hadoop-hdfs-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Kartashov, Andy" <Andy.Kartas...@mpac.ca>
Subject RE: Trouble with Word Count example
Date Thu, 29 Nov 2012 19:13:52 GMT
Can you try running jar -tvf word_cnt.jar and see if your static nested classes WordCount2$Map.class
and WordCount2$Reduce.class have actually been added to the jar.


From: Sandeep Jangra [mailto:sandeepjangra@gmail.com]
Sent: Thursday, November 29, 2012 1:36 PM
To: user@hadoop.apache.org
Subject: Re: Trouble with Word Count example

Also, I did set the HADOOP_CLASSPATH variable to point to the word_cnt.jar only.

On Thu, Nov 29, 2012 at 10:54 AM, Sandeep Jangra <sandeepjangra@gmail.com<mailto:sandeepjangra@gmail.com>>
Thanks for the quick response Mahesh.

I am using the following command:

sudo -u hdfs hadoop jar word_cnt.jar WordCount2  /tmp/root/input /tmp/root/output15  -libjars=word_cnt.jar
(The input directory exists on the hdfs)

This is how I compiled and packaged it:

javac -classpath /usr/lib/hadoop-0.20-mapreduce/hadoop-core.jar:/usr/lib/hadoop/*  -d word_cnt
jar -cvf word_cnt.jar -C word_cnt/ .

On Thu, Nov 29, 2012 at 10:46 AM, Mahesh Balija <balijamahesh.mca@gmail.com<mailto:balijamahesh.mca@gmail.com>>
Hi Sandeep,

           For me everything seems to be alright.
           Can you tell us how are you running this job?

Calsoft Labs.
On Thu, Nov 29, 2012 at 9:01 PM, Sandeep Jangra <sandeepjangra@gmail.com<mailto:sandeepjangra@gmail.com>>
Hello everyone,

  Like most others I am also running into some problems while running my word count example.
  I tried the various suggestion available on internet, but I guess it;s time to go on email

  Here is the error that I am getting:
  12/11/29 10:20:59 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments.
Applications should implement Tool for the same.
12/11/29 10:20:59 WARN mapred.JobClient: No job jar file set.  User classes may not be found.
See JobConf(Class) or JobConf#setJar(String).
12/11/29 10:20:59 INFO input.FileInputFormat: Total input paths to process : 1
12/11/29 10:20:59 INFO util.NativeCodeLoader: Loaded the native-hadoop library
12/11/29 10:20:59 WARN snappy.LoadSnappy: Snappy native library is available
12/11/29 10:20:59 INFO snappy.LoadSnappy: Snappy native library loaded
12/11/29 10:21:00 INFO mapred.JobClient: Running job: job_201210310210_0040
12/11/29 10:21:01 INFO mapred.JobClient:  map 0% reduce 0%
12/11/29 10:21:07 INFO mapred.JobClient: Task Id : attempt_201210310210_0040_m_000000_0, Status
java.lang.RuntimeException: java.lang.ClassNotFoundException: Class WordCount2$Map not found
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:1439)
at org.apache.hadoop.mapreduce.task.JobContextImpl.getMapperClass(JobContextImpl.java:191)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:605)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:325)
at org.apache.hadoop.mapred.Child$4.run(Child.java:270)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:416)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1232)
at org.apache.hadoop.mapred.Child.main(Child.java:264)
Caused by: java.lang.ClassNotFoundException: Class WordCount2$Map not found
at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:1350)
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:1437)
... 8 more

And here is the source code:

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.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

import java.io.IOException;
import java.util.StringTokenizer;

public class WordCount2 extends Configured implements Tool {

    public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        protected void map(LongWritable key, Text value, Context context) throws IOException,
InterruptedException {
            String line = value.toString();
            StringTokenizer tokenizer = new StringTokenizer(line);
            while (tokenizer.hasMoreTokens()) {
                context.write(word, one);


    public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable>

        protected void reduce(Text key, Iterable<IntWritable> values, Context context)
throws IOException, InterruptedException {

            int sum = 0;

            for(IntWritable value : values) {
                sum += value.get();
//                    while (values.hasNext()) {
//                          sum += values.next().get();
//                        }
            context.write(key, new IntWritable(sum));


    public int run(String[] args) throws Exception {
        Configuration conf = getConf();
        for (java.util.Map.Entry<String, String> entry: conf) {
            System.out.printf("%s=%s\n", entry.getKey(), entry.getValue());

        System.out.println("arg[0]= "+args[0] + " args[1]= "+ args[1]);

        Job job = new Job(conf, WordCount2.class.getSimpleName());





        FileInputFormat.setInputPaths(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        System.exit(job.waitForCompletion(true) ? 0 : 1);

        return 0;

    public static void main(String[] args) throws Exception {
        int exitCode = ToolRunner.run(new WordCount2(), args);

NOTICE: This e-mail message and any attachments are confidential, subject to copyright and
may be privileged. Any unauthorized use, copying or disclosure is prohibited. If you are not
the intended recipient, please delete and contact the sender immediately. Please consider
the environment before printing this e-mail. AVIS : le pr?sent courriel et toute pi?ce jointe
qui l'accompagne sont confidentiels, prot?g?s par le droit d'auteur et peuvent ?tre couverts
par le secret professionnel. Toute utilisation, copie ou divulgation non autoris?e est interdite.
Si vous n'?tes pas le destinataire pr?vu de ce courriel, supprimez-le et contactez imm?diatement
l'exp?diteur. Veuillez penser ? l'environnement avant d'imprimer le pr?sent courriel

View raw message