UIMA-AS: sendAndRecieveCAS hangs with no response

[Aiman]

Hello all -

I have been able to successfully deploy my pipeline using UIMA-AS, I 
tested it through command line tools and received the output CAS. I was 
then able to programmatically call the service using Client API both 
asynchronous and synchronously. However, for some reason, after few 
runs it stopped working.

Now whenever I call sendAndReceiveCAS it just blocks without receiving 
any response, viewing uima.log did not help as I only found some INFO 
messages without any errors. sendCAS is more of a hit and miss, it 
works sometimes and sometimes it does not. I do not understand what 
causing this and I don't know how to troubleshoot it. I've tried to 
purge activemq queue, restart it, restart the AS service, changed the 
queue name. But none of that helped. When I try to terminate the 
service (using s+Enter), it also hangs after showing a few lines of 
"....... AnalysisEngineInstancePool.destroy() was called".

I know it's getting stuck somewhere, but my pipeline is very 
lightweight and it takes a few milliseconds directly without UIMA-AS. I 
would apperciate any help in troubleshooting this.

Thanks!