getting error in oozie job - mapreduce

Question

I have a WordCount MapReduce job, when it runs from hadoop cli it runs well and given the output. but when I run the job through oozie it throwing me error 'Error: java.io.IOException: Type mismatch in key from map: expected org.apache.hadoop.io.Text, received org.apache.hadoop.io.LongWritable'
Here is the code
package Drivers;
import java.io.IOException;
import java.util.StringTokenizer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
public class WordCount extends Configured implements Tool
{
public static void main(String[] args) throws Exception
{
int res = ToolRunner.run(new Configuration(), new WordCount(), args);
System.exit(res);
}
#Override
public int run(String[] args) throws Exception
{
Job job = Job.getInstance(getConf(), "Tool Job");
job.setJarByClass(WordCount.class);
job.setMapperClass(WordMap.class);
job.setReducerClass(RedForSum.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(IntWritable.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(args[0]));
FileOutputFormat.setOutputPath(job, new Path(args[1]));
return job.waitForCompletion(true) ? 0 : 1;
}
//map method
public static class WordMap extends Mapper<LongWritable,Text,Text,IntWritable>
{
public void map(LongWritable k, Text v,Context con) throws IOException, InterruptedException
{
String line=v.toString();
StringTokenizer t = new StringTokenizer(line);
while(t.hasMoreTokens())
{
String word=t.nextToken();
con.write(new Text(word),new IntWritable(1));
}
}
}
//reducer method
public static class RedForSum extends Reducer<Text, IntWritable,Text,IntWritable>
{
public void reduce(Text k, Iterable<IntWritable> vlist, Context con) throws IOException, InterruptedException
{
int tot=0;
for(IntWritable v:vlist)
tot+=v.get();
con.write(k, new IntWritable(tot));
}
}
}
my workflow.xml is here
<workflow-app xmlns="uri:oozie:workflow:0.1" name="map-reduce-wf">
<start to="mr-node"/>
<action name="mr-node">
<map-reduce>
<job-tracker>${jobTracker}</job-tracker>
<name-node>${nameNode}</name-node>
<configuration>
<property>
<name>mapred.mapper.new-api</name>
<value>true</value>
</property>
<property>
<name>mapred.reducer.new-api</name>
<value>true</value>
</property>
<property>
<name>mapred.job.queue.name</name>
<value>${queueName}</value>
</property>
<property>
<name>mapreduce.mapper.class</name>
<value>Drivers.WordCount$WordMap</value>
</property>
<property>
<name>mapreduce.reducer.class</name>
<value>Drivers.WordCount$RedForSum</value>
</property>
<property>
<name>mapred.output.key.class</name>
<value>org.apache.hadoop.io.Text</value>
</property>
<property>
<name>mapred.output.value.class</name>
<value>org.apache.hadoop.io.IntWritable</value>
</property>
<property>
<name>mapred.input.dir</name>
<value>${inputDir}</value>
</property>
<property>
<name>mapred.output.dir</name>
<value>${outputDir}</value>
</property>
</configuration>
</map-reduce>
<ok to="end"/>
<error to="fail"/>
</action>
<kill name="fail">
<message>Map/Reduce failed, error message[${wf:errorMessage(wf:lastErrorNode())}]</message>
</kill>
<end name="end"/>
</workflow-app>
When I run through oozie
oozie job -oozie http://localhost:11000/oozie -config /home/cloudera/job.properties -run
it throwing me the error
Error: java.io.IOException: Type mismatch in key from map: expected org.apache.hadoop.io.Text, received org.apache.hadoop.io.LongWritable
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.collect(MapTask.java:1072)
at org.apache.hadoop.mapred.MapTask$NewOutputCollector.write(MapTask.java:715)
at org.apache.hadoop.mapreduce.task.TaskInputOutputContextImpl.write(TaskInputOutputContextImpl.java:89)
at org.apache.hadoop.mapreduce.lib.map.WrappedMapper$Context.write(WrappedMapper.java:112)
at org.apache.hadoop.mapreduce.Mapper.map(Mapper.java:124)
at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:145)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:787)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:163)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1671)
at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158)
Can someone please let me know where I was mistaken.
Thanks in Advance.

Answer 1

The problem seems to be in workflow xml. here the property name should be mapreduce.map.class and mapreduce.reduce.class instead of mapreduce.mapper.class and mapreduce.reducer.class correspondingly. So modified workflow should have these properties.
<property>
<name>mapreduce.map.class</name>
<value>Drivers.WordCount$WordMap</value>
</property>
<property>
<name>mapreduce.reduce.class</name>
<value>Drivers.WordCount$RedForSum</value>
</property>
For more on this please refere here