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Hadoop Basic Examples WordCount

开发者 https://www.devze.com 2023-03-28 08:14 出处:网络
I am getting this error with a mostly out of the box configuration from version 0.20.203.0 Where should I look for a potential issue.Most of the configuration is out of the box.I was able to visit th

I am getting this error with a mostly out of the box configuration from version 0.20.203.0

Where should I look for a potential issue. Most of the configuration is out of the box. I was able to visit the local websites for hdfs, task manager.

I am guessing the error is related to a permissions issue on cygwin and windows. Also, googling the problem, they say there might be some kind of out of memory issue. It is such a simple example, I don't see how that could be.

When I try to run the wordcount examples.

$ hadoop jar hadoop-examples-0.20.203.0.jar wordcount /user/hduser/gutenberg /user/hduser/gutenberg-output6

I get this error:

2011-08-12 开发者_StackOverflow中文版15:45:38,299 WARN org.apache.hadoop.mapred.TaskRunner:
attempt_201108121544_0001_m_000008_2 : Child Error
java.io.IOException: Task process exit with nonzero status of 127.
 at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:258)
2011-08-12 15:45:38,878 WARN org.apache.hadoop.mapred.TaskLog: Failed to
retrieve stdout log for task: attempt_201108121544_0001_m_000008_1
java.io.FileNotFoundException:
E:\projects\workspace_mar11\ParseLogCriticalErrors\lib\h\logs\userlogs\j
ob_201108121544_0001\attempt_201108121544_0001_m_000008_1\log.index (The
system cannot find the file specified)
 at java.io.FileInputStream.open(Native Method)
 at java.io.FileInputStream.<init>(FileInputStream.java:106)
 at
org.apache.hadoop.io.SecureIOUtils.openForRead(SecureIOUtils.java:102)
 at
org.apache.hadoop.mapred.TaskLog.getAllLogsFileDetails(TaskLog.java:112)
...

The userlogs/job* directory is empty. Maybe there is some permission issue with those directories.

I am running on windows with cygwin so I don't really know permissions to set.


I couldn't figure out this problem with the current version of hadoop. I reverted from the current version and went to a previous release, hadoop-0.20.2. I had to play around with the core-site.xml configuration file and temp directories but I eventually got the hdfs and map reduce to work properly.

The issue seems to be cygwin, windows and the drive setup that I was using. Hadoop launches a new JVM process when it tries to invoke a 'child' map/reduce task. The actual jvm execute statement is in some shell script.

In my case, hadoop couldn't find the path to the shell script. I am assuming that status code 127 error was the result of the Java Runtime execute not finding the shell script.

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