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MapReduce, mail # user - Re: Issue with running hadoop program using eclipse


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Re: Issue with running hadoop program using eclipse
Mohammad Tariq 2013-01-31, 07:10
Hello Vikas,

             It clearly shows that the class can not be found. For
debugging, you can write your MR job as a standalone java program and debug
it. It works. And if you want to just debug your mapper / reducer logic,
you should look into using MRUnit. There is a good
write-up<http://blog.cloudera.com/blog/2009/07/debugging-mapreduce-programs-with-mrunit/>at
Cloudera's blog section which talks about it in detail.

HTH

Warm Regards,
Tariq
https://mtariq.jux.com/
cloudfront.blogspot.com
On Thu, Jan 31, 2013 at 11:56 AM, Vikas Jadhav <[EMAIL PROTECTED]>wrote:

> Hi
> I have one windows machine and one linux machine
> my eclipse is on winowds machine
> and hadoop running on single linux machine
> I am trying to run wordcount program from eclipse(on windows machine) to
> Hadoop(on linux machine)
>  I getting following error
>
>  3/01/31 11:48:14 WARN mapred.JobClient: Use GenericOptionsParser for
> parsing the arguments. Applications should implement Tool for the same.
> 13/01/31 11:48:15 WARN mapred.JobClient: No job jar file set.  User
> classes may not be found. See JobConf(Class) or JobConf#setJar(String).
> 13/01/31 11:48:16 INFO input.FileInputFormat: Total input paths to process
> : 1
> 13/01/31 11:48:16 WARN util.NativeCodeLoader: Unable to load native-hadoop
> library for your platform... using builtin-java classes where applicable
> 13/01/31 11:48:16 WARN snappy.LoadSnappy: Snappy native library not loaded
> 13/01/31 11:48:26 INFO mapred.JobClient: Running job: job_201301300613_0029
> 13/01/31 11:48:27 INFO mapred.JobClient:  map 0% reduce 0%
> 13/01/31 11:48:40 INFO mapred.JobClient: Task Id :
> attempt_201301300613_0029_m_000000_0, Status : FAILED
> java.lang.RuntimeException: java.lang.ClassNotFoundException:
> WordCount$MapClass
>  at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:867)
>  at
> org.apache.hadoop.mapreduce.JobContext.getMapperClass(JobContext.java:199)
>  at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:719)
>  at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
>  at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
>  at java.security.AccessController.doPrivileged(Native Method)
>  at javax.security.auth.Subject.doAs(Subject.java:396)
>  at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
>  at org.apache.hadoop.mapred.Child.main(Child.java:249)
> Caused by: java.lang.ClassNotFoundException: WordCount$MapClass
>  at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
>  at java.security.AccessController.doPrivileged(Native Method)
>  at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
>  at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
>  at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
>  at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
>  at java.lang.Class.forName0(Native Method)
>  at java.lang.Class.forName(Class.java:247)
>  at
> org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:820)
>  at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:865)
>  ... 8 more
>
>
>
>
> Also I want to know how to debug Hadoop Program using eclipse.
>
>
>
>
> Thank You.
>
>