hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ted Yu <yuzhih...@gmail.com>
Subject Re: [Error]Finding average using hbase hadoop
Date Fri, 16 Aug 2013 13:57:41 GMT
Here is code from Bytes:

  public static float toFloat(byte [] bytes, int offset) {

    return Float.intBitsToFloat(toInt(bytes, offset, SIZEOF_INT));

Looking at your sample data:

 2010-02-04           column=stocks:open, timestamp=1376567559424,
value=*2.5*

The length of value didn't match SIZEOF_INT.

It seems you need to validate the values first.


Cheers


On Fri, Aug 16, 2013 at 3:42 AM, manish dunani <manishd207@gmail.com> wrote:

> hello,
>
> I am using apache hadoop 1.1.2 and hbase 0.94.9 on pseudo distibuted mode.
>
> I am trying to find Average open stocks values.
>
> *sample dataset in hbase::**(table name:nyse4)*
>
>
>  2010-02-04           column=stocks:open, timestamp=1376567559424,
> value=2.5
>  2010-02-04           column=stocks:symbol, timestamp=1376567559424,
> value=QXM
>  2010-02-05           column=stocks:open, timestamp=1376567559429,
> value=2.42
>  2010-02-05           column=stocks:symbol, timestamp=1376567559429,
> value=QXM
>  2010-02-08           column=stocks:open, timestamp=1376567559431,
> value=2.33
>  2010-02-08           column=stocks:symbol, timestamp=1376567559431,
> value=QXM
>
> *code:*(please ignores the lines that are commenting)
>
>
> > package com.maddy;
> >
> > import java.io.IOException;
> >
> > import org.apache.hadoop.conf.Configuration;
> > import org.apache.hadoop.fs.Path;
> > import org.apache.hadoop.hbase.HBaseConfiguration;
> > import org.apache.hadoop.hbase.client.Put;
> > import org.apache.hadoop.hbase.client.Result;
> > import org.apache.hadoop.hbase.client.Scan;
> > import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter;
> > import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
> > import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
> > import org.apache.hadoop.hbase.mapreduce.TableMapper;
> > import org.apache.hadoop.hbase.mapreduce.TableReducer;
> > import org.apache.hadoop.hbase.util.Bytes;
> > //import org.apache.hadoop.io.DoubleWritable;
> > import org.apache.hadoop.io.FloatWritable;
> > import org.apache.hadoop.mapreduce.Job;
> > import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
> >
> >
> > public class openaveragestock
> > {
> >     public static class map extends
> > TableMapper<ImmutableBytesWritable,FloatWritable>
> >     {
> >         @Override
> >
> >         public void map(ImmutableBytesWritable row,Result value,Context
> > context) throws IOException
> >         {
> >
> >             byte[]
> > val=(value.getValue("stocks".getBytes(),"open".getBytes()));
> >             //byte[]
> > val1=(value.getValue("stocks".getBytes(),"symbol".getBytes()));
> >
> >
> >             ImmutableBytesWritable stock_symbol=new
> > ImmutableBytesWritable("symbol".getBytes());
> >
> >
> >             try
> >             {
> >                 context.write(stock_symbol,new
> > FloatWritable(Bytes.toFloat(val)));
> >             }
> >             catch(InterruptedException e)
> >
> >             {
> >                  throw new IOException(e);
> >             }
> >
> >
> >         }
> >
> >
> >     }
> >
> >
> >     public static class reduce extends
> > TableReducer<ImmutableBytesWritable,FloatWritable,ImmutableBytesWritable>
> >     {
> >
> >         @Override
> >         public void reduce(ImmutableBytesWritable
> > key,Iterable<FloatWritable>values,Context context) throws IOException,
> > InterruptedException
> >         {
> >             float sum=0;
> >             int count=0;
> >           //  float average=0;
> >             for(FloatWritable val:values)
> >             {
> >                 sum+=val.get();
> >                 count++;
> >             }
> >             //average=(sum/count);
> >             Put put=new Put(key.get());
> >
> >
> put.add(Bytes.toBytes("stocks_output"),Bytes.toBytes("average"),Bytes.toBytes(sum/count));
> >             System.out.println("For\t"+count+"\t average
> is:"+(sum/count));
> >             context.write(key,put);
> >
> >         }
> >
> >     }
> >
> >     public static void main(String args[]) throws IOException,
> > ClassNotFoundException, InterruptedException
> >     {
> >         Configuration config=HBaseConfiguration.create();
> >         config.addResource("/home/manish/workspace/hbase
> > project/bin/hbase-site.xml");
> >         Job job=new Job(config,"openstockaverage1");
> >
> >
> >         Scan scan=new Scan();
> >         scan.addFamily("stocks".getBytes());
> >         scan.setFilter(new FirstKeyOnlyFilter());
> >
> >         TableMapReduceUtil.initTableMapperJob("nyse4",
> >                 scan,
> >                 map.class,
> >                 ImmutableBytesWritable.class,
> >                 FloatWritable.class,
> >                 job);
> >
> >         TableMapReduceUtil.initTableReducerJob("nyse5",
> >                 reduce.class,
> >                 job);
> >         //job.setReducerClass(reduce.class);
> >
> >         FileOutputFormat.setOutputPath(job, new Path(
> >
> "hdfs://localhost:54310/user/manish/edurekahbasehadoop1"));
> >         job.waitForCompletion(true);
> >     }
> >
> > }
> >
> >
> >
> > *===>Got stuck into error:*
> >
> >
> > 13/08/16 03:21:45 INFO mapred.JobClient: Running job: job_local_0001
> > 13/08/16 03:21:46 INFO mapred.JobClient:  map 0% reduce 0%
> > 13/08/16 03:21:46 INFO mapreduce.TableOutputFormat: Created table
> instance
> > for nyse5
> > 13/08/16 03:21:46 INFO util.ProcessTree: setsid exited with exit code 0
> > 13/08/16 03:21:47 INFO mapred.Task:  Using ResourceCalculatorPlugin :
> > org.apache.hadoop.util.LinuxResourceCalculatorPlugin@50b77c
> > 13/08/16 03:21:47 INFO mapred.MapTask: io.sort.mb = 100
> > 13/08/16 03:21:53 INFO mapred.MapTask: data buffer = 79691776/99614720
> > 13/08/16 03:21:53 INFO mapred.MapTask: record buffer = 262144/327680
> > 13/08/16 03:21:54 WARN mapred.LocalJobRunner: job_local_0001
> > java.lang.IllegalArgumentException: offset (0) + length (4) exceed the
> > capacity of the array: 3
> >     at
> >
> org.apache.hadoop.hbase.util.Bytes.explainWrongLengthOrOffset(Bytes.java:543)
> >     at org.apache.hadoop.hbase.util.Bytes.toInt(Bytes.java:690)
> >     at org.apache.hadoop.hbase.util.Bytes.toFloat(Bytes.java:584)
> >     at org.apache.hadoop.hbase.util.Bytes.toFloat(Bytes.java:574)
> >     at com.maddy.openaveragestock$map.map(openaveragestock.java:41)
> >     at com.maddy.openaveragestock$map.map(openaveragestock.java:1)
> >     at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
> >     at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
> >     at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
> >     at
> > org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:214)
> >
> >
> I cannot find where is it fail??
> Can you please tell me??
> where i was wrong..?
>
>
> Your help will be appreciated.
>
>
>
>
>
>
>
>
>
>
> --
> Regards
>
> *Manish Dunani*
> *Contact No* : +91 9408329137
> *skype id* : manish.dunani*
> *
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message