[rabbitmq-discuss] rabbitmq message delay

[Simon MacMullen]

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https://groups.google.com/forum/#!forum/rabbitmq-users, this mailing 
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On 20/08/14 10:43, Lost wrote:
> The 1.csv delay is only 1 millisecond, but the 2.csv is need 50
> millisecond!!
> Is any possible to reduce message delay?

I'm not completely sure what you're measuring, but it sounds like you're 
talking about the end-to-end latency from producer to consumer.

To a large extent message rate and latency are in conflict, see the last 
chart (and discussion) at

http://www.rabbitmq.com/blog/2012/04/17/rabbitmq-performance-measurements-part-1/

but in brief, if you send messages as fast as you can, all the internal 
buffers in RabbitMQ fill up, and it takes longer for a message to work 
its way through them. The good news is that even at 90% of the maximum 
rate, the buffers tend to stay mostly empty and latency is much lower.

You should also be aware that RabbitMQ really doesn't make any 
*guarantees* about latency; we try to keep it low but you may see 
spikes. Low-latency messaging systems generally have designs that are 
very different from RabbitMQ (summary: if the message is late, throw it 
away!).

Cheers, Simon