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From Anseh Danesh <anseh.dan...@gmail.com>
Subject Re: map phase does not read intermediate results with SequenceFileInputFormat
Date Fri, 25 Oct 2013 16:03:58 GMT
yes.. thanks for the reply..


On Fri, Oct 25, 2013 at 1:46 PM, Dieter De Witte <drdwitte@gmail.com> wrote:

> The question is also on stackoverflow, the problem is that she divides by
> zero in the second mapper I think. (the logs show that both jobs have a
> data flow..
>
>
> 2013/10/25 Robin East <robin.east@xense.co.uk>
>
>> Hi
>>
>> Are you sure job1 created output where you expected it and in the format
>> you expect? Have you tested job2 on its own with some hand-crafted test
>> data? Is the output from job1 consistent with your hand-crafted test data
>> for job2?
>>
>> regards
>> On 25 Oct 2013, at 06:46, Anseh Danesh <anseh.danesh@gmail.com> wrote:
>>
>> Hi all.
>>
>> I have a mapreduce program with two jobs. second job's key and value
>> comes from first job output. but I think the second map does not get the
>> result from first job. in other words I think my second job did not read
>> the output of my first job.. what should I do?
>>
>> here is the code:
>>
>> public class dewpoint extends Configured implements Tool
>> {
>>   private static final Logger logger = LoggerFactory.getLogger(dewpoint.class);
>>
>> static final String KEYSPACE = "weather";
>> static final String COLUMN_FAMILY = "user";
>> private static final String OUTPUT_PATH1 = "/tmp/intermediate1";
>> private static final String OUTPUT_PATH2 = "/tmp/intermediate2";
>> private static final String OUTPUT_PATH3 = "/tmp/intermediate3";
>> private static final String INPUT_PATH1 = "/tmp/intermediate1";
>>
>> public static void main(String[] args) throws Exception
>> {
>>
>>     ToolRunner.run(new Configuration(), new dewpoint(), args);
>>     System.exit(0);
>> }
>>
>> ///////////////////////////////////////////////////////////
>>
>> public static class dpmap1 extends Mapper<Map<String, ByteBuffer>, Map<FloatWritable,
ByteBuffer>, Text, DoubleWritable>
>> {
>>     DoubleWritable val1 = new DoubleWritable();
>>     Text word = new Text();
>>     String date;
>>     float temp;
>>     public void map(Map<String, ByteBuffer> keys, Map<FloatWritable, ByteBuffer>
columns, Context context) throws IOException, InterruptedException
>>     {
>>
>>          for (Entry<String, ByteBuffer> key : keys.entrySet())
>>          {
>>              //System.out.println(key.getKey());
>>              if (!"date".equals(key.getKey()))
>>                  continue;
>>              date = ByteBufferUtil.string(key.getValue());
>>              word.set(date);
>>          }
>>
>>
>>         for (Entry<FloatWritable, ByteBuffer> column : columns.entrySet())
>>         {
>>             if (!"temprature".equals(column.getKey()))
>>                 continue;
>>             temp = ByteBufferUtil.toFloat(column.getValue());
>>             val1.set(temp);
>>             //System.out.println(temp);
>>        }
>>         context.write(word, val1);
>>     }
>> }
>>
>> ///////////////////////////////////////////////////////////
>>
>> public static class dpred1 extends Reducer<Text, DoubleWritable, Text, DoubleWritable>
>> {
>>    public void reduce(Text key, Iterable<DoubleWritable> values, Context context)
throws IOException, InterruptedException
>>     {
>>         double beta = 17.62;
>>         double landa = 243.12;
>>         DoubleWritable result1 = new DoubleWritable();
>>         DoubleWritable result2 = new DoubleWritable();
>>          for (DoubleWritable val : values){
>>          //  System.out.println(val.get());
>>            beta *= val.get();
>>            landa+=val.get();
>>            }
>>          result1.set(beta);
>>          result2.set(landa);
>>
>>          context.write(key, result1);
>>          context.write(key, result2);
