Stuck job instance due to ActivitiOptimisticLockingException

[holysoul]

Hi all.
I got this problem, (just look like in this jira ticket, please check it http://jira.codehaus.org/browse/ACT-1853 )
And I could describe it like that:

I encountered multiple stuck instances in ACT_RU_JOB where an async-continuation is attempting to proceed to the next step, encountering ActivitiOptimisticLockingException

Summary:

Basically task A routes directly to task B
Task A is an asynchronous task
Task B is a user task
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And here is exception when I start Instance

ERROR - ExecuteJobsRunnable.handleMultipleJobs(96) | exception during job execution: ProcessInstance[122907] was updated by another transaction concurrently
org.activiti.engine.ActivitiOptimisticLockingException: ProcessInstance[122907] was updated by another transaction concurrently
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Please help me, how to solve this exception.

[holysoul]

I had changed logic of service task, the Thread.sleep() is from 5s to 100ms, so there is no exception at all. Is the error related to job's time out?

[holysoul]

Sorry guys, I have figured it out. It caused by I have multiple engines which 2 of them already activated jobs. So I just turn off 1.