Namenode constantly using up 100% CPU --------------------------------------
Key: HADOOP-751 URL: http://issues.apache.org/jira/browse/HADOOP-751 Project: Hadoop Issue Type: Bug Components: dfs Affects Versions: 0.8.0 Reporter: Koji Noguchi Trying to figure out the exact cause, but CPU load of the namenode is constantly 100% without any file exchanges. .log file of the namenode showing the following exception about every 20 seconds. 2006-11-27 16:02:07,199 INFO org.apache.hadoop.ipc.Server: IPC Server handler 5 on 8020 call error: java.io.IOException: java.util.NoSuchElementException java.io.IOException: java.util.NoSuchElementException at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1029) at java.util.TreeMap$KeyIterator.next(TreeMap.java:1058) at java.util.AbstractCollection.toArray(AbstractCollection.java:176) at org.apache.hadoop.dfs.DatanodeDescriptor.getBlocks(DatanodeDescriptor.java:96) at org.apache.hadoop.dfs.FSNamesystem.processReport(FSNamesystem.java:1446) at org.apache.hadoop.dfs.NameNode.blockReport(NameNode.java:506) at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:387) at org.apache.hadoop.ipc.Server$Handler.run(Server.java:518) On some of the datanodes, .log file is showing 2006-11-27 16:03:57,542 WARN org.apache.hadoop.dfs.DataNode: org.apache.hadoop.ipc.RemoteException: java.io.IOException: java.util.NoSuchElementException at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1029) at java.util.TreeMap$KeyIterator.next(TreeMap.java:1058) at java.util.AbstractCollection.toArray(AbstractCollection.java:176) at org.apache.hadoop.dfs.DatanodeDescriptor.getBlocks(DatanodeDescriptor.java:96) at org.apache.hadoop.dfs.FSNamesystem.processReport(FSNamesystem.java:1446) at org.apache.hadoop.dfs.NameNode.blockReport(NameNode.java:506) at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:387) at org.apache.hadoop.ipc.Server$Handler.run(Server.java:518) at org.apache.hadoop.ipc.Client$Connection.run(Client.java:248) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira