In Play 2.0, Play delegated all requests to go through an actor. It heavily depended on Akka’s future API and other parts. In Play 2.1, with the move of Akka’s future API into Scala 2.10, Play started depending less directly on Akka. It gets all it’s execution contexts from Akka, and provides integration with Akka, … Read more
Creating an ActorSystem is very expensive, so you want to avoid creating a new one each time you need it. Also your actors should run in the same ActorSystem, unless there is a good reason for them not to. The name of the ActorSystem is also part the the path to the actors that run … Read more
There are three ways this can be achieved: 1. Post Materialization with SourceQueue You can use Source.queue that materializes the Flow into a SourceQueue: case class Weather(zipCode : String, temperature : Double, raining : Boolean) val bufferSize = 100 //if the buffer fills up then this strategy drops the oldest elements //upon the arrival of … Read more
The sender() will be different on the receiving end. Message sends using tell (also known as !): A tells message M to B. B tells that message to C. C thinks the sender() of message M is B. Message sends using forward: A tells message M to B. B forwards that message to C. C … Read more
TL;DR; While the description of states and transitions is rather ambiguous in the OP, the status of the chosen implementation, its implications and those of alternatives can be addressed. The implementation at hand can count as an “actor per request” approach, as opposed to what more frequently can be found, where the state-machine actor buffers … Read more
I personally started with spray a long time ago and tried everything else there was out there for Scala. While Scala, spray, akka, shapeless, and scalaz certainly have a bit of a learning curve, once you start digging in and really learning how you are supposed to use the technologies, they make sense and I … Read more
A case class can take arguments, so each instance of that case class can be different based on the values of it’s arguments. A case object on the other hand does not take args in the constructor, so there can only be one instance of it (a singleton, like a regular scala object is). If … Read more
Apache Spark is actually built on Akka. Akka is a general purpose framework to create reactive, distributed, parallel and resilient concurrent applications in Scala or Java. Akka uses the Actor model to hide all the thread-related code and gives you really simple and helpful interfaces to implement a scalable and fault-tolerant system easily. A good … Read more
Well, you create an Actor for each instance of mutable state that you want to manage. In your case, that might be just one actor if my-resource is a single object and you want to treat each request serially – that easily ensures that you only return consistent states between modifications. If (more likely) you … Read more
From an Actor you can use self to get the ActorRef. val actorName = self.path.name http://doc.akka.io/api/akka/2.2.3/#akka.actor.Actor http://doc.akka.io/api/akka/2.2.3/#akka.actor.ActorRef http://doc.akka.io/api/akka/2.2.3/#akka.actor.ActorPath