wrote:
>>> Is there a use case for this combination of settings?  I have seen  
>>> some
>>> posts that have been confused by not having queues remain when
>>> durable=true if people forget to set auto-delete=false, so it  
>>> seems odd to
>>> have the defaults set the way they are (at least as they appear to  
>>> be in
>>> the python lib)
>> I would consider it to be odd, but I'm not a lawyer.
>> Though the exact behavior of this scenario is IMHO not clearly  
>> defined
>> in the spec, I think that most implementations would take a common
>> sense approach.
>> From the perspective of py-amqplib, I would say that it's over to
>> Barry to make a call on this.
>
> Brian:
>
> IIRC as far as the py-amqplib defaults go...my thought was that if  
> you're going to do something that makes a persistent change the  
> server, such has having a queue that's durable, then I thought you  
> should explicitly say so.  That way if you're just dabbling around  
> or don't exactly know what you're doing, there's no permanent harm  
> done.
>
> Even if a case could be made that the defaults are not ideal, it's  
> probably too late to change it now.  I supposed it could be  
> addressed in documentation.
>
> I agree that having the separate durable and auto_delete flags can  
> be confusing, but that comes from the spec, and is just passed  
> through by the client library - the broker is where the flags have  
> an impact.
>
> 	Barry
>