[HDFS-4558] start balancer failed with NPE

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.2.0
• Fix Version/s: 1.2.0
• Component/s: balancer & mover
• Target Version/s: 1.2.0
• Hadoop Flags: Reviewed
• Assignee: Junping Du
• Reporter: Wenwu Peng
• Created: 06/Mar/13 11:10
• Updated: 15/May/13 05:16
• Resolved: 08/Mar/13 03:42

Description

start balancer failed with NPE
File this issue to track for QE and dev take a look

balancer.log:
2013-03-06 00:19:55,174 ERROR org.apache.hadoop.hdfs.server.balancer.Balancer: java.lang.NullPointerException
at org.apache.hadoop.hdfs.server.namenode.BlockPlacementPolicy.getInstance(BlockPlacementPolicy.java:165)
at org.apache.hadoop.hdfs.server.balancer.Balancer.checkReplicationPolicyCompatibility(Balancer.java:799)
at org.apache.hadoop.hdfs.server.balancer.Balancer.<init>(Balancer.java:808)
at org.apache.hadoop.hdfs.server.balancer.Balancer.main(Balancer.java:831)

Balancer.java
private void checkReplicationPolicyCompatibility(Configuration conf)
throws UnsupportedActionException

{ if (!(BlockPlacementPolicy.getInstance(conf, null, null) <== here instanceof BlockPlacementPolicyDefault)) { throw new UnsupportedActionException( "Balancer without BlockPlacementPolicyDefault"); }

}