>>      }
>> }
>> ///////////////////////////////////////////////////////////
>>
>> public static class dpmap2 extends Mapper <Text, DoubleWritable, Text, DoubleWritable>{
>>
>>     Text key2 = new Text();
>>     double temp1, temp2 =0;
>>
>>     public void map(Text key, Iterable<DoubleWritable> values, Context context)
throws IOException, InterruptedException {
>>         String[] sp = values.toString().split("\t");
>>         for (int i=0; i< sp.length; i+=4)
>>             //key2.set(sp[i]);
>>         System.out.println(sp[i]);
>>             for(int j=1;j< sp.length; j+=4)
>>                 temp1 = Double.valueOf(sp[j]);
>>                 for (int k=3;k< sp.length; k+=4)
>>                     temp2 = Double.valueOf(sp[k]);
>>         context.write(key2, new DoubleWritable(temp2/temp1));
>>
>>     }
>> }
>>
>> ///////////////////////////////////////////////////////////
>>
>>
>> public static class dpred2 extends Reducer<Text, DoubleWritable, Text, DoubleWritable>
>> {
>>    public void reduce(Text key, Iterable<DoubleWritable> values, Context context)
throws IOException, InterruptedException
>>     {
>>
>>        double alpha = 6.112;
>>         double tmp = 0;
>>         DoubleWritable result3 = new DoubleWritable();
>>          for (DoubleWritable val : values){
>>              System.out.println(val.get());
>>              tmp = alpha*(Math.pow(Math.E, val.get()));
>>
>>          }
>>          result3.set(tmp);
>>          context.write(key, result3);
>>
>>
>>   }
>> }
>>
>>
>> ///////////////////////////////////////////////////////////
>>
>>
>> public int run(String[] args) throws Exception
>> {
>>
>>      Job job1 = new Job(getConf(), "DewPoint");
>>      job1.setJarByClass(dewpoint.class);
>>      job1.setMapperClass(dpmap1.class);
>>      job1.setOutputFormatClass(SequenceFileOutputFormat.class);
>>      job1.setCombinerClass(dpred1.class);
>>      job1.setReducerClass(dpred1.class);
>>      job1.setMapOutputKeyClass(Text.class);
>>      job1.setMapOutputValueClass(DoubleWritable.class);
>>      job1.setOutputKeyClass(Text.class);
>>      job1.setOutputValueClass(DoubleWritable.class);
>>      FileOutputFormat.setOutputPath(job1, new Path(OUTPUT_PATH1));
>>
>>
>>      job1.setInputFormatClass(CqlPagingInputFormat.class);
>>
>>      ConfigHelper.setInputRpcPort(job1.getConfiguration(), "9160");
>>      ConfigHelper.setInputInitialAddress(job1.getConfiguration(), "localhost");
>>      ConfigHelper.setInputColumnFamily(job1.getConfiguration(), KEYSPACE, COLUMN_FAMILY);
>>      ConfigHelper.setInputPartitioner(job1.getConfiguration(), "Murmur3Partitioner");
>>
>>      CqlConfigHelper.setInputCQLPageRowSize(job1.getConfiguration(), "3");
>>      job1.waitForCompletion(true);
>>
>>      /***************************************/
>>
>>      if (job1.isSuccessful()){
>>      Job job2 = new Job(getConf(), "DewPoint");
>>      job2.setJarByClass(dewpoint.class);
>>      job2.setMapperClass(dpmap2.class);
>>      job2.setCombinerClass(dpred2.class);
>>      job2.setReducerClass(dpred2.class);
>>      job2.setMapOutputKeyClass(Text.class);
>>      job2.setMapOutputValueClass(DoubleWritable.class);
>>      job2.setOutputKeyClass(Text.class);
>>      job2.setOutputValueClass(DoubleWritable.class);
>>      job2.setOutputFormatClass(TextOutputFormat.class);
>>      job2.setInputFormatClass(SequenceFileInputFormat.class);
>>      FileInputFormat.addInputPath(job2, new Path(OUTPUT_PATH1));
>>      FileOutputFormat.setOutputPath(job2, new Path(OUTPUT_PATH2));
>>      job2.waitForCompletion(true);
>>      }
>>      ///////////////////////////////////////////////////
>>
>>      return 0;
>>   }
>> }
>>
>> for example in my second map phase when I do a System.out.println(key) it does not
print any thing and in reduce result the value is 'infinity'....
>>
>>
>>
>

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