107 lines
3.1 KiB
ReStructuredText
107 lines
3.1 KiB
ReStructuredText
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.. _remoting-scala:
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#################
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Remoting (Scala)
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#################
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For an introduction of remoting capabilities of Akka please see :ref:`remoting`.
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Preparing your ActorSystem for Remoting
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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The Akka remoting is a separate jar file. Make sure that you have a dependency from your project to this jar::
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akka-remote.jar
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In you SBT project you should add the following as a dependency::
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"com.typesafe.akka" % "akka-remote" % "2.0-SNAPSHOT"
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First of all you have to change the actor provider from ``LocalActorRefProvider`` to ``RemoteActorRefProvider``::
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akka {
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actor {
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provider = "akka.remote.RemoteActorRefProvider"
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}
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}
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After that you must also add the following settings::
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akka {
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server {
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# The hostname or ip to bind the remoting to,
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# InetAddress.getLocalHost.getHostAddress is used if empty
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hostname = ""
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# The default remote server port clients should connect to.
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# Default is 2552 (AKKA)
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port = 2552
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}
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}
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These are the bare minimal settings that must exist in order to get started with remoting.
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There are, of course, more properties that can be tweaked. We refer to the following
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reference file for more information:
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* `reference.conf of akka-remote <https://github.com/jboner/akka/blob/master/akka-remote/src/main/resources/reference.conf#L39>`_
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Using Remote Actors
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^^^^^^^^^^^^^^^^^^^
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The configuration below instructs the system to deploy the actor "retrieval” on the specific host "app@10.0.0.1".
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The "app" in this case refers to the name of the ``ActorSystem``::
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akka {
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actor {
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deployment {
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/serviceA/retrieval {
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remote = “akka://app@10.0.0.1:2552”
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}
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}
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}
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}
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Logical path lookup is supported on the node you are on, i.e. to use the
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actor created above you would do the following::
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val actor = context.actorFor("/serviceA/retrieval")
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This will obtain an ``ActorRef`` on a remote node::
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val actor = context.actorFor("akka://app@10.0.0.1:2552/user/serviceA/retrieval")
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As you can see from the example above the following pattern is used to find an ``ActorRef`` on a remote node::
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akka://<actorsystemname>@<hostname>:<port>/<actor path>
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Serialization
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^^^^^^^^^^^^^
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When using remoting for actors you must ensure that the ``props`` and ``messages`` used for
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those actors are serializable. Failing to do so will cause the system to behave in an unintended way.
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For more information please see :ref:`serialization-scala`
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Routers with Remote Destinations
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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It is absolutely feasible to combine remoting with :ref:`routing-scala`.
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This is also done via configuration::
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akka {
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actor {
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deployment {
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/serviceA/aggregation {
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router = “round-robin”
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nr-of-instances = 10
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target {
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nodes = [“akka://app@10.0.0.2:2552”, “akka://app@10.0.0.3:2552”]
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}
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}
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}
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}
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}
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This configuration setting will clone the actor “aggregation” 10 times and deploy it evenly distributed across
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the two given target nodes.
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