[HDFS-3471] NullPointerException when NameNode is closing

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.0.0
• Component/s: namenode
• Labels: NameNode NullPointerException,
• Tags: namenode, NPE
• Assignee: Unassigned
• Reporter: Denny Ye
• Created: 28/May/12 09:32
• Updated: 28/May/12 09:32

Description

In local environment, there is NPE when NameNode is closing.
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2012-05-28 08:54:33,139 INFO org.apache.hadoop.ipc.Server: IPC Server handler 7 on 9000, call blockReceived(DatanodeRegistration(xx.xxx.xxx.xxx:50010, storageID=DS-1391415252-xx.xxx.xxx.xxx-50010-1330957852052, infoPort=50075, ipcPort=50020), [Lorg.apache.hadoop.hdfs.protocol.Block;@6639be68, [Ljava.lang.String;@5903d246) from xx.xxx.xxx.xxx:17022: error: java.io.IOException: java.lang.NullPointerException
java.io.IOException: java.lang.NullPointerException
at org.apache.hadoop.hdfs.server.namenode.BlocksMap.getStoredBlock(BlocksMap.java:408)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.addStoredBlock(FSNamesystem.java:3313)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.blockReceived(FSNamesystem.java:3870)
at org.apache.hadoop.hdfs.server.namenode.NameNode.blockReceived(NameNode.java:962)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:557)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1434)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1430)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1127)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1428)

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I tracked the source code. It may be caused by the FSNameSystem closed early than RPC server. The BlockMap instance is null for coming request from DN.