FileSystem close Exception

1.오늘 mr를 쓸 때 맵이 완성된 후 오랫동안 Reducer를 실행하지 않았고 오류도 보고하지 않았으며 미션 실패만 알렸습니다...
해결 방안:jobtracker의 로그에서 오류 정보 (hadoop-hadoop-jobtracker-steven.log) 를 보십시오.

2014-05-09 17:42:46,811 ERROR org.apache.hadoop.hdfs.DFSClient: Failed to close file /ies/result/_logs/history/job_201405091001_0005_1399626116239_hadoop_IES%5FResult%5F2014-05-09+17%3A01%3A55
org.apache.hadoop.ipc.RemoteException: org.apache.hadoop.hdfs.server.namenode.LeaseExpiredException: No lease on /ies/result/_logs/history/job_201405091001_0005_1399626116239_hadoop_IES%5FResult%5F2014-05-09+17%3A01%3A55 File does not exist. Holder DFSClient_NONMAPREDUCE_1956983432_28 does not have any open files
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:1999)
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkLease(FSNamesystem.java:1990)
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:1899)
        at org.apache.hadoop.hdfs.server.namenode.NameNode.addBlock(NameNode.java:783)
        at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:587)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1432)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1428)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:415)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1190)
        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1426)

        at org.apache.hadoop.ipc.Client.call(Client.java:1113)
        at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:229)
        at com.sun.proxy.$Proxy7.addBlock(Unknown Source)
        at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:85)
        at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:62)
        at com.sun.proxy.$Proxy7.addBlock(Unknown Source)
        at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.locateFollowingBlock(DFSClient.java:3720)
        at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:3580)
        at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2600(DFSClient.java:2783)
        at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:3023)
2014-05-09 17:42:46,816 INFO org.apache.hadoop.mapred.JobTracker: Removing task 'attempt_201405091001_0005_m_000001_0'
2014-05-09 17:42:46,816 INFO org.apache.hadoop.mapred.JobTracker: Removing task 'attempt_201405091001_0005_m_000002_0'
2014-05-09 17:42:46,824 INFO org.apache.hadoop.mapred.JobHistory: Moving file:/home/hadoop/hadoop1.1.2/hadoop-1.2.1/logs/history/job_201405091001_0005_conf.xml to file:/home/hadoop/hadoop1.1.2/hadoop-1.2.1/logs/history/done/version-1/localhost_1399600913639_/2014/05/09/000000
2014-05-09 17:46:02,621 INFO org.apache.hadoop.mapred.TaskInProgress: Error from attempt_201405091001_0006_m_000000_2: Task attempt_201405091001_0006_m_000000_2 failed to report status for 600 seconds. Killing!
2014-05-09 17:46:02,621 INFO org.apache.hadoop.mapred.JobTracker: Removing task 'attempt_201405091001_0006_m_000000_2'
2014-05-09 17:46:02,622 INFO org.apache.hadoop.mapred.JobTracker: Adding task (TASK_CLEANUP) 'attempt_201405091001_0006_m_000000_2' to tip task_201405091001_0006_m_000000, for tracker 'tracker_steven:localhost/127.0.0.1:37363'
2014-05-09 17:46:05,041 INFO org.apache.hadoop.mapred.JobInProgress: Choosing a failed task task_201405091001_0006_m_000000
2014-05-09 17:46:05,042 INFO org.apache.hadoop.mapred.JobTracker: Adding task (MAP) 'attempt_201405091001_0006_m_000000_3' to tip task_201405091001_0006_m_000000, for tracker 'tracker_steven:localhost/127.0.0.1:37363'
2014-05-09 17:46:05,042 INFO org.apache.hadoop.mapred.JobTracker: Removing task 'attempt_201405091001_0006_m_000000_2'

오류 원인: 파일을 닫는 데 실패했습니다. 바로 File System의 일입니다. mr 코드를 보니 파일을 닫을 곳이 없군요. 무슨 상황!!! 
인터넷에서 이런 글을 찾았습니다. 주로 맵에서 파일을 닫았으면, 맵이 실행된 후cleanup를 호출하여 파일을 닫을 때 프로그램이 오류가 발생할 수 있습니다.

Generally, you should not call fs.close() when you do a FileSystem.get(...). FileSystem.get(...) won't actually open a "new" FileSystem object. When you do a close() on that FileSystem, you will close it for any upstream process as well.

For example, if you close the FileSystem during a mapper, your MapReduce driver will fail when it again tries to close the FileSystem on cleanup.

그런데 문제는 맵에서cleanup 함수를 실행할 때 Filesystem을 닫지 않았다는 거예요!!!코드를 자세히 살펴보니 setup에서 호출되었습니다:super.setup(context);설마 여기서 파일 흐름이 꺼진 거야?그래서 이 코드를 삭제했습니다. 프로그램이 정상입니다...나 이상해...
참조:http://stackoverflow.com/questions/20492278/hdfs-filesystem-close-exception