From c04a7d974aa5ae2589d36f63c4ac45fb42cd1b80 Mon Sep 17 00:00:00 2001
From: Tsz-wo Sze <szetszwo@apache.org>
Date: Fri, 2 Aug 2013 07:08:35 +0000
Subject: [PATCH] HDFS-5028. LeaseRenewer throws
 ConcurrentModificationException when timeout.  Contributed by zhaoyunjiong

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1509565 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt                   | 3 +++
 .../src/main/java/org/apache/hadoop/hdfs/LeaseRenewer.java    | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 21b5f79616..546fcef3e6 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -288,6 +288,9 @@ Release 2.1.1-beta - UNRELEASED
 
   BUG FIXES
 
+    HDFS-5028. LeaseRenewer throws ConcurrentModificationException when timeout.
+    (zhaoyunjiong via szetszwo)
+
 Release 2.1.0-beta - 2013-08-06
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/LeaseRenewer.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/LeaseRenewer.java
index 8f3b8fb0e3..24bdc2e05d 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/LeaseRenewer.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/LeaseRenewer.java
@@ -449,8 +449,8 @@ private void run(final int id) throws InterruptedException {
           LOG.warn("Failed to renew lease for " + clientsString() + " for "
               + (elapsed/1000) + " seconds.  Aborting ...", ie);
           synchronized (this) {
-            for(DFSClient c : dfsclients) {
-              c.abort();
+            while (!dfsclients.isEmpty()) {
+              dfsclients.get(0).abort();
             }
           }
           break;