Error in configuring object

[David Greer <da...@davidgreer.ca>]

Hi Everyone,

I'm experimenting with Hadoop and trying to get it running in
pseudo-distributed mode as described in Appendix A of Tom White's book
Hadoop The Definitive Guide.

I've got the MaxTemperature example working when there is *no* job or task
tracking daemons running. I didn't actually know that they were running
until I updated mapred-site.xml.  Baseline description:

Red Hat ES 5.3 (2.6.18-164.2.1.el5xen)
Hadoop 0.20.1+133 (Cloudera distro)

So we have two situations.

First:

mapred-site.xml as installed (no changes)
MaxTemperature example works


Second:

mapred-site.xml changed with:

<property>
  <name>mapred.job.tracker</name>
  <value>localhost:8021</value>
  <description>The host and port that the MapReduce job tracker runs
  at.  If "local", then jobs are run in-process as a single map
  and reduce task.
  </description>
</property>

Daemons stopped and started.
Log files checked.
Appears job and task daemons are running.
Try MaxTemperature example:

 hadoop MaxTemperature sample.txt output
09/10/28 14:01:28 WARN mapred.JobClient: Use GenericOptionsParser for
parsing the arguments. Applications should implement Tool for the same.
09/10/28 14:01:28 WARN mapred.JobClient: No job jar file set.  User classes
may not be found. See JobConf(Class) or JobConf#setJar(String).
09/10/28 14:01:29 INFO mapred.FileInputFormat: Total input paths to process
: 1
09/10/28 14:01:29 INFO mapred.JobClient: Running job: job_200910281355_0001
09/10/28 14:01:30 INFO mapred.JobClient:  map 0% reduce 0%
09/10/28 14:01:50 INFO mapred.JobClient: Task Id :
attempt_200910281355_0001_m_000000_0, Status : FAILED
java.lang.RuntimeException: Error in configuring object
        at
org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:93)
        at
org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:64)
        at
org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117)
        at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:354)
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:307)
        at org.apache.hadoop.mapred.Child.main(Child.java:170)
Caused by: java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at
org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:88)
        ... 5 more

This is repeated with what appears to be similar stack traces. I've hunted
around for the error message:

Error in configuring object

But I haven't had any luck finding others who seemed to have run into this.
Any hints on where to look next would be appreciated.

Cheers,

David Greer
djgreer.wordpress.com