[SPARK-2886] Use more specific actor system name than "spark"

As of #1777 we log the name of the actor system when it binds to a port. The current name "spark" is super general and does not convey any meaning. For instance, the following line is taken from my driver log after setting `spark.driver.port` to 5001.
```
14/08/13 19:33:29 INFO Remoting: Remoting started; listening on addresses:
[akka.tcp://sparkandrews-mbp:5001]
14/08/13 19:33:29 INFO Remoting: Remoting now listens on addresses:
[akka.tcp://sparkandrews-mbp:5001]
14/08/06 13:40:05 INFO Utils: Successfully started service 'spark' on port 5001.
```
This commit renames this to "sparkDriver" and "sparkExecutor". The goal of this unambitious PR is simply to make the logged information more explicit without introducing any change in functionality.

Author: Andrew Or <andrewor14@gmail.com>

Closes #1810 from andrewor14/service-name and squashes the following commits:

8c459ed [Andrew Or] Use a common variable for driver/executor actor system names
3a92843 [Andrew Or] Change actor name to sparkDriver and sparkExecutor
921363e [Andrew Or] Merge branch 'master' of github.com:apache/spark into service-name
c8c6a62 [Andrew Or] Do not include hyphens in actor name
1c1b42e [Andrew Or] Avoid spaces in akka system name
f644b55 [Andrew Or] Use more specific service name

5 files changed, 22 insertions, 13 deletions

diff --git a/core/src/main/scala/org/apache/spark/SparkEnv.scala b/core/src/main/scala/org/apache/spark/SparkEnv.scala
index fc36e37c53..72716567ca 100644
--- a/core/src/main/scala/org/apache/spark/SparkEnv.scala
+++ b/core/src/main/scala/org/apache/spark/SparkEnv.scala
@@ -111,6 +111,9 @@ object SparkEnv extends Logging {
   private val env = new ThreadLocal[SparkEnv]
   @volatile private var lastSetSparkEnv : SparkEnv = _
 
+  private[spark] val driverActorSystemName = "sparkDriver"
+  private[spark] val executorActorSystemName = "sparkExecutor"
+
   def set(e: SparkEnv) {
     lastSetSparkEnv = e
     env.set(e)
@@ -146,9 +149,9 @@ object SparkEnv extends Logging {
     }
 
     val securityManager = new SecurityManager(conf)
-
-    val (actorSystem, boundPort) = AkkaUtils.createActorSystem("spark", hostname, port, conf = conf,
-      securityManager = securityManager)
+    val actorSystemName = if (isDriver) driverActorSystemName else executorActorSystemName
+    val (actorSystem, boundPort) = AkkaUtils.createActorSystem(
+      actorSystemName, hostname, port, conf, securityManager)
 
     // Figure out which port Akka actually bound to in case the original port is 0 or occupied.
     // This is so that we tell the executors the correct port to connect to.
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/SimrSchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/SimrSchedulerBackend.scala
index d99c76117c..4f7133c4bc 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/SimrSchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/SimrSchedulerBackend.scala
@@ -20,7 +20,7 @@ package org.apache.spark.scheduler.cluster
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.{Path, FileSystem}
 
-import org.apache.spark.{Logging, SparkContext}
+import org.apache.spark.{Logging, SparkContext, SparkEnv}
 import org.apache.spark.scheduler.TaskSchedulerImpl
 
 private[spark] class SimrSchedulerBackend(
@@ -38,8 +38,10 @@ private[spark] class SimrSchedulerBackend(
   override def start() {
     super.start()
 
-    val driverUrl = "akka.tcp://spark@%s:%s/user/%s".format(
-      sc.conf.get("spark.driver.host"), sc.conf.get("spark.driver.port"),
+    val driverUrl = "akka.tcp://%s@%s:%s/user/%s".format(
+      SparkEnv.driverActorSystemName,
+      sc.conf.get("spark.driver.host"),
+      sc.conf.get("spark.driver.port"),
       CoarseGrainedSchedulerBackend.ACTOR_NAME)
 
     val conf = new Configuration()
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala
index 589dba2e40..32138e5246 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/SparkDeploySchedulerBackend.scala
@@ -17,7 +17,7 @@
 
 package org.apache.spark.scheduler.cluster
 
-import org.apache.spark.{Logging, SparkConf, SparkContext}
+import org.apache.spark.{Logging, SparkConf, SparkContext, SparkEnv}
 import org.apache.spark.deploy.{ApplicationDescription, Command}
 import org.apache.spark.deploy.client.{AppClient, AppClientListener}
 import org.apache.spark.scheduler.{ExecutorExited, ExecutorLossReason, SlaveLost, TaskSchedulerImpl}
@@ -42,8 +42,10 @@ private[spark] class SparkDeploySchedulerBackend(
     super.start()
 
