MapR 5.0 Documentation : Configuring Existing MapReduce v1 Jobs to Run in MapR 4.0.x

If you have existing MapReduce v1 jobs from a hadoop 1.x cluster that you want to run in the 4.0.x cluster, you may need to recompile the MapReduce jobs. 

If your MapReduce v1 job contains the following API, you may need to recompile the job prior to running the job in the 4.0.x cluster:

MapReduce Job APISource CompatibilityBinary CompatibilityRecompile Required?
org.apache.hadoop.mapredYesPartialIf Job, JobControl, or JobContext classes are used, then the code requires minor updates and a recompile due to API changes.

org.apache.hadoop.mapreduceYesNoRecompilation is required.

To recompile a MapReduce v1 job:

Run the following command: javac -cp $(/opt/mapr/hadoop/hadoop-0.20.2/bin/hadoop classpath) <java.program>