Limit number of concurrently running instances of a process definition

StephenOTT · November 16, 2016, 6:18pm

This may be a bit “hackish”?

But could you just create a script on the Start Event: Start Listener:

var instances = execution.getProcessEngineServices().getRuntimeService().createProcessInstanceQuery().processDefinitionKey("concurrentTest").active().count();

execution.setVariable("instances", instances);

if (instances > 1) {
   throw "too many instances are running";
}

and if you run through tasklist:

and through the API:

Note: the variable being set in the script is just for testing and seeing what was going on.