[BIGTOP-1470] Mahout 0.9 couldn't work with hadoop 2.x

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Won't Fix
• Affects Version/s: 0.8.0
• Fix Version/s: 0.8.0
• Component/s: build
• Assignee: Unassigned
• Reporter: Hu Liu,
• Created: 28/Sep/14 10:16
• Updated: 02/Oct/14 23:53
• Resolved: 02/Oct/14 23:53

Description

I built Mahout 0.9 with Bigtop and found it couldn't work with hadoop 2.x.

Exception in thread "main" java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.JobContext, but class was expected
    at org.apache.mahout.common.HadoopUtil.getCustomJobName(HadoopUtil.java:174)
    at org.apache.mahout.common.AbstractJob.prepareJob(AbstractJob.java:614)
    at org.apache.mahout.cf.taste.hadoop.preparation.PreparePreferenceMatrixJob.run(PreparePreferenceMatrixJob.java:73)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
    at org.apache.mahout.cf.taste.hadoop.item.RecommenderJob.run(RecommenderJob.java:164)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
    at org.apache.mahout.cf.taste.hadoop.item.RecommenderJob.main(RecommenderJob.java:322)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:72)
    at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:144)
    at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:152)
    at org.apache.mahout.driver.MahoutDriver.main(MahoutDriver.java:195)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:212)

The root cause is that bigtop uses the wrong parameter hadoop2.version when building Mahout.

mvn clean install -Dmahout.skip.distribution=false -DskipTests -Dhadoop2.version=$HADOOP_VERSION "$@"

For Mahout 0.9 , the correct property is hadoop.version in pom.xml of Mahout 0.9

<hadoop.version>1.2.1</hadoop.version>

Issue Links

• is related to: MAHOUT-1329 Mahout for hadoop 2
• relates to: MAHOUT-1329 Mahout for hadoop 2

Sub-Tasks

• 0.8 RC: Looks like it is building Mahout1x ?: Resolved