Akka FSM actor and round-robin routing

Question

I want to convert some set of actors into FSM using Akka FSM. Currently system is designed in the way that every actor knows what to do with results of it's action and which actor is next in sequence of processing.

Now I want to have some sort of dedicated actors, which are doing only things they should know (and now know about entire message routing), and central FSM, which knows how to route messages and process transformation flow.

Client sends some request to FSM actor, FSM actor - on transition to next state - sends message to some actor in onTransition block. That actor replies to sender with some message, which is processed inside FSM state somehow until request is finished.

So far everything looks good, however I'm not sure what will happen if multiple clients will start interaction with FSM actor. Will the "workflow" be recorded somewhere, so flows from different clients won't collide at some point (like, FSM actor receives message from another client instead of originating one)?

Is it safe to have say 10 FSM actors and round-robin router, or I need to create new FSM actor on every request from client, and then kill it once finished?

Answer 1

Each Akka FSM actor will have only one state at a time, so you can't use multiple FSM actors with a round-robin router in this scenario. You may consider to create a new FSM actor on every request from a client. There are other options (a shared multi-user non-Akka FSM and a pool of FSM actors which may be "busy") but creation of a per-user FSM should be better solution because of the light-weight nature of Akka actors.