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From Robin East <robin.e...@xense.co.uk>
Subject Re: map phase does not read intermediate results with SequenceFileInputFormat
Date Fri, 25 Oct 2013 10:03:09 GMT
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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