Thanks, now I pretty much understood what you try to achieve.
Just one last question - are you going to use persistence of your sessions (StatefulKnowledgeSession)?
If so, you need to make sure that particular session will be loaded from db only by one server to avoid troubles when persisting sessions (potential overriding each other). You mentioned that:
Morioka Ryoichi wrote:
When web app recieve user's request, web app send the msg to BPM engine. And BPM engine execute "making new session of the flow" or "starting and completing the task".
so every request will create new session? One option would be to correlate userId with session so every user will have its own session that will be bound to session life cycle of the web application, and problem with same session loaded on both servers will be solved if your load balancer will use "sticky sessions".
Another thing, if you consider to have task service and jbpm engine running in the same JVM, you should take a look at latest implementation of local task service so you will not execute it over the network (for instance mina). It should be released with 5.2 version but it is already available as nightly build.
Hope this helps