From ee70585289ca7a5d0229934af000e8f45c7bc6ec Mon Sep 17 00:00:00 2001
From: Andrew Kyle Purtell <apurtell@apache.org>
Date: Mon, 22 Mar 2010 18:20:47 +0000
Subject: [PATCH] HBASE-2355 Unsynchronized logWriters map is mutated from
 several threads in HLog splitting

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@926242 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                                    | 2 ++
 .../java/org/apache/hadoop/hbase/regionserver/wal/HLog.java    | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index f6a1e2c187f..2b01f8333ab 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -248,6 +248,8 @@ Release 0.21.0 - Unreleased
                speed (Paul Smith via Stack)
    HBASE-2336  Fix build broken with HBASE-2334 (Lars Francke via Lars George)
    HBASE-2283  row level atomicity (Kannan Muthukkaruppan via Stack)
+   HBASE-2355  Unsynchronized logWriters map is mutated from several threads in
+               HLog splitting (Todd Lipcon via Andrew Purtell)
 
   IMPROVEMENTS
    HBASE-1760  Cleanup TODOs in HTable
diff --git a/core/src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLog.java b/core/src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLog.java
index 09c9c0a400e..5bd3fdd7fff 100644
--- a/core/src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLog.java
+++ b/core/src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLog.java
@@ -1108,7 +1108,8 @@ public class HLog implements HConstants, Syncable {
     Path oldLogDir, final FileStatus[] logfiles, final FileSystem fs,
     final Configuration conf) throws IOException {
     final Map<byte [], WriterAndPath> logWriters =
-      new TreeMap<byte [], WriterAndPath>(Bytes.BYTES_COMPARATOR);
+      Collections.synchronizedMap(
+        new TreeMap<byte [], WriterAndPath>(Bytes.BYTES_COMPARATOR));
     List<Path> splits = null;
     
     // Number of threads to use when log splitting to rewrite the logs.