From 009af54d5192c822ba1299c1389e67266dfe7ad1 Mon Sep 17 00:00:00 2001
From: Thomas White <tomwhite@apache.org>
Date: Mon, 22 Apr 2013 20:07:06 +0000
Subject: [PATCH] MAPREDUCE-5146. application classloader may be used too early
 to load classes. Contributed by Sangjin Lee.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1470694 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-mapreduce-project/CHANGES.txt                      | 3 +++
 .../src/main/java/org/apache/hadoop/mapred/YarnChild.java | 8 +++-----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/hadoop-mapreduce-project/CHANGES.txt b/hadoop-mapreduce-project/CHANGES.txt
index cf6d4153cd..7236052f6c 100644
--- a/hadoop-mapreduce-project/CHANGES.txt
+++ b/hadoop-mapreduce-project/CHANGES.txt
@@ -330,6 +330,9 @@ Release 2.0.5-beta - UNRELEASED
     MAPREDUCE-5066. Added a timeout for the job.end.notification.url. (Ivan
     Mitic via acmurthy)
 
+    MAPREDUCE-5146. application classloader may be used too early to load
+    classes. (Sangjin Lee via tomwhite)
+
 Release 2.0.4-alpha - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapred/YarnChild.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapred/YarnChild.java
index 33ff626df3..27847889d7 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapred/YarnChild.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapred/YarnChild.java
@@ -20,10 +20,8 @@
 
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
-import java.io.PrintStream;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.security.PrivilegedExceptionAction;
@@ -148,6 +146,9 @@ public TaskUmbilicalProtocol run() throws Exception {
       // Add tokens to new user so that it may execute its task correctly.
       childUGI.addCredentials(credentials);
 
+      // set job classloader if configured before invoking the task
+      MRApps.setJobClassLoader(job);
+
       // Create a final reference to the task for the doAs block
       final Task taskFinal = task;
       childUGI.doAs(new PrivilegedExceptionAction<Object>() {
@@ -255,9 +256,6 @@ private static JobConf configureTask(Task task, Credentials credentials,
     final JobConf job = new JobConf(MRJobConfig.JOB_CONF_FILE);
     job.setCredentials(credentials);
 
-    // set job classloader if configured
-    MRApps.setJobClassLoader(job);
-
     String appAttemptIdEnv = System
         .getenv(MRJobConfig.APPLICATION_ATTEMPT_ID_ENV);
     LOG.debug("APPLICATION_ATTEMPT_ID: " + appAttemptIdEnv);