[rabbitmq-discuss] Simple benchmark and results

Sylvain Hellegouarch sh at defuze.org
Wed Oct 21 19:20:24 BST 2009

David Glaubman a écrit :
> Philippe Kirsanov wrote:
>>> What exactly "noAck" parameter in basicConsume mean? Is it auto-ack
>>> on message or something else? API guide sais it is "handshake ack".
> I think it means auto-ack -- when I set it true in BasicConsume 
> and remove the call to BasicAck my receive performance more than tripled.
> Here’s a quote on noAck: 
> (http://www.trapexit.org/forum/viewtopic.php?p=48116)
>     AMQP says that a broker shouldn't forget about a msg until it's been 
>     ack'd. Now this can either happen by an explicit ack coming from the 
>     consumer, or from an implicit ack, by setting noAck to true when 
>     subscribing to the queue. Yes, the unfortunate naming of "noAck" is, um, 
>     unfortunate. Internally, we tend to invert this and then call it 
>     AckRequired.
> Hope this helps.

I assume this means that if the consumer fails at processing correctly 
the message it won't see it again right, whereas with an ack by the 
consumer, one can ensure consistency if the processing fails before the 
ack call.

- Sylvain

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