[MAHOUT-428] KMeansDriver: No job jar file set leads to ClassNotFoundException: org.apache.mahout.clustering.kmeans.KMeansMapper

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.3
• Fix Version/s: 0.4
• Component/s: classic

Environment

ubuntu 8.10, sun jdk 1.6.0_10-b33, hadoop cluster running 0.20.2+228, build from r957113 of http://svn.apache.org/repos/asf/lucene/mahout/trunk

• Assignee: Ted Dunning
• Reporter: Peter Goldstein
• Created: 23/Jun/10 05:31
• Updated: 31/Jan/24 22:14
• Resolved: 06/Jul/10 17:05

Description

Running the $MAHOUT_HOME/examples/bin/build-reuters.sh script I encountered the following exception:

10/06/23 04:41:00 WARN mapred.JobClient: No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String).
10/06/23 04:41:01 INFO input.FileInputFormat: Total input paths to process : 1
10/06/23 04:41:01 INFO mapred.JobClient: Running job: job_201006222301_0019
10/06/23 04:41:02 INFO mapred.JobClient: map 0% reduce 0%
10/06/23 04:41:11 INFO mapred.JobClient: Task Id : attempt_201006222301_0019_m_000000_0, Status : FAILED
java.lang.RuntimeException: java.lang.ClassNotFoundException: org.apache.mahout.clustering.kmeans.KMeansMapper
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:960)
at org.apache.hadoop.mapreduce.JobContext.getMapperClass(JobContext.java:158)

This appears to be identical in cause to MAHOUT-197 , and has an almost identical fix. Adding a job.setJarByClass(KMeansDriver.class) line to the KMeansDriver.java file fixes the issue.