Rajith - I suppose I forgot to add that detail - there are two processes running as part of each run - a sender and a receiver; the receiver only exits (and thus the test run only finishes) once the receiver has consumed all sent messages and deleted the queue.
I see the same slowdown if the sender and reciver are running simultaneously or if the receiver only starts after the sender has finished sending all messages. Thus, between two test runs, there are no outstanding messages in the broker. Furthermore, I can sleep for minutes (or more) between test runs (after running an 8k test), and still observe the same slowdown. In either case, the sender will finish first - the slowdown seems to only affect the receiver. The messages per second processed by the sender is unchanged; that metric for the sender is (more? less? whichever is worse) than halved. Sorry - I should've stated all this in the first place, but thanks! -Rob On Fri, 2009-01-23 at 16:57 -0500, Rajith Attapattu wrote: > Hello Rob, > > Between two tests do you wait until the queue is completely drained? > That is when you run the large message test, do you wait untill all those > messages are consumed before you start the small message test? > > What is happening is that during the large messages test, the consumer will > take more time to drain the queues and there will be a backlog of messages > in the broker. When that happens the memory consumption will grow and will > likely slow the broker down. > > It is best to build your tests with feedback, i.e not start the small > message test until the large message test is complete. > Otherwise your small message test results will be skewed by the load induced > by the large message test. > And an even better way to do it is to have more a fine grained feedback > loop. That is you send in batches of x messages and you wait for > confirmation from the consumer side that it has received all x. Once you > receive that you can send the next batch of x messages. > Hope this helps. > > Regards, --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:[email protected]
