Re: Class not found in mahout split -xm mapreduce

[Marty Kube]

Hi Shengchao,
My understanding is that CDH4 is not supported.  Try CDH3.
Marty
On 01/10/2013 01:03 PM, Shengchao Ding wrote:

I'm running the 20 newsgroups examples on virtual machine of CDH4.1.2.
It ran smoothly but failed if I modify the split command to

mahout split \
     -i newsgroup/vectors \
     --trainingOutput newsgroup/train-vectors \
     --testOutput newsgroup/test-vectors  \
     --randomSelectionPct 40 --overwrite --sequenceFiles -xm mapreduce
-mro newsgroup/mro

The only different to original command is that the method is modified
to mapreduce while the original example is sequential.

I got the following exception.

Error: java.lang.RuntimeException: java.lang.ClassNotFoundException:
Class org.apache.mahout.utils.SplitInputJob$SplitInputMapper not found
         at 
org.apache.hadoop.conf.Configuration.getClass(Configuration.java:1571)
         at 
org.apache.hadoop.mapreduce.task.JobContextImpl.getMapperClass(JobContextImpl.java:186)
         at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:685)
         at org.apache.hadoop.mapred.MapTask.run(MapTask.java:332)
         at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:152)
         at java.security.AccessController.doPrivileged(Native Method)
         at javax.security.auth.Subject.doAs(Subject.java:396)
         at 
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1332)
         at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:147)
Caused by: java.lang.ClassNotFoundException: Class
org.apache.mahout.utils.SplitInputJob$SplitInputMapper not found
         at 
org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:1477)
         at 
org.apache.hadoop.conf.Configuration.getClass(Configuration.java:1569)
         ... 8 more


I checked the mahout package on the distribution as follows.

[cloudera@localhost ~]$ jar tf
/usr/lib/mahout/mahout-examples-0.7-cdh4.1.2-job.jar | grep SplitInput
org/apache/mahout/utils/SplitInputJob$SplitInputReducer.class
org/apache/mahout/utils/SplitInputJob$SplitInputMapper.class
org/apache/mahout/utils/SplitInputJob$SplitInputComparator.class
org/apache/mahout/utils/SplitInputJob.class
org/apache/mahout/utils/SplitInput.class
org/apache/mahout/utils/SplitInput$SplitCallback.class

Can anyone help me out? Thanks.