From 0768f96a833c16bf6136253d9ed846c72c4565bc Mon Sep 17 00:00:00 2001
From: Thomas White <tomwhite@apache.org>
Date: Thu, 3 Jan 2013 15:07:22 +0000
Subject: [PATCH] YARN-300. After YARN-271, fair scheduler can infinite loop
 and not schedule any application. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1428387 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-yarn-project/CHANGES.txt                                | 3 +++
 .../server/resourcemanager/scheduler/fair/FairScheduler.java   | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 293875d3f07..7f4a8742001 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -161,6 +161,9 @@ Release 2.0.3-alpha - Unreleased
     YARN-288. Fair scheduler queue doesn't accept any jobs when ACLs are
     configured. (Sandy Ryza via tomwhite)
 
+    YARN-300. After YARN-271, fair scheduler can infinite loop and not
+    schedule any application. (Sandy Ryza via tomwhite)
+
 Release 2.0.2-alpha - 2012-09-07 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java
index 305a23527c6..c31a2dbb740 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java
@@ -760,7 +760,7 @@ private synchronized void nodeUpdate(RMNode nm,
     // Otherwise, schedule at queue which is furthest below fair share
     else {
       int assignedContainers = 0;
-      while (true) {
+      while (node.getReservedContainer() == null) {
         // At most one task is scheduled each iteration of this loop
         List<FSLeafQueue> scheds = new ArrayList<FSLeafQueue>(
             queueMgr.getLeafQueues());