我在Mapreduce作业中获得org.apache.hadoop.ipc.RemoteException:java.io.IOException？

我使用以下几点安装了hadoop

使用tar文件安装hadoop

创建hdfs用户和组并将其分配到hadoop文件夹

然后在/opt文件夹中为namenode和datanode创建hdfs目录

还设置了配置文件 但是当我试图运行hadoop-jar-hadoop-examples-1.0.0.jar pi 4 100时，我遇到了这个错误

2014-11-05 12:12:02,978 WARN org.apache.hadoop.hdfs.DFSClient: Error Recovery for block null bad datanode[0] nodes == null 
2014-11-05 12:12:02,978 WARN org.apache.hadoop.hdfs.DFSClient: Could not get block locations. Source file "/tmp/hadoop-hdfs/mapred/system/jobtracker.info" - Aborting...
2014-11-05 12:12:02,979 WARN org.apache.hadoop.mapred.JobTracker: Writing to file   hdfs://hostname:9000/tmp/hadoop-hdfs/mapred/system/jobtracker.info failed! 
2014-11-05 12:12:02,979 WARN org.apache.hadoop.mapred.JobTracker: FileSystem is not ready yet!
2014-11-05 12:12:02,982 WARN org.apache.hadoop.mapred.JobTracker: Failed to initialize recovery manager.

org.apache.hadoop.ipc.RemoteException: java.io.IOException: File /tmp/hadoop-hdfs/mapred/system/jobtracker.info could only be replicated to 0 nodes, instead of 1
     at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:1556)
     at org.apache.hadoop.hdfs.server.namenode.NameNode.addBlock(NameNode.java:696)
     at sun.reflect.GeneratedMethodAccessor7.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$Server.call(RPC.java:563)
     at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1388)
     at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1384)
     at java.security.AccessController.doPrivileged(Native Method)
     at javax.security.auth.Subject.doAs(Subject.java:415)
     at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1083)
     at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1382)

     at org.apache.hadoop.ipc.Client.call(Client.java:1066)
     at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:225)
     at com.sun.proxy.$Proxy5.addBlock(Unknown Source)
     at sun.reflect.GeneratedMethodAccessor6.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:82)
     at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:59)
     at com.sun.proxy.$Proxy5.addBlock(Unknown Source)
     at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.locateFollowingBlock(DFSClient.java:3507)
     at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:3370)
     at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2700(DFSClient.java:2586)
     at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:2826)

这里我想提到的一件事是，我已经将hdfs路径设置为

/mnt

direcotry，但hdfs仍然指向

/tmp/hadoop hdfs

请给出一些建议

检查您尝试运行的操作节点的所有路径，这通常是由于提供了错误的输入/输出路径造成的

另外，如果要重新运行工作流作业，请确保coordinator.xml（或job.xml）中提供的所有事件和属性都必须存在于job.properties中，因为与正常协调器作业运行（计划运行）相比，重新运行工作流作业不会引用job.xml

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你格式化你的名字节点了吗？检查是否已启动所有DataNode是的，我已格式化namenode。我删除了/tmp/hadoop hdfs/dfs/data和/tmp/hadoop hdfs/dfs/name目录的内容。同样的错误再次出现。我想知道为什么hadoop hdfs在/tmp目录中指向或存储数据，如果我将配置设置为/mnt direcorylooks，就像datanode有问题一样。可以检查所有datanode是否正常运行。是的datanode正在运行我可以在jps命令后看到它，并且我可以执行此命令hadoop fs-ls/successfully检查您的datanode（端口）是否阻塞namenode。