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I want to print each step of my "map" after its execution on the console.
Something like
System.out.println("Completed Step one"); System.out.println("Completed Step two");
and so on
Is there a special command to do that or is it not possible at all, as System.out.println doesn't seem to work at all ?
Please guide
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A MapReduce job usually splits the input data-set into independent chunks which are processed by the map tasks in a completely parallel manner. The framework sorts the outputs of the maps, which are then input to the reduce tasks. Typically both the input and the output of the job are stored in a file-system.
They are sequenced one after the other. The Map function takes input from the disk as <key,value> pairs, processes them, and produces another set of intermediate <key,value> pairs as output. The Reduce function also takes inputs as <key,value> pairs, and produces <key,value> pairs as output.
You can use System.out.println(... To see whats been printed, open the jobtracker web console. Then navigate to your submitted job's link. On the Job page, you will see links to all your individual Map/Reduce tasks. Follow the links.. you will find a link that displays the dump of both the Standard output as well as the Standard error.
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