Running two java services pointing to single flowable database

Flowable Engine
1

Hi,

We are using flowable 6.4.0 as our BPMN engine. Our application consumes JMS event and triggers flowable process that has multiple service tasks, wait timer and exclusive gateways to decide and follow correct business process path. Currently our java service is running in test and it running with single instance. Soon we want to deploy it to production and there is possibility to run our java service with multiple instances ( on separate nodes/servers to support main and failover), so will there be any issues if we run our java service with multiple instance and shared flowable database?
So question / concern I have is,

  1. We have timer wait activity that waits for a day and then resume pending tasks, in case of two instances of same java services, will both java services pick the waiting task and execute it?.
    If yes, should we run with only single instance or is there a way to restrict task execution on only one java service instance?
    So basically I am not sure how flowable behaves in case of two or more instances of a same service, in a microservices (same service with multiple instances) kind of setup?

Thanks,
Vijay Chavan

2

Is there a reason for not using the latest version (6.6.0)? 6.4.0 is quite old and many bugs have been fixed and improvements have been added since.

No, Flowable has been designed for exactly this scenario.

No, timer events are picked up, locked and executed by a single node.

3

@joram thanks for you inputs. There is no any reason for using 6.4.0, but this is existing service and we just need to priorities and do the migration to 6.6.0.