UIMA AS aggregate disables broker connection

One of the users reported a problem which seems like a bug in the UIMA AS code which detects status of a broker connection. The user provided description follows:

I have an aggregate AE with a remote primitive (OntoAnnotator). Both have
their queues at the same broker. Clients send requests to the aggregate
using the sendCAS() method.

This was running fine for about 5-6 hours, but then the aggregate logged an
error:
11/10/04 02:00:12 INFO cpe.DynamicFlowController$DynamicFlow: Next Executing
Annotator :: OntoAnnotator
11/10/04 02:00:12 INFO activemq.JmsOutputChannel: Controller
AnalysisAggregator Invalidating JMS Connection To Broker
tcp://broker_ip:61616 and Closing Sessions To Delegates

It had received 4-5 timeouts from the remote delegate over time, but at
least a couple of hours before the above log. Both the broker and the remote
delegate were still running and had not crashed.

The aggregate continued processing requests after that – the CASes are
processed by all collocated primitives but not the remote one. Each CAS
process request gets an exception:
11/10/04 02:00:12 WARN
activemq.JmsEndpointConnection_impl:
org.apache.uima.aae.error.DelegateConnectionLostException:
Controller:AnalysisAggregator Lost Connection to Delegate:OntoAnnotator
at
org.apache.uima.adapter.jms.activemq.JmsEndpointConnection_impl.send(JmsEndpointConnection_impl.java:547)
at
org.apache.uima.adapter.jms.activemq.JmsEndpointConnection_impl.send(JmsEndpointConnection_impl.java:509)
at
org.apache.uima.adapter.jms.activemq.JmsOutputChannel.dispatch(JmsOutputChannel.java:1366)
at
org.apache.uima.adapter.jms.activemq.JmsOutputChannel.sendCasToRemoteEndpoint(JmsOutputChannel.java:1527)
at
org.apache.uima.adapter.jms.activemq.JmsOutputChannel.serializeCasAndSend(JmsOutputChannel.java:658)
at
org.apache.uima.adapter.jms.activemq.JmsOutputChannel.sendRequest(JmsOutputChannel.java:610)
at
org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.dispatch(AggregateAnalysisEngineController_impl.java:2395)
at
org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.dispatchProcessRequest(AggregateAnalysisEngineController_impl.java:2435)
at
org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.simpleStep(AggregateAnalysisEngineController_impl.java:1295)
at
org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.executeFlowStep(AggregateAnalysisEngineController_impl.java:2316)
at
org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.process(AggregateAnalysisEngineController_impl.java:1230)
at
org.apache.uima.aae.handler.HandlerBase.invokeProcess(HandlerBase.java:118)
at
org.apache.uima.aae.handler.input.ProcessResponseHandler.cancelTimerAndProcess(ProcessResponseHandler.java:108)

When I tried stopping the aggregate, the logs said the following though
there was no CAS request in process:
11/10/04 10:18:18 WARN service.UIMA_Service: Uima AS Service
AnalysisAggregator Caught Kill Signal - Initiating Quiesce and Stop
11/10/04 10:18:18 INFO controller.BaseAnalysisEngineController: Stopping
Controller: AnalysisAggregator
11/10/04 10:18:18 INFO activemq.JmsInputChannel: Stopping Service JMS
Transport. Service: q_async_ae
11/10/04 10:18:18 INFO activemq.JmsInputChannel: Controller:
AnalysisAggregator Stopped Listener on Endpoint: queue://q_async_ae
Selector: Selector:Command=2000 OR Command=2002.
11/10/04 10:18:18 INFO activemq.JmsInputChannel: Stopping Service JMS
Transport. Service: q_async_ae
11/10/04 10:18:18 INFO activemq.JmsInputChannel: Controller:
AnalysisAggregator Stopped Listener on Endpoint: queue://q_async_ae
Selector: Selector:Command=2001.
11/10/04 10:18:18 INFO controller.BaseAnalysisEngineController: Controller:
AnalysisAggregator Registering onEmpty Callback With InProcessCache.
11/10/04 10:18:18 INFO controller.BaseAnalysisEngineController: Controller:
AnalysisAggregator Awaiting onEmpty Callback From InProcessCache

After restarting just the aggregate, it connected to the remote AE just
fine. So i'm wondering why the aggregate decided to stop communicating with
it earlier?

I've seen a previous thread with a similar error (
http://thread.gmane.org/gmane.comp.apache.uima.general/3351/focus=3388), but
there the broker was wilfully taken down, whereas I did no such thing.

Thanks, and sorry for the barrage of info.

Meghana