Process hangs on serviceTask

I have a process definition that does a bunch of userTasks and serviceTasks, and in the end there are about 3 serviceTasks in sequence that do various logging/http calls etc.

We have noticed that somewhat intermittently our process instance will get stuck on the last serviceTask in the flow. The code in the serviceTask is never executed and looking at the act_ru_execution table it shows an execution entry for the serviceTask but the is_active_ flag is false.

This serviceTask is not async and the serviceTask just before it successfully executes and I see a entry in the act_hi_actinst table for the prior serviceTask.

There is nothing in the logs to indicate any exception or error. It just never kicked off executing the serviceTask.

Any hints/ideas or let me know if I need to provide further information? It seems simple enough and I know it’s probably not a bug in flowable and something to do with how we are doing things.


The only advice which I have is to debug execution and make some experiments. e.g. put “non executed” task to the beginning of the sequence…
In the case when all these debugging sessions and experiments fail try to create jUnit test to communicate issue.