     // The endpoint for executors to talk to us
-    val driverUrl = "akka.tcp://spark@%s:%s/user/%s".format(
-      conf.get("spark.driver.host"), conf.get("spark.driver.port"),
+    val driverUrl = "akka.tcp://%s@%s:%s/user/%s".format(
+      SparkEnv.driverActorSystemName,
+      conf.get("spark.driver.host"),
+      conf.get("spark.driver.port"),
       CoarseGrainedSchedulerBackend.ACTOR_NAME)
     val args = Seq(driverUrl, "{{EXECUTOR_ID}}", "{{HOSTNAME}}", "{{CORES}}", "{{WORKER_URL}}")
     val extraJavaOpts = sc.conf.getOption("spark.executor.extraJavaOptions")
diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/CoarseMesosSchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/CoarseMesosSchedulerBackend.scala
index 9f45400bcf..f0172504c5 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/CoarseMesosSchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/CoarseMesosSchedulerBackend.scala
@@ -28,7 +28,7 @@ import org.apache.mesos.{Scheduler => MScheduler}
 import org.apache.mesos._
 import org.apache.mesos.Protos.{TaskInfo => MesosTaskInfo, TaskState => MesosTaskState, _}
 
-import org.apache.spark.{Logging, SparkContext, SparkException}
+import org.apache.spark.{Logging, SparkContext, SparkEnv, SparkException}
 import org.apache.spark.scheduler.TaskSchedulerImpl
 import org.apache.spark.scheduler.cluster.CoarseGrainedSchedulerBackend
 
@@ -130,7 +130,8 @@ private[spark] class CoarseMesosSchedulerBackend(
     }
     val command = CommandInfo.newBuilder()
       .setEnvironment(environment)
-    val driverUrl = "akka.tcp://spark@%s:%s/user/%s".format(
+    val driverUrl = "akka.tcp://%s@%s:%s/user/%s".format(
+      SparkEnv.driverActorSystemName,
       conf.get("spark.driver.host"),
       conf.get("spark.driver.port"),
       CoarseGrainedSchedulerBackend.ACTOR_NAME)
diff --git a/core/src/main/scala/org/apache/spark/util/AkkaUtils.scala b/core/src/main/scala/org/apache/spark/util/AkkaUtils.scala
index d6afb73b74..e2d32c859b 100644
--- a/core/src/main/scala/org/apache/spark/util/AkkaUtils.scala
+++ b/core/src/main/scala/org/apache/spark/util/AkkaUtils.scala
@@ -27,7 +27,7 @@ import akka.pattern.ask
 import com.typesafe.config.ConfigFactory
 import org.apache.log4j.{Level, Logger}
 
-import org.apache.spark.{SparkException, Logging, SecurityManager, SparkConf}
+import org.apache.spark.{Logging, SecurityManager, SparkConf, SparkEnv, SparkException}
 
 /**
  * Various utility classes for working with Akka.
@@ -192,10 +192,11 @@ private[spark] object AkkaUtils extends Logging {
   }
 
   def makeDriverRef(name: String, conf: SparkConf, actorSystem: ActorSystem): ActorRef = {
+    val driverActorSystemName = SparkEnv.driverActorSystemName
     val driverHost: String = conf.get("spark.driver.host", "localhost")
     val driverPort: Int = conf.getInt("spark.driver.port", 7077)
     Utils.checkHost(driverHost, "Expected hostname")
-    val url = s"akka.tcp://spark@$driverHost:$driverPort/user/$name"
+    val url = s"akka.tcp://$driverActorSystemName@$driverHost:$driverPort/user/$name"
     val timeout = AkkaUtils.lookupTimeout(conf)
     logInfo(s"Connecting to $name: $url")
     Await.result(actorSystem.actorSelection(url).resolveOne(timeout), timeout)