昨晚突然之间mr跑步起来了
jps查看 进程都在的，但是在reduce任务跑了85%的时候会抛异常
异常情况如下：
2016-09-21 21:32:28,538 INFO [org.apache.hadoop.mapreduce.Job] - map 100% reduce 84%
2016-09-21 21:32:30,623 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:33,626 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:36,627 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:39,628 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:42,630 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:45,632 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:48,634 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:51,634 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:54,636 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:32:57,638 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:00,639 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:03,641 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:04,554 INFO [org.apache.hadoop.mapreduce.Job] - map 100% reduce 85%
2016-09-21 21:33:06,643 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:09,644 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:12,645 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:15,648 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:18,650 INFO [org.apache.hadoop.mapred.LocalJobRunner] - reduce > reduce
2016-09-21 21:33:19,268 WARN [org.apache.hadoop.hdfs.DFSClient] - DataStreamer Exception
org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /anagram/out/_temporary/0/_temporary/attempt_local946954997_0001_r_000000_0/part-r-00000
could only be replicated to 0 nodes instead of minReplication (=1). There are 1 datanode(s) running and no node(s) are excluded in this operation.
at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget(BlockManager.java:1384)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:2477)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:555)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:387)
at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java:59582)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2048)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2044)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2042) at org.apache.hadoop.ipc.Client.call(Client.java:1347)
at org.apache.hadoop.ipc.Client.call(Client.java:1300)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)
at com.sun.proxy.$Proxy9.addBlock(Unknown Source)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:186)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy9.addBlock(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.addBlock(ClientNamenodeProtocolTranslatorPB.java:330)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.locateFollowingBlock(DFSOutputStream.java:1226)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1078)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:514)
2016-09-21 21:33:19,330 WARN [org.apache.hadoop.mapred.LocalJobRunner] - job_local946954997_0001
org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /anagram/out/_temporary/0/_temporary/attempt_local946954997_0001_r_000000_0/part-r-00000 could only be replicated to 0 nodes instead of minReplication (=1). There are 1 datanode(s) running and no node(s) are excluded in this operation.
at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.chooseTarget(BlockManager.java:1384)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:2477)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.addBlock(NameNodeRpcServer.java:555)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.addBlock(ClientNamenodeProtocolServerSideTranslatorPB.java:387)
at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java:59582)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2048)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2044)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2042) at org.apache.hadoop.ipc.Client.call(Client.java:1347)
at org.apache.hadoop.ipc.Client.call(Client.java:1300)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)
at com.sun.proxy.$Proxy9.addBlock(Unknown Source)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:186)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy9.addBlock(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.addBlock(ClientNamenodeProtocolTranslatorPB.java:330)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.locateFollowingBlock(DFSOutputStream.java:1226)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(DFSOutputStream.java:1078)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:514)
2016-09-21 21:33:19,560 INFO [org.apache.hadoop.mapreduce.Job] - Job job_local946954997_0001 failed with state F
看到这里以为是副本问题
could only be replicated to 0 nodes instead of minReplication (=1).
随后把副本改为三个还是出现此异常。然后把集群从启一下发现datanode没有能够启动
后面查看日志发现datanode启动异常
java.io.IOException: Incompatible clusterIDs in /data/dfs/data: namenode clusterID = CID-70f4fcbc-13a2-4918-a90a-5a7b4b47baa8; datanode clusterID = CID-be72a034-047f-4d49-bb40-dd411b8007e6
at org.apache.hadoop.hdfs.server.datanode.DataStorage.doTransition(DataStorage.java:391)
at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:191)
at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:219)
at org.apache.hadoop.hdfs.server.datanode.DataNode.initStorage(DataNode.java:837)
at org.apache.hadoop.hdfs.server.datanode.DataNode.initBlockPool(DataNode.java:808)
at org.apache.hadoop.hdfs.server.datanode.BPOfferService.verifyAndSetNamespaceInfo(BPOfferService.java:280)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.connectToNNAndHandshake(BPServiceActor.java:222)
at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:664)
at java.lang.Thread.run(Thread.java:745)
2016-09-21 15:57:22,786 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Ending block pool service for: Block pool BP-1394444749-192.168.19.130-1474417014093 (storage id DS-433243534-192.168.19.130-50010-1473626296058) service to selfimpr/192.168.19.130:9000
2016-09-21 15:57:22,938 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Removed Block pool BP-1394444749-192.168.19.130-1474417014093 (storage id DS-433243534-192.168.19.130-50010-1473626296058)
2016-09-21 15:57:24,939 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Exiting Datanode
2016-09-21 15:57:24,940 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 0
随后手动把namenode和datanode 的clusterID 统一了，后面集群启动成功，但是程序异常依旧，最后把namenode和datanode统一格式化，程序正常运行。
参考：
http://*.com/questions/15571584/writing-to-hdfs-could-only-be-replicated-to-0-nodes-instead-of-minreplication
https://issues.apache.org/jira/browse/HDFS-107