AnsweredAssumed Answered

Boundary signal causes: already taking a transition

Question asked by dengee on Dec 11, 2015
Latest reply on Dec 16, 2015 by dengee
Hi there,

We're using activiti since June and we have different running instances of several processes and everything works great.
But now, I have a problem - and I don't know if I missunderstand some parts of BPMN and/or the use case was not correctly modelled.

I stripped the problem down to the following model:

The idea is as follows:
- the "service task" checks if a certain file (e.g. example.gif) exists or not.
- if the file is missing, a human task is added, where someone has to add the file
- there are different instances and it is possible that these different instances wait for the same file.
- so, if one instance has added a file (the "add a file" was completed) - a signal is sent to all instances.
- this should cancel all "add a file" tasks from all remaining instances. so, the "service task" rechecks if the file for this instance now exists.

so - it's somekind of a "multi-instance-retry"

However, when I want to complete the "Add a file" task, a "org.activiti.engine.impl.pvm.PvmException: already taking a transition" is thrown.

version: activiti 5.19

Do I missunderstand the boundary and signal concepts?!