MDB not picking up messages immediately after done processing previous message

[xin.wu]

Hello,

I've spent days on a seemingly simple Hornetq/MDB problem, but can't get it work properly, hopefully someone here can give me a clue or two. Thanks in advance!

Here is my problem: a MDB is configured to listen on a queue in a in-vm HorneMtq, so when messages come in, the MDB processes them dutifully. when there are a few messages(say 30) coming in at the same time, by default, only 15 of them can be processed, and rest of them will have to wait until some instances of MDB done processing previous messages. But the problem is when MDB instances complete processing messages, they don't pick up messages in the queue immediately, but with some delay.

So my question is how to make the MDB run at full capacity so that whenever an instance of MDB completes processing a message, immediately it picks up another message in the queue? I tried several configuration parameters such as client side buffering, thread pool size, keep-alive time, instance acquisition time out, but none of them worked. Any ideas? Thanks!

William

[jbertram]

In general, this is not the behavior I would expect.  I would expect the MDB to pick up the next message immediately.  It's possible that messages could be sitting in the consumers' buffers.  You indicated that you modified the client-side buffering configuration; did you disable client-side buffering completely (i.e. consumerWindowSize = 0)?

I recommend you get a series of thread dumps to see what might be happening during the interim time between when the MDB finishes processing one message and picks up the next one. 

[xin.wu]

Hi Justin,

Thanks for the quick reply. I'd tried disabling client-side buffering before you suggested it, but on a wrong connection factory. Once it's done on the correct connection factory, it works perfectly. Thanks again!

[jbertram]

I'm glad it's working for you.

One last note...To avoid confusion you can simply set the "consumerWindowSize" activation configuration property directly on the MDB itself rather than on the connection factory.