MAPREDUCE-4400: Avoid task finish sleep to improve small job/workflow latency. (llu)
git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.1@1365851 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/CHANGES.txt b/CHANGES.txt
index 22e9dd8..5691478 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -143,6 +143,9 @@
MAPREDUCE-4399. Change the Jetty response buffer size to improve
shuffle performance. (Luke Lu via suresh)
+ MAPREDUCE-4400. Avoid task finish sleep to improve small job/workflow
+ latency. (llu)
+
BUG FIXES
MAPREDUCE-4087. [Gridmix] GenerateDistCacheData job of Gridmix can
diff --git a/src/mapred/org/apache/hadoop/mapred/Task.java b/src/mapred/org/apache/hadoop/mapred/Task.java
index cee40f3..6f7ab88 100644
--- a/src/mapred/org/apache/hadoop/mapred/Task.java
+++ b/src/mapred/org/apache/hadoop/mapred/Task.java
@@ -649,14 +649,19 @@
// get current flag value and reset it as well
boolean sendProgress = resetProgressFlag();
while (!taskDone.get()) {
- synchronized(lock) {
- done = false;
- }
try {
boolean taskFound = true; // whether TT knows about this task
// sleep for a bit
try {
- Thread.sleep(PROGRESS_INTERVAL);
+ synchronized(lock) {
+ done = false;
+ lock.wait(PROGRESS_INTERVAL);
+ if (taskDone.get()) {
+ done = true;
+ lock.notify();
+ return;
+ }
+ }
}
catch (InterruptedException e) {
if (LOG.isDebugEnabled()) {
@@ -724,6 +729,7 @@
// Updating resources specified in ResourceCalculatorPlugin
if (pingThread != null) {
synchronized(lock) {
+ lock.notify(); // wake up the wait in the while loop
while(!done) {
lock.wait();
}
