It's unclear to me what the root cause of this could be. The java.util.concurrent.ExecutorService used here is created using java.util.concurrent.Executors.newCachedThreadPool(java.util.concurrent.ThreadFactory) which should create as many new threads as are necessary. In other words, I don't see why a task would ever be rejected by it.
Can you provide any details about the use-case here or the series of events which led to this error?
Also, why are you using such an old version (i.e. 2.2.14.Final)? Are you able to reproduce this error on a current release?
The use case is that we are using a script to exercise a component that generates hundreds of messages entering the queue. And, via jconsole, we can see that the messages are received by the consumers and deleted promptly from the queue.
The rate is slow - less than 10 messages per second.
At a certain point (within 5 minutes) HQ crashes with the error.
We are using such an old version of HQ due to customer requirements.
Thanks for your assistance!
Based on your description it appears you have reproducible test-case. Is that true? If so, could you try it out on a more recent release (e.g. 2.4.0.Final)?