projectHints - Additional notes on the MapReduce project An...

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Additional notes on the MapReduce project An high-level overview of the system is shown below. Mappers read data of the form <key, data> from the input Fles. In general, a parallel Fle system can be used that allows each mapper to read from any Fle. In our system Fles will logically be readable by multiple mappers, but will be physically stored on each node on which one or more mappers run. Mappers take the data and based on the value if the key send the data to a unique reducer. Reducers take all of the data they have received from a mapper and perform a computation that reduces the data values to the desired output. Mappers can also perform a combine functions that combines the data from multiple data items with the same key into a single data item before sending it to a reducer. In the word count problem, the input data will be a list of words. The word is the key , and the data is the number of words, which will not actually be part of the input, but instead will be assumed to be
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This note was uploaded on 02/19/2012 for the course ECE 563 taught by Professor Staff during the Spring '08 term at Purdue University.

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projectHints - Additional notes on the MapReduce project An...

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