From f05b600cf4966c6d31bac589907790465b3ef22b Mon Sep 17 00:00:00 2001
From: ramkrishna <ramkrishna@unknown>
Date: Thu, 31 May 2012 17:05:59 +0000
Subject: [PATCH] HBASE-6089 SSH and AM.joinCluster causes Concurrent
 Modification exception. (Rajesh)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1344816 13f79535-47bb-0310-9956-ffa450edef68
---
 .../hbase/master/AssignmentManager.java       | 34 +++++++++----------
 .../apache/hadoop/hbase/master/HMaster.java   |  1 -
 .../hadoop/hbase/master/MasterFileSystem.java |  2 --
 3 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java
index 6013463e03b..dfae608ed8d 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java
@@ -358,7 +358,6 @@ public class AssignmentManager extends ZooKeeperListener {
   /**
    * Called on startup.
    * Figures whether a fresh cluster start of we are joining extant running cluster.
-   * @param onlineServers onlined servers when master started
    * @throws IOException
    * @throws KeeperException
    * @throws InterruptedException
@@ -426,17 +425,19 @@ public class AssignmentManager extends ZooKeeperListener {
     
     // Run through all regions.  If they are not assigned and not in RIT, then
     // its a clean cluster startup, else its a failover.
-    for (Map.Entry<HRegionInfo, ServerName> e: this.regions.entrySet()) {
-      if (!e.getKey().isMetaTable() && e.getValue() != null) {
-        LOG.debug("Found " + e + " out on cluster");
-        this.failover = true;
-        break;
-      }
-      if (nodes.contains(e.getKey().getEncodedName())) {
-        LOG.debug("Found " + e.getKey().getRegionNameAsString() + " in RITs");
-        // Could be a meta region.
-        this.failover = true;
-        break;
+    synchronized (this.regions) {    
+      for (Map.Entry<HRegionInfo, ServerName> e: this.regions.entrySet()) {
+        if (!e.getKey().isMetaTable() && e.getValue() != null) {
+          LOG.debug("Found " + e + " out on cluster");
+          this.failover = true;
+          break;
+        }
+        if (nodes.contains(e.getKey().getEncodedName())) {
+          LOG.debug("Found " + e.getKey().getRegionNameAsString() + " in RITs");
+          // Could be a meta region.
+          this.failover = true;
+          break;
+        }
       }
     }
 
@@ -2547,8 +2548,6 @@ public class AssignmentManager extends ZooKeeperListener {
    * <p>
    * Returns a map of servers that are not found to be online and the regions
    * they were hosting.
-   * @param onlineServers if one region's location belongs to onlineServers, it
-   *          doesn't need to be assigned.
    * @return map of servers not online to their assigned regions, as stored
    *         in META
    * @throws IOException
@@ -2624,8 +2623,10 @@ public class AssignmentManager extends ZooKeeperListener {
         // add only if region not in disabled and enabling table
         if (false == checkIfRegionBelongsToDisabled(regionInfo)
             && false == checkIfRegionsBelongsToEnabling(regionInfo)) {
-          regions.put(regionInfo, regionLocation);
-          addToServers(regionLocation, regionInfo);
+          synchronized (this.regions) {            
+            regions.put(regionInfo, regionLocation);
+            addToServers(regionLocation, regionInfo);
+          }
         }
         disablingOrEnabling = addTheTablesInPartialState(this.disablingTables,
             this.enablingTables, regionInfo, tableName);
@@ -3366,7 +3367,6 @@ public class AssignmentManager extends ZooKeeperListener {
    * Run through remaining regionservers and unassign all catalog regions.
    */
   void unassignCatalogRegions() {
-    this.servers.entrySet();
     synchronized (this.regions) {
       for (Map.Entry<ServerName, Set<HRegionInfo>> e: this.servers.entrySet()) {
         Set<HRegionInfo> regions = e.getValue();
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
index 09fcd46be9c..0c6b0422487 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
@@ -663,7 +663,6 @@ Server {
   /**
    * Override to change master's splitLogAfterStartup. Used testing
    * @param mfs
-   * @param onlineServers
    */
   protected void splitLogAfterStartup(final MasterFileSystem mfs) {
     mfs.splitLogAfterStartup();
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterFileSystem.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterFileSystem.java
index 368a46fb524..9d177c8a773 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterFileSystem.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterFileSystem.java
@@ -187,8 +187,6 @@ public class MasterFileSystem {
   /**
    * Inspect the log directory to recover any log file without
    * an active region server.
-   * @param onlineServers Set of online servers keyed by
-   * {@link ServerName}
    */
   void splitLogAfterStartup() {
     boolean retrySplitting = !conf.getBoolean("hbase.hlog.split.skip.errors",