Camunda fails to create process instances

Camunda 7 Topics Discussion & Questions
1

Hi folks

We have a production system using Camunda ver. 7.2.0 (as spring application) running on Linux JBoss 6.4 cluster with two nodes running for a bit more than one year. There is nothing out of the ordinary in terms of the setup. No default setup were modified.

                       // Default to generic workflow if variable map is empty
			   if (null == workflowVariableMap) {
    				workflowVariableMap = populateGenricWorkflowVaribaleMap(application);
    				runtimeService.startProcessInstanceByKey(processKey, workflowVariableMap);
    			} else {
    				// start the workflow with the assigned process key
    				runtimeService.startProcessInstanceByKey(processKey, workflowVariableMap);
    			}

We have been noticing (only in Production) that process instances are not getting created for around 5% of the applications. Other application data is persisted however there is no workflow instance including in Camunda history tables. I am thinking that they Camunda failed to get executed.

My questions are

  1. Have anyone faced similar problems?
  2. If so, what was going wrong?
  3. Could this be a thread pool issue? I read somewhere in the forum that there is only upto 3 threads in the job acquisition pool. But what about job executer thread? Does it have a threashold on no. of applications that it can handle concurrently?
  4. Are there any settings that I can override?

I do apologise if I asked a lot. But I am trying to get your thinking around all probable issues that can lead to this issue.

Regards
Prad

2

Hi @prad,

2.have you checked the logs? Do you observe any exceptions there at the time when the processes should have been started?
3.why do you think it can be a thread pool issues? As I see you are starting process instance explicitly. Job acquisition could be involved here in case, when your process starts with the timer start event. Anyway pool size means only how many jobs can be executed simultaneously, but the others won’t be “rejected” forever, they will just wait till the threads are available again.