Question

这让我感到困惑，当我使用wordcount示例时，我将代码保存在master中并让他用slave做事情并且运行良好

但是当我运行我的代码时，它会在奴隶上开始失败，从而产生奇怪的错误，比如

Traceback (most recent call last):
  File "/app/hadoop/tmp/mapred/local/taskTracker/hduser/jobcache/job_201110250901_0005/attempt_201110250901_0005_m_000001_1/work/./mapper.py", line 55, in <module>
    from src.utilities import utilities
ImportError: No module named src.utilities
java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 1
        at org.apache.hadoop.streaming.PipeMapRed.waitOutputThreads(PipeMapRed.java:311)
        at org.apache.hadoop.streaming.PipeMapRed.mapRedFinished(PipeMapRed.java:545)
        at org.apache.hadoop.streaming.PipeMapper.map(PipeMapper.java:121)
        at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:50)
        at org.apache.hadoop.streaming.PipeMapRunner.run(PipeMapRunner.java:36)
        at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:436)
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:372)
        at org.apache.hadoop.mapred.Child$4.run(Child.java:261)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:396)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1059)
        at org.apache.hadoop.mapred.Child.main(Child.java:255)
java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 1
        at org.apache.hadoop.streaming.PipeMapRed.waitOutputThreads(PipeMapRed.java:311)
        at org.apache.hadoop.streaming.PipeMapRed.mapRedFinished(PipeMapRed.java:545)
        at org.apache.hadoop.streaming.PipeMapper.close(PipeMapper.java:132)
        at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:57)
        at org.apache.hadoop.streaming.PipeMapRunner.run(PipeMapRunner.java:36)
        at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:436)
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:372)
        at org.apache.hadoop.mapred.Child$4.run(Child.java:261)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:396)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1059)
        at org.apache.hadoop.mapred.Child.main(Child.java:255)

因为我的路径上没有代码，我做错了吗？

谢谢

Answer 1

使用Hadoop Streaming时，如果目标计算机上没有代码，则必须使用-file标志复制代码/依赖项。确保在Hadoop流命令中指定了map / reduce文件及其依赖项。

$HADOOP_HOME/bin/hadoop  jar $HADOOP_HOME/hadoop-streaming.jar \
    -input myInputDirs \
    -output myOutputDir \
    -mapper myPythonScript.py \
    -reducer /bin/wc \
    -file myPythonScript.py \
    -file myDictionary.txt \

Hadoop集群 - 在运行作业之前，是否需要在所有计算机上复制我的代码？

1 个答案: