From fcc84c258f63bf1f0712f0a62a2ba93d42dbf477 Mon Sep 17 00:00:00 2001
From: Jonathan Gray <jgray@apache.org>
Date: Tue, 25 Aug 2009 22:44:15 +0000
Subject: [PATCH] HBASE-1737  Regions unbalanced when adding new node
 (recommit)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@807846 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                   |  1 +
 .../hadoop/hbase/master/RegionManager.java    | 22 ++++++++++++-------
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 62a5d694a5e..cc1297d739b 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -5,6 +5,7 @@ Release 0.21.0 - Unreleased
   BUG FIXES
    HBASE-1791  Timeout in IndexRecordWriter (Bradford Stephens via Andrew
                Purtell)
+   HBASE-1737  Regions unbalanced when adding new node (recommit)
 
   IMPROVEMENTS
    HBASE-1760  Cleanup TODOs in HTable
diff --git a/src/java/org/apache/hadoop/hbase/master/RegionManager.java b/src/java/org/apache/hadoop/hbase/master/RegionManager.java
index 020136565d6..aee7c88796b 100644
--- a/src/java/org/apache/hadoop/hbase/master/RegionManager.java
+++ b/src/java/org/apache/hadoop/hbase/master/RegionManager.java
@@ -1349,19 +1349,24 @@ class RegionManager implements HConstants {
       double avg = master.serverManager.getAverageLoad();
 
       // nothing to balance if server load not more then average load
-      if (servLoad.getLoad() <= Math.ceil(avg) || avg <= 2.0) return;
+      if(servLoad.getLoad() <= Math.ceil(avg) || avg <= 2.0) {
+        return;
+      }
       
-      // check if server is overloaded
+      // check if current server is overloaded
       int numRegionsToClose = balanceFromOverloaded(servLoad, avg);
       
       // check if we can unload server by low loaded servers
-      if (numRegionsToClose <= 0)
-        balanceToLowloaded(info.getServerName(), servLoad, avg);
+      if(numRegionsToClose <= 0) {
+        numRegionsToClose = balanceToLowloaded(info.getServerName(), servLoad, 
+            avg);
+      }
       
-      if (maxRegToClose > 0)
+      if(maxRegToClose > 0) {
         numRegionsToClose = Math.min(numRegionsToClose, maxRegToClose);
-              
-      if (numRegionsToClose > 0){
+      }
+      
+      if(numRegionsToClose > 0) {
         unassignSomeRegions(info, numRegionsToClose, mostLoadedRegions, 
             returnMsgs);
       }
@@ -1416,7 +1421,8 @@ class RegionManager implements HConstants {
       if (LOG.isDebugEnabled()) {
         LOG.debug("Server " + srvName + " will be unloaded for " +
             "balance. Server load: " + numSrvRegs + " avg: " +
-            avgLoad + ", regions can be moved: " + numMoveToLowLoaded);
+            avgLoad + ", regions can be moved: " + numMoveToLowLoaded +
+            ". Regions to close: " + numRegionsToClose);
       }
       return numRegionsToClose;
     }