hadoop - Hadoop错误停止作业减少流程

Question

我在两节点群集设置上运行了Hadoop作业(例如字数示例)几次，并且到目前为止一直工作良好。我不断收到一个RuntimeException，它将减少过程停滞在19％:

    2013-04-13 18:45:22,191 INFO org.apache.hadoop.mapred.Task: Task:attempt_201304131843_0001_m_000000_0 is done. And is in the process of commiting
    2013-04-13 18:45:22,299 INFO org.apache.hadoop.mapred.Task: Task 'attempt_201304131843_0001_m_000000_0' done.
    2013-04-13 18:45:22,318 INFO org.apache.hadoop.mapred.TaskLogsTruncater: Initializing logs' truncater with mapRetainSize=-1 and reduceRetainSize=-1
    2013-04-13 18:45:23,181 WARN org.apache.hadoop.mapred.Child: Error running child
    java.lang.RuntimeException: Error while running command to get file permissions : org.apache.hadoop.util.Shell$ExitCodeException: 
    at org.apache.hadoop.util.Shell.runCommand(Shell.java:255)
at org.apache.hadoop.util.Shell.run(Shell.java:182)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:375)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:461)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:444)
at org.apache.hadoop.fs.FileUtil.execCommand(FileUtil.java:710)
at org.apache.hadoop.fs.RawLocalFileSystem$RawLocalFileStatus.loadPermissionInfo(RawLocalFileSystem.java:443)
at org.apache.hadoop.fs.RawLocalFileSystem$RawLocalFileStatus.getOwner(RawLocalFileSystem.java:426)
at org.apache.hadoop.mapred.TaskLog.obtainLogDirOwner(TaskLog.java:267)
at org.apache.hadoop.mapred.TaskLogsTruncater.truncateLogs(TaskLogsTruncater.java:124)
at org.apache.hadoop.mapred.Child$4.run(Child.java:260)
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:1149)
at org.apache.hadoop.mapred.Child.main(Child.java:249)

    at org.apache.hadoop.fs.RawLocalFileSystem$RawLocalFileStatus.loadPermissionInfo(RawLocalFileSystem.java:468)
at org.apache.hadoop.fs.RawLocalFileSystem$RawLocalFileStatus.getOwner(RawLocalFileSystem.java:426)
at org.apache.hadoop.mapred.TaskLog.obtainLogDirOwner(TaskLog.java:267)
at org.apache.hadoop.mapred.TaskLogsTruncater.truncateLogs(TaskLogsTruncater.java:124)
at org.apache.hadoop.mapred.Child$4.run(Child.java:260)
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:1149)
at org.apache.hadoop.mapred.Child.main(Child.java:249)

有谁知道这可能是什么原因？

编辑:自己解决。
如果其他任何人遇到相同的问题，则这是由主节点上的etc / hosts文件引起的。我没有输入从属节点的主机名和地址。
这是我的hosts-file在主节点上的结构:

    127.0.0.1   MyUbuntuServer
    192.xxx.x.xx2   master
    192.xxx.x.xx3   MySecondUbuntuServer
    192.xxx.x.xx3   slave

Answer 1

这里描述了类似的问题:
http://comments.gmane.org/gmane.comp.apache.mahout.user/8898

那里的信息可能与hadoop的其他版本有关。它说:

java.lang.RuntimeException: Error while running command to get file permissions : java.io.IOException: Cannot run program "/bin/ls": error=12, Not enough space

他们的解决方案是通过 mapred.child.java.opts * * -Xmx1200M 来更改堆大小

另请参阅: https://groups.google.com/a/cloudera.org/forum/?fromgroups=#!topic/cdh-user/BHGYJDNKMGE

HTH，
阿夫纳