Github user pwendell commented on a diff in the pull request:
https://github.com/apache/spark/pull/1056#discussion_r15273373
--- Diff: core/src/main/scala/org/apache/spark/executor/Executor.scala ---
@@ -348,4 +352,46 @@ private[spark] class Executor(
}
}
}
+
+ def stop() {
+ isStopped = true
+ threadPool.shutdown()
+ }
+
+ def startDriverHeartbeater() {
+ val interval = conf.getInt("spark.executor.heartbeatInterval", 2000)
+ val timeout = AkkaUtils.lookupTimeout(conf)
+ val retryAttempts = AkkaUtils.numRetries(conf)
+ val retryIntervalMs = AkkaUtils.retryWaitMs(conf)
+ val heartbeatReceiverRef =
AkkaUtils.makeDriverRef("HeartbeatReceiver", conf, env.actorSystem)
+
+ val t = new Thread() {
+ override def run() {
+ // Sleep a random interval so the heartbeats don't end up in sync
+ Thread.sleep(interval + (math.random * interval).asInstanceOf[Int])
+
+ while (!isStopped) {
+ val tasksMetrics = new ArrayBuffer[(Long, TaskMetrics)]()
+ for (taskRunner <- runningTasks.values()) {
+ Option(taskRunner.task).flatMap(_.metrics).foreach { metrics =>
+ tasksMetrics += ((taskRunner.taskId, metrics))
--- End diff --
The way this is designed it seems like the TaskMetrics objects will be
modified by the Executor while also being serialized by Akka to send over the
wire. Am I missing some synchronization or copying somewhere? Or are we
assuming that all the fields in TaskMetrics will be atomically set with
immutable objects?
What happens if someone adds a field to TaskMetrics that is mutable, e.g. a
HashMap or something, and then we are serializing it as we mutate it?
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