Problems running Manning's Hadoop in Practice 4.1 MapReduce code on Hadoop 1.0.3 - hadoop

Question

I am attempting to run the 4.1 example code from Manning's "Hadoop in Practice" at http://www.manning.com/lam/
I am running Ubuntu 10.4 using hadoop 1.0.3 java 6.
The examples from http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-single-node-cluster/, I used the wordcount example to verify the installation.
I then tried to running the 4.1 example using:
hduser#ubuntu:/usr/local/hadoop$ bin/hadoop jar MyJob.jar MyJob /user/hduser/4.1/input /user/hduser/4.1output
I get the error:
Exception in thread "main" java.lang.ClassNotFoundException: MyJob
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:247)
at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
The public run method in the example that runs and manning's code appear to be different.
I appreciate your assistance!

Answer 1

Give the complete path of the jar. For example, if MyJob.jar is present inside your home directory then : hduser#ubuntu:/usr/local/hadoop$ bin/hadoop jar /home/hduser/MyJob.jar MyJob /user/hduser/4.1/input /user/hduser/4.1output

Answer 2

I had the same problem with Hadoop 1.0.3.16 and java 6 but I managed to get the Manning example 4.1 working by adding job.setJar("/path/to/MyJob.jar"); after job.setJobName("MyJob"); I thought of making this change because I was getting a warning: WARN mapred.JobClient: No job jar file set. User classes may not be found. See JobConf(Class) or JobConf#setJar(String). Do you get the same warning Tariq?
I also tried adding job.setJarByClass(MyJob.class); instead but this did not work.
Cheers, Alex