Async exclusive=true ! weird behavior in clustered mode!

Flowable Engine
1

Our environment:
JBoss 7.1.x - standalone-ha mode.
Flowable - 6.4.0
MS-SQLServer
ActiveMQ - for service task/long-running task
Design wise, most of the BPMN activities are defined as async and exclusive.

Behavior/Identified Issues during peak hour:
found the async job executor race condition higher, it creates issues like,

  1. Task creation/execution duplicated more than twice
  2. Call activity/ Service Task/SubProcesses skipped - Some subprocess will skip and it will go to the next step in the process

Resolution:

  1. Keeping Job executor active only in one node. eg.
    Node 1 - flowable-async-executor-activate=true
    Node 2 - flowable-async-executor-activate=false
  2. long term solution could be: move Async operation to JMS queue (https://www.flowable.org/docs/userguide/index.html#_message_queue_based_async_executor)

Please share your suggestions!!
Thanks
Prakie.