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MAPREDUCE-7028. Concurrent task progress updates causing NPE in Application Master. Contributed by Gergo Repas

This commit is contained in:
Jason Lowe 2018-01-03 11:01:38 -06:00
parent c9bf813c9a
commit fe35103591
1 changed files with 23 additions and 18 deletions
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41
hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapred/TaskAttemptListenerImpl.java
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@ -585,33 +585,38 @@ public class TaskAttemptListenerImpl extends CompositeService
private void coalesceStatusUpdate(TaskAttemptId yarnAttemptID,
TaskAttemptStatus taskAttemptStatus,
AtomicReference<TaskAttemptStatus> lastStatusRef) {
boolean asyncUpdatedNeeded = false;
TaskAttemptStatus lastStatus = lastStatusRef.get();
if (lastStatus == null) {
lastStatusRef.set(taskAttemptStatus);
asyncUpdatedNeeded = true;
} else {
List<TaskAttemptId> oldFetchFailedMaps =
taskAttemptStatus.fetchFailedMaps;
// merge fetchFailedMaps from the previous update
if (lastStatus.fetchFailedMaps != null) {
List<TaskAttemptId> fetchFailedMaps = taskAttemptStatus.fetchFailedMaps;
TaskAttemptStatus lastStatus = null;
boolean done = false;
while (!done) {
lastStatus = lastStatusRef.get();
if (lastStatus != null && lastStatus.fetchFailedMaps != null) {
// merge fetchFailedMaps from the previous update
if (taskAttemptStatus.fetchFailedMaps == null) {
taskAttemptStatus.fetchFailedMaps = lastStatus.fetchFailedMaps;
} else {
taskAttemptStatus.fetchFailedMaps.addAll(lastStatus.fetchFailedMaps);
taskAttemptStatus.fetchFailedMaps =
new ArrayList<>(lastStatus.fetchFailedMaps.size() +
fetchFailedMaps.size());
taskAttemptStatus.fetchFailedMaps.addAll(
lastStatus.fetchFailedMaps);
taskAttemptStatus.fetchFailedMaps.addAll(
fetchFailedMaps);
}
}
if (!lastStatusRef.compareAndSet(lastStatus, taskAttemptStatus)) {
// update failed - async dispatcher has processed it in the meantime
taskAttemptStatus.fetchFailedMaps = oldFetchFailedMaps;
lastStatusRef.set(taskAttemptStatus);
asyncUpdatedNeeded = true;
// lastStatusRef may be changed by either the AsyncDispatcher when
// it processes the update, or by another IPC server handler
done = lastStatusRef.compareAndSet(lastStatus, taskAttemptStatus);
if (!done) {
LOG.info("TaskAttempt " + yarnAttemptID +
": lastStatusRef changed by another thread, retrying...");
// let's revert taskAttemptStatus.fetchFailedMaps
taskAttemptStatus.fetchFailedMaps = fetchFailedMaps;
}
}
boolean asyncUpdatedNeeded = (lastStatus == null);
if (asyncUpdatedNeeded) {
context.getEventHandler().handle(
new TaskAttemptStatusUpdateEvent(taskAttemptStatus.id,