Fixing #648 Adding support for configuring Netty backlog in akka config

akka-remote/src/main/scala/akka/remote/RemoteShared.scala

@@ -42,6 +42,8 @@ object RemoteServerSettings {
     level
   }
 
+  val BACKLOG = config.getInt("akka.remote.server.backlog", 4096)
+
   val SECURE = {
     /*if (config.getBool("akka.remote.ssl.service",false)) {
       val properties = List(

akka-remote/src/main/scala/akka/remote/netty/NettyRemoteSupport.scala

@@ -547,6 +547,7 @@ class NettyRemoteServer(serverModule: NettyRemoteServerModule, val host: String,
 
   val pipelineFactory = new RemoteServerPipelineFactory(name, openChannels, loader, serverModule)
   bootstrap.setPipelineFactory(pipelineFactory)
+  bootstrap.setOption("backlog", RemoteServerSettings.BACKLOG)
   bootstrap.setOption("child.tcpNoDelay", true)
   bootstrap.setOption("child.keepAlive", true)
   bootstrap.setOption("child.reuseAddress", true)

config/akka-reference.conf

@@ -128,6 +128,7 @@ akka {
       connection-timeout = 1
       require-cookie = on          # Should the remote server require that it peers share the same secure-cookie (defined in the 'remote' section)?
       untrusted-mode = off         # Enable untrusted mode for full security of server managed actors, allows untrusted clients to connect.
+      backlog = 4096               # Sets the size of the connection backlog
     }
 
     client {