Queries about Parallel Execution in Activiti

[sharad]

I have gone through http://bpmn20inaction.blogspot.in/2012/12/implement-parallel-execution-in-activiti.html link and implemented at our end. I have few queries about Parallel Execution

1. You have mention Camel Integration for resolving Optimistic Exception during parallel execution. Here I did not see any attachment with process instance id with Camel Seda Queues. Suppose I want to run multiple instances of Parallel workflow that have camel integration. Does it work successfully ? If not, Is there any way to run successful Parallel Tasks in multiple instance scenario ?

2. If we do not integrate parallel workflow with camel integration then optimistic exception occur. Do you have any other way to resolve this issue ?

3. Can optimistic exception remove using pessimistic locking ?

4. Does Camel Integration also help for resolving optimistic exception in other case ? Please tell those scenarios.

[trademak]

1. process instance id is available in the Camel context by default when sending a message to a Camel queue. That's implemented in the Activiti Camel module
2. so you have a couple of service tasks executing in parallel and next a parallel gateway join? You can set the service tasks to run exclusive, but then they don't run in parallel anymore. Another solution is not available to my knowledge.
3. Activiti uses optimistic locking, and pessimistic locking is not really considered a good practice in general anymore.
4. It solves the potential optimistic lock exception for parallel join gateways and multi instance activities.

Best regards,