Akka + scala reverse server error - scala

Question

I have the question
This is my server https://github.com/vladimirkozhaev/reverse-str
This is my client https://github.com/vladimirkozhaev/string-reverse-client
When I run the server with sbt run command then run following test
package org.reversestr.client
import org.scalatest.concurrent.PatienceConfiguration.Timeout
import org.scalatest.{FunSpecLike, Matchers}
import org.scalatest.concurrent.ScalaFutures
import scala.concurrent.duration._
class RClientIntegrationSpec extends FunSpecLike with Matchers with ScalaFutures {
val client:RClient = new RClient("127.0.0.1:2552")
describe("reverse str Scala Client") {
describe("set method") {
it("should set a value") {
whenReady(client.setStr("123"), Timeout(1 second)) {
r => r shouldBe "321"
}
}
}
}
}
Have this strange error message
Where I'm wrong?
[INFO] [09/30/2017 22:34:52.985] [pool-4-thread-9]
[akka.remote.Remoting] Starting remoting [ERROR] [09/30/2017
22:34:53.466] [LocalSystem-akka.remote.default-remote-dispatcher-13]
[NettyTransport(akka://LocalSys tem)] failed to bind to
/127.0.0.1:2552, shutting down Netty transport [ERROR] [09/30/2017
22:34:53.516] [pool-4-thread-9] [akka.remote.Remoting] Remoting error:
[Startup failed] [ akka.remote.RemoteTransportException: Startup
failed
at akka.remote.Remoting.akka$remote$Remoting$$notifyError(Remoting.scala:146)
at akka.remote.Remoting.start(Remoting.scala:212)
at akka.remote.RemoteActorRefProvider.init(RemoteActorRefProvider.scala:212)
at akka.actor.ActorSystemImpl.liftedTree2$1(ActorSystem.scala:796)
at akka.actor.ActorSystemImpl._start$lzycompute(ActorSystem.scala:793)
at akka.actor.ActorSystemImpl._start(ActorSystem.scala:793)
at akka.actor.ActorSystemImpl.start(ActorSystem.scala:809)
at akka.actor.ActorSystem$.apply(ActorSystem.scala:244)
at akka.actor.ActorSystem$.apply(ActorSystem.scala:287)
at akka.actor.ActorSystem$.apply(ActorSystem.scala:232)
at org.reversestr.client.RClient.(RClient.scala:11)
at org.reversestr.client.RClientIntegrationSpec.(RClientIntegrationSpec.scala:9)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.lang.Class.newInstance(Class.java:442)
at org.scalatest.tools.Framework$ScalaTestTask.execute(Framework.scala:646)
at sbt.TestRunner.runTest$1(TestFramework.scala:76)
at sbt.TestRunner.run(TestFramework.scala:85)
at sbt.TestFramework$$anon$2$$anonfun$$init$$1$$anonfun$apply$8.apply(TestFramework.scala:202)
at sbt.TestFramework$$anon$2$$anonfun$$init$$1$$anonfun$apply$8.apply(TestFramework.scala:202)
at sbt.TestFramework$.sbt$TestFramework$$withContextLoader(TestFramework.scala:185)
at sbt.TestFramework$$anon$2$$anonfun$$init$$1.apply(TestFramework.scala:202)
at sbt.TestFramework$$anon$2$$anonfun$$init$$1.apply(TestFramework.scala:202)
at sbt.TestFunction.apply(TestFramework.scala:207)
at sbt.Tests$$anonfun$9.apply(Tests.scala:216)
at sbt.Tests$$anonfun$9.apply(Tests.scala:216)
at sbt.std.Transform$$anon$3$$anonfun$apply$2.apply(System.scala:44)
at sbt.std.Transform$$anon$3$$anonfun$apply$2.apply(System.scala:44)
at sbt.std.Transform$$anon$4.work(System.scala:63)
at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
at sbt.Execute.work(Execute.scala:235)
at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745) Caused by: org.jboss.netty.channel.ChannelException: Failed to bind to:
/127.0.0.1:2552
at org.jboss.netty.bootstrap.ServerBootstrap.bind(ServerBootstrap.java:272)
at akka.remote.transport.netty.NettyTransport$$anonfun$listen$1.apply(NettyTransport.scala:417)
at akka.remote.transport.netty.NettyTransport$$anonfun$listen$1.apply(NettyTransport.scala:413)
at scala.util.Success$$anonfun$map$1.apply(Try.scala:236)
at scala.util.Try$.apply(Try.scala:191)
at scala.util.Success.map(Try.scala:236)
at scala.concurrent.Future$$anonfun$map$1.apply(Future.scala:235)
at scala.concurrent.Future$$anonfun$map$1.apply(Future.scala:235)
at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:32)
at akka.dispatch.BatchingExecutor$AbstractBatch.processBatch(BatchingExecutor.scala:55)
at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply$mcV$sp(BatchingExecutor.scala:91)
at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply(BatchingExecutor.scala:91)
at akka.dispatch.BatchingExecutor$BlockableBatch$$anonfun$run$1.apply(BatchingExecutor.scala:91)
at scala.concurrent.BlockContext$.withBlockContext(BlockContext.scala:72)
at akka.dispatch.BatchingExecutor$BlockableBatch.run(BatchingExecutor.scala:90)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:40)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(ForkJoinExecutorConfigurator.scala:43)
at akka.dispatch.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at akka.dispatch.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at akka.dispatch.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at akka.dispatch.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: java.net.BindException: Address already in use: bind
at sun.nio.ch.Net.bind0(Native Method)
at sun.nio.ch.Net.bind(Net.java:433)
at sun.nio.ch.Net.bind(Net.java:425)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
at org.jboss.netty.channel.socket.nio.NioServerBoss$RegisterTask.run(NioServerBoss.java:193)
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.processTaskQueue(AbstractNioSelector.java:391)
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:315)
at org.jboss.netty.channel.socket.nio.NioServerBoss.run(NioServerBoss.java:42)
at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108)
at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Answer 1

It seems there is already another application running at the specified port: 2552.
The exception clearly shows that: java.net.BindException: Address already in use:
The quick solution is to clear the port by killing the application that runs at that port.
To clear the port, execute the following command in your shell (or terminal):
kill -9 $(lsof -t -i:2552)
Then, retry running your test.
Explanation of the commands:
lsof -t -i:2552 returns the process id of the application that runs on port 2552
kill -9 process_id kills the application with given process id