Multiple akka system in a single pc

Question

How can we run multiple akka nodes in a single pc? Currently, I've following in my application.conf file. For each system, I added different port numbers, but, I can't start more than one instance. Error says, Address already in use failed to bind.

application.conf file

remotelookup {
  include "common"

  akka {
    remote.server.port = 2500
    cluster.nodename = "n1"
  }
}

Update : multiple akka nodes means, I have different different stand alone server application, which will communicate to remote master node using akka.

If each system system has its own configuration with different settings, then it should work — 4lex1v, Jul 11 '13 at 08:25
Each actor system on the same machine must be configured with a unique port. — Patrik Nordwall, Jul 11 '13 at 09:34
@PatrikNordwall : I configured like that, not working, check my question. — Abimaran Kugathasan, Jul 11 '13 at 09:47
Are you sure you have the config right? I'm looking at the 2.0 series docs for Akka Remoting and the port config looks to be `akka.remote.netty.port`. If this property is not set, it will default to `2552` and if both of your servers are doing this then the second one won't start up. Let me know if this works and I will post as an answer. — cmbaxter, Jul 11 '13 at 12:10

score 12 · Answer 1 · answered Jul 11 '13 at 08:09

The approach we are using is:

Create different settings in your application.conf for each of the systems:

systemOne {
  akka {
    remote {
      enabled-transports = ["akka.remote.netty.tcp"]
      netty.tcp {
        hostname = ${public-hostname}
        port = 2552
      }
    }
  }
}

systemTwo {
  akka {
    remote {
      enabled-transports = ["akka.remote.netty.tcp"]
      netty.tcp {
        hostname = ${public-hostname}
        port = 2553
      }
    }
  }
}

Application.conf is the default config file, so in your settings module add configs for you systems:

object Configs {
  private val root = ConfigFactory.load()
  val one          = root.getConfig("systemOne")
  val two          = root.getConfig("systemTwo")
}

and then create systems with this configs:

val one = ActorSystem("SystemName", one)
val two = ActorSystem("AnotherSystemName", two)

Don't forget that system names must differ

That's all settings necessary for starting new ActorSystem, which version of Akka do u use? — 4lex1v, Jul 11 '13 at 08:39

sourcedelica · Answer 2 · 2015-12-10T14:24:40.393

2

If you don't want to hardcode the info into your application.conf, you can do this:

def remoteConfig(hostname: String, port: Int, commonConfig: Config): Config = {
  val configStr = s"""
   |akka.remote.netty.hostname = $hostname
   |akka.remote.netty.port = $port
  """.stripMargin

  ConfigFactory.parseString(configStr).withFallback(commonConfig)
}

Then use it like:

val appConfig = ConfigFactory.load
val sys1 = ActorSystem("sys1", remoteConfig(args(0), args(1).toInt, appConfig))
val sys2 = ActorSystem("sys2", remoteConfig(args(0), args(2).toInt, appConfig))

If you use 0 for the port Akka will assign a random port # to that ActorSystem.

edited Dec 10 '15 at 14:24

answered Jul 11 '13 at 18:24

sourcedelica

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If you do not want to hardcode it in your configuration hardcode it as code?! – scravy Dec 09 '15 at 16:46
That's just an example. The values could come from anywhere. I've made that more explicit. – sourcedelica Dec 10 '15 at 14:22

score 1 · Accepted Answer · answered Jul 11 '13 at 14:24

1

The problem was in the port definition. It should be like

remotelookup {
  include "common"

  akka {
    remote.netty.port = 2500
    cluster.nodename = "n1"
  }
}

Other wise, akka will take default port.

answered Jul 11 '13 at 14:24

Abimaran Kugathasan

31,165
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Multiple akka system in a single pc

3 Answers3