Description:
TIBCO BusinessWorks™ ProcessMonitor (BWPM)  Client blocks the TIBCO BusinessWorks™ (BW) engine when TIBCO Enterprise Message Service™ (EMS) server is down or the connection is not reliable. This issue is encountered when the internal queue (maxQueueLength) value is exceeded. The maxQueueLength is a setting for the internal queue of the BWPM Client, which is a pipeline for internal job elements and cannot be compared with a number of BW jobs created. It has no relation with BW jobs queues.

Steps to reproduce the issue:

1). Create simple BW process with any activities (like "Timer", "Write To Log").
2). Run the project in Designer or deploy it on the Admin domain. Make sure the EMS server is running.
3). Create BW jobs. You will see that BWPM events are published on BWMP queue.
4). Stop the EMS server.
5). You will observe that after some jobs are created, the BW engine will stop completing the jobs and will remain in an active state.
6). There will be no logs entries recorded in the BW engine logs. Jobs will keep on creating (verify the behavior in Admin GUI->BW Service->General tab->Current process value will keep increasing).
Symptoms:
When a TIBCO BusinessWorks™ ProcessMonitor (BWPM) Client blocks the TIBCO BusinessWorks™ (BW) engine, BW jobs are created based on incoming requests or messages but jobs are not completed. You will observe BW jobs are in an active state in the Admin GUI and there will be no logs recorded in the BW engine logs and no BWPM event messages will be publish.
Cause:
When a TIBCO BusinessWorks™ ProcessMonitor (BWPM) Client blocks the TIBCO BusinessWorks™ (BW) engine when an internal queue parameter (maxQueueLength - default value is 20) is exceeded.

If the TIBCO Enterprise Message Service™ (EMS) Server is not available, TIBCO BusinessWorks™ ProcessMonitor (BWPM) Client will block the TIBCO BusinessWorks™ (BW) Engine when the internal queue is exceeded. This is the default behavior of a BWPM Client. To avoid this situation, you have to enable the "tibco.clientVar.nJAMS/MemoryManagement/discardPolicy=discard" parameter in the deployed/bwengine tra file. This parameter will unblock the BW engine, but the bwpm event will not get publish. Make sure an EMS server is up and running so that the maxQueueLength value will not be exceeded, the BW engine will not block, and events are not discarded.

TIBCO BusinessWorks™ ProcessMonitor (BWPM) Client blocks the TIBCO BusinessWorks™ (BW) engine when the TIBCO Enterprise Message Service™ (EMS) server is down or the connection is unreliable.