Index: hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java =================================================================== --- hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java (revision 1469379) +++ hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/BaseLoadBalancer.java (working copy) @@ -140,9 +140,11 @@ if (regionFinder != null) { //region location List loc = regionFinder.getTopBlockLocations(region); - regionLocations[regionIndex] = new int[loc.size()]; - for (int i=0; i < loc.size(); i++) { - regionLocations[regionIndex][i] = serversToIndex.get(loc.get(i)); + if (loc.size() > 0) { + regionLocations[regionIndex] = new int[loc.size()]; + for (int i=0; i < loc.size(); i++) { + regionLocations[regionIndex][i] = serversToIndex.get(loc.get(i)); + } } }