The most important thing in job.jar is the Mapper class and Reducer class.
Because the tasktracker do not have these two classes. So hadoop will help
you create the job.jar and then transfer it to tasktracker.
This is hadoop's philosophy: move computation rather than moving data.
On Mon, Mar 15,
Hi,
When I'm running an hadoop example:
$ bin/hadoop jar build/hadoop-0.20.2-dev-examples.jar wordcount gutenberg
gutenberg-output
I've noticed that it's created a job.jar file with classes of the
hadoop-0.20.2-dev-examples jar. Why job.jar is created?
In the "Hadoop-Definitive Guide" book, it e
