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Registered: ‎08-17-2016

Reducer Output has floating point overflow. how can i resolve this

Sales Driver Class

package
mr.map; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.FloatWritable; //import org.apache.hadoop.mapreduce.Mapper; //import org.apache.hadoop.mapreduce.Reducer; public class SalesDriver { public static void main(String args[]) throws Exception { Configuration c=new Configuration(); Job j=new Job(c,"Sales"); j.setJarByClass(SalesDriver.class); j.setMapperClass(SalesMapper.class); j.setReducerClass(SalesReducer.class); //j.setNumReduceTasks(0); j.setOutputKeyClass(Text.class); j.setOutputValueClass(FloatWritable.class); Path in=new Path(args[0]); Path out=new Path(args[1]); FileInputFormat.addInputPath(j, in); FileOutputFormat.setOutputPath(j, out); System.exit(j.waitForCompletion(true)?0:1); } }

Sales Mapper Class

package mr.map;

import java.io.IOException;

//import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.FloatWritable;
import org.apache.hadoop.io.LongWritable;
//import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

public class SalesMapper extends Mapper<LongWritable, Text, Text, FloatWritable>
{
    public void map(LongWritable k, Text v, Context con) throws IOException, InterruptedException
    {
        String w[]=v.toString().split(" ");
        String product=w[3];
        //String store=w[2];
        //float cost=Integer.parseInt(w[4]);
        float costx = Float.parseFloat(w[4]);

        //String newline= product+","+store; //","+costx;
        //String newline = product;        con.write(new Text(product), new FloatWritable(costx));
    }
}

Sales Reducer Class

package mr.map;

import java.io.IOException;

import org.apache.hadoop.io.FloatWritable;
//import org.apache.hadoop.io.IntWritable;
//import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

public class SalesReducer extends Reducer<Text, FloatWritable, Text, FloatWritable>
{
    public void reduce(Text k, Iterable<FloatWritable>vlist, Context con) throws IOException, InterruptedException
    {
        int tot=0;
        for (FloatWritable v:vlist)
        {            tot += v.get();
        }
        //int total= (int)tot;        con.write(new Text(k), new FloatWritable(tot));
    }
}

Result of the MapReduce

Result of the MapReduce

I am not able to understand why all the result is coming out in a large floating point number and all around the number 5.7480884E7.

Below is the example of input to the mapreduce program:

  2012-01-01 09:00 San Jose Men's Clothing 214.05 Amex              
  2012-01-01 09:00 Fort Worth Women's Clothing 153.57 Visa          
  2012-01-01 09:00 San Diego Music 66.08 Cash                       
  2012-01-01 09:00 Pittsburgh Pet Supplies 493.51 Discover          
  2012-01-01 09:00 Omaha Children's Clothing 235.63 MasterCard      
  2012-01-01 09:00 Stockton Men's Clothing 247.18 MasterCard        
  2012-01-01 09:00 Austin Cameras 379.6 Visa                        
  2012-01-01 09:00 New York Consumer Electronics 296.8 Cash         
  2012-01-01 09:00 Corpus Christi Toys 25.38 Discover               
  2012-01-01 09:00 Fort Worth Toys 213.88 Visa                      
  2012-01-01 09:00 Las Vegas Video Games 53.26 Visa                 
  2012-01-01 09:00 Newark Video Games 39.75 Cash                    
  2012-01-01 09:00 Austin Cameras 469.63 MasterCard                 
  2012-01-01 09:00 Greensboro DVDs 290.82 MasterCard                
  2012-01-01 09:00 San Francisco Music 260.65 Discover              
  2012-01-01 09:00 Lincoln Garden 136.9 Visa                        
  2012-01-01 09:00 Buffalo Women's Clothing 483.82 Visa             
  2012-01-01 09:00 San Jose Women's Clothing 215.82 Cash            
  2012-01-01 09:00 Boston Cameras 418.94 Amex                       
  2012-01-01 09:00 Houston Baby 309.16 Visa                         
  2012-01-01 09:00 Las Vegas Books 93.39 Visa                       
  2012-01-01 09:00 Virginia Beach Children's Clothing 376.11 Amex   
  2012-01-01 09:01 Riverside Consumer Electronics 252.88 Cash       
  2012-01-01 09:01 Tulsa Baby 205.06 Visa                           
  2012-01-01 09:01 Reno Crafts 88.25 Visa                           
  2012-01-01 09:01 Chicago Books 31.08 Cash                         
  2012-01-01 09:01 Fort Wayne Men's Clothing 370.55 Amex            
  2012-01-01 09:01 San Bernardino Consumer Electronics 170.2 Cash   
  2012-01-01 09:01 Madison Men's Clothing 16.78 Visa                
  2012-01-01 09:01 Austin Sporting Goods 327.75 Discover            
  2012-01-01 09:01 Portland CDs 108.69 Amex                         
  2012-01-01 09:01 Riverside Sporting Goods 15.41 Discover          
  2012-01-01 09:01 Reno Toys 80.46 Visa                             
  2012-01-01 09:01 Anchorage Music 298.86 MasterCard    


 

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