Renamed stageIdToActiveJob to jobIdToActiveJob.

This data structure was misused and, as a result, later renamed to an incorrect name.

This data structure seems to have gotten into this tangled state as a result of @henrydavidge using the stageID instead of the job Id to index into it and later @andrewor14 renaming the data structure to reflect this misunderstanding.

This patch renames it and removes an incorrect indexing into it.  The incorrect indexing into it meant that the code added by @henrydavidge to warn when a task size is too large (added here 5757993) was not always executed; this commit fixes that.

Author: Kay Ousterhout <kayousterhout@gmail.com>

Closes #301 from kayousterhout/fixCancellation and squashes the following commits:

bd3d3a4 [Kay Ousterhout] Renamed stageIdToActiveJob to jobIdToActiveJob.

Author: kayousterhout

core/src/main/scala/org/apache/spark/scheduler/DAGScheduler.scala

@@ -84,7 +84,7 @@ class DAGScheduler(
   private[scheduler] val stageIdToJobIds = new TimeStampedHashMap[Int, HashSet[Int]]
   private[scheduler] val stageIdToStage = new TimeStampedHashMap[Int, Stage]
   private[scheduler] val shuffleToMapStage = new TimeStampedHashMap[Int, Stage]
-  private[scheduler] val stageIdToActiveJob = new HashMap[Int, ActiveJob]
+  private[scheduler] val jobIdToActiveJob = new HashMap[Int, ActiveJob]
   private[scheduler] val resultStageToJob = new HashMap[Stage, ActiveJob]
   private[spark] val stageToInfos = new TimeStampedHashMap[Stage, StageInfo]
 
@@ -536,7 +536,7 @@ class DAGScheduler(
           listenerBus.post(SparkListenerJobStart(job.jobId, Array[Int](), properties))
           runLocally(job)
         } else {
-          stageIdToActiveJob(jobId) = job
+          jobIdToActiveJob(jobId) = job
           activeJobs += job
           resultStageToJob(finalStage) = job
           listenerBus.post(
@@ -559,7 +559,7 @@ class DAGScheduler(
         // Cancel all running jobs.
         runningStages.map(_.jobId).foreach(handleJobCancellation)
         activeJobs.clear()      // These should already be empty by this point,
-        stageIdToActiveJob.clear()   // but just in case we lost track of some jobs...
+        jobIdToActiveJob.clear()   // but just in case we lost track of some jobs...
 
       case ExecutorAdded(execId, host) =>
         handleExecutorAdded(execId, host)
@@ -569,7 +569,6 @@ class DAGScheduler(
 
       case BeginEvent(task, taskInfo) =>
         for (
-          job <- stageIdToActiveJob.get(task.stageId);
           stage <- stageIdToStage.get(task.stageId);
           stageInfo <- stageToInfos.get(stage)
         ) {
@@ -697,7 +696,7 @@ class DAGScheduler(
   private def activeJobForStage(stage: Stage): Option[Int] = {
     if (stageIdToJobIds.contains(stage.id)) {
       val jobsThatUseStage: Array[Int] = stageIdToJobIds(stage.id).toArray.sorted
-      jobsThatUseStage.find(stageIdToActiveJob.contains)
+      jobsThatUseStage.find(jobIdToActiveJob.contains)
     } else {
       None
     }
@@ -750,8 +749,8 @@ class DAGScheduler(
       }
     }
 
-    val properties = if (stageIdToActiveJob.contains(jobId)) {
-      stageIdToActiveJob(stage.jobId).properties
+    val properties = if (jobIdToActiveJob.contains(jobId)) {
+      jobIdToActiveJob(stage.jobId).properties
     } else {
       // this stage will be assigned to "default" pool
       null
@@ -827,7 +826,7 @@ class DAGScheduler(
                   job.numFinished += 1
                   // If the whole job has finished, remove it
                   if (job.numFinished == job.numPartitions) {
-                    stageIdToActiveJob -= stage.jobId
+                    jobIdToActiveJob -= stage.jobId
                     activeJobs -= job
                     resultStageToJob -= stage
                     markStageAsFinished(stage)
@@ -986,11 +985,11 @@ class DAGScheduler(
       val independentStages = removeJobAndIndependentStages(jobId)
       independentStages.foreach(taskScheduler.cancelTasks)
       val error = new SparkException("Job %d cancelled".format(jobId))
-      val job = stageIdToActiveJob(jobId)
+      val job = jobIdToActiveJob(jobId)
       job.listener.jobFailed(error)
       jobIdToStageIds -= jobId
       activeJobs -= job
-      stageIdToActiveJob -= jobId
+      jobIdToActiveJob -= jobId
       listenerBus.post(SparkListenerJobEnd(job.jobId, JobFailed(error, job.finalStage.id)))
     }
   }
@@ -1011,7 +1010,7 @@ class DAGScheduler(
       val error = new SparkException("Job aborted: " + reason)
       job.listener.jobFailed(error)
       jobIdToStageIdsRemove(job.jobId)
-      stageIdToActiveJob -= resultStage.jobId
+      jobIdToActiveJob -= resultStage.jobId
       activeJobs -= job
       resultStageToJob -= resultStage
       listenerBus.post(SparkListenerJobEnd(job.jobId, JobFailed(error, failedStage.id)))

core/src/test/scala/org/apache/spark/scheduler/DAGSchedulerSuite.scala

@@ -428,7 +428,7 @@ class DAGSchedulerSuite extends FunSuite with BeforeAndAfter with LocalSparkCont
     assert(scheduler.pendingTasks.isEmpty)
     assert(scheduler.activeJobs.isEmpty)
     assert(scheduler.failedStages.isEmpty)
-    assert(scheduler.stageIdToActiveJob.isEmpty)
+    assert(scheduler.jobIdToActiveJob.isEmpty)
     assert(scheduler.jobIdToStageIds.isEmpty)
     assert(scheduler.stageIdToJobIds.isEmpty)
     assert(scheduler.stageIdToStage.isEmpty)