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JobInProgress contains two sets of TaskInProgress instances:
Wiki Markup TaskInProgress maps\[\], an array holding one tip per split
Wiki Markup TaskInProgress reduces\[\], an array holding one tip per partition \\
Method initTask() fills out those tips. initTask also creates:
Wiki Markup hostMaps\[\], which cotains a mapping from a host to file split id's that the host is holding on DFS. \\
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JobInProgress also offers two methods for creating a !Task instance to run, out of maps\[\] and reduces\[\]: |
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InputFormat is an interface for instantiating file splits and the readers for map task.
Wiki Markup FileSplit\[\] getSplits(), creates an array of FileSplit for the job. A FileSplit is a span of a given file.
- RecordReader getRecordReader(), creates a reader for a given split.
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