If I have prefetch set to 1 and I retrieve a message, is another one dispatched before it is ack'd? I'm trying to scale the number of consumers. My benchmark test pre-produces 50 messages for each consumer (all in one queue). Then sets N consumers active and I measure the time it takes to pull the message of the queue.
In my benchmarking I've found a very nice MEAN time to retrieve a message at 2ms, regardless of the number of consumers. However, the deviation is very bad. My hypothesis is that some consumers are getting stuck not able to pull messages off the queue because each consumer can actually be dispatched 2 messages. Also the faster the consumer the worse the deviation.
