diff --git a/.gitignore b/.gitignore
index 845a2ddc007..c952bc075ac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ examples/rand/RealtimeNode.out
 examples/twitter/RealtimeNode.out
 *.log
 *.DS_Store
+server/src/main/resources/static/js/SlickGrid-master/
\ No newline at end of file
diff --git a/server/src/main/java/com/metamx/druid/master/BalancerStrategy.java b/server/src/main/java/com/metamx/druid/master/BalancerStrategy.java
index 9430f22bbc1..7f3b857820e 100644
--- a/server/src/main/java/com/metamx/druid/master/BalancerStrategy.java
+++ b/server/src/main/java/com/metamx/druid/master/BalancerStrategy.java
@@ -25,7 +25,7 @@ import java.util.List;
 
 public interface BalancerStrategy
 {
-  public ServerHolder findNewSegmentHome(final DataSegment proposalSegment,final Iterable<ServerHolder> serverHolders);
+  public ServerHolder findNewSegmentHome(final DataSegment proposalSegment,final List<ServerHolder> serverHolders);
   public BalancerSegmentHolder pickSegmentToMove(final List<ServerHolder> serverHolders);
   public void emitStats(String tier, MasterStats stats, List<ServerHolder> serverHolderList);
 }
diff --git a/server/src/main/java/com/metamx/druid/master/CostBalancerStrategy.java b/server/src/main/java/com/metamx/druid/master/CostBalancerStrategy.java
index b841324da73..feacd374c44 100644
--- a/server/src/main/java/com/metamx/druid/master/CostBalancerStrategy.java
+++ b/server/src/main/java/com/metamx/druid/master/CostBalancerStrategy.java
@@ -44,7 +44,7 @@ public class CostBalancerStrategy implements BalancerStrategy
 
   @Override
   public ServerHolder findNewSegmentHome(
-      DataSegment proposalSegment, Iterable<ServerHolder> serverHolders
+      DataSegment proposalSegment, List<ServerHolder> serverHolders
   )
   {
     return computeCosts(proposalSegment, serverHolders).rhs;
diff --git a/server/src/main/java/com/metamx/druid/master/DruidMasterBalancer.java b/server/src/main/java/com/metamx/druid/master/DruidMasterBalancer.java
index 2c765e8f23d..cc8dd39eac2 100644
--- a/server/src/main/java/com/metamx/druid/master/DruidMasterBalancer.java
+++ b/server/src/main/java/com/metamx/druid/master/DruidMasterBalancer.java
@@ -115,7 +115,7 @@ public class DruidMasterBalancer implements DruidMasterHelper
       for (int iter = 0; iter < maxSegmentsToMove; iter++) {
         final BalancerSegmentHolder segmentToMove = strategy.pickSegmentToMove(serverHolderList);
 
-        if (params.getAvailableSegments().contains(segmentToMove.getSegment())) {
+        if (segmentToMove!=null && params.getAvailableSegments().contains(segmentToMove.getSegment())) {
           final ServerHolder holder = strategy.findNewSegmentHome(segmentToMove.getSegment(), serverHolderList);
 
           if (holder != null) {
diff --git a/server/src/main/java/com/metamx/druid/master/RandomBalancerStrategy.java b/server/src/main/java/com/metamx/druid/master/RandomBalancerStrategy.java
index 279eab46008..b1cff01d782 100644
--- a/server/src/main/java/com/metamx/druid/master/RandomBalancerStrategy.java
+++ b/server/src/main/java/com/metamx/druid/master/RandomBalancerStrategy.java
@@ -19,10 +19,8 @@
 
 package com.metamx.druid.master;
 
-import com.google.common.collect.Lists;
 import com.metamx.druid.client.DataSegment;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
 
@@ -32,11 +30,10 @@ public class RandomBalancerStrategy implements BalancerStrategy
 
   @Override
   public ServerHolder findNewSegmentHome(
-      DataSegment proposalSegment, Iterable<ServerHolder> serverHolders
+      DataSegment proposalSegment, List<ServerHolder> serverHolders
   )
   {
-    ArrayList<ServerHolder> serverHoldersList = Lists.newArrayList(serverHolders);
-    return serverHoldersList.get(new Random().nextInt(serverHoldersList.size()));
+    return serverHolders.get(new Random().nextInt(serverHolders.size()));
   }
 
   @Override
diff --git a/server/src/main/java/com/metamx/druid/master/ReservoirSegmentSampler.java b/server/src/main/java/com/metamx/druid/master/ReservoirSegmentSampler.java
index 8ac2d949d5a..17c4b38f94a 100644
--- a/server/src/main/java/com/metamx/druid/master/ReservoirSegmentSampler.java
+++ b/server/src/main/java/com/metamx/druid/master/ReservoirSegmentSampler.java
@@ -45,6 +45,12 @@ public class ReservoirSegmentSampler
         numSoFar++;
       }
     }
-    return new BalancerSegmentHolder(fromServerHolder.getServer(), proposalSegment);
+    if (fromServerHolder!=null)
+    {
+      return new BalancerSegmentHolder(fromServerHolder.getServer(), proposalSegment);
+    }
+    else{
+      return null;
+    }
   }
 }