Appendix A. The JobConf Object in Detail

Everything in a job is controlled via the JobConf object; it is the center of the universe for a MapReduce job. The framework will take the JobConf object and render it to XML; then all the tasks will load that XML when they start. This section will cover all the relevant methods (as of Hadoop Core 0.19.0) and provide some basic usage examples.

The JobConf class inherits from the Configuration class. Because the JobConf object is the primary interface between the programmer and the framework, I'll detail all methods available to the user of a JobConf without distinguishing which methods come from the Configuration base class. I suggest that you create and use only JobConf objects. By default, a new JobConf ...

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