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From "Cogan, Peter (Peter)" <Peter.Co...@alcatel-lucent.com>
Subject Set the number of maps
Date Thu, 01 Nov 2012 13:43:13 GMT

I understand that the maximum number of concurrent map tasks is set by mapred.tasktracker.map.tasks.maximum
 - however I wish to run with a smaller number of maps (am testing disk IO). I thought that
I could set that within the main program using

conf.set("mapred.tasktracker.map.tasks.maximuma", "4");

to run with 4 maps – but that seems to have no impact. I know I could just change the mapred-site.xml
and restart map reduce but that's kind of a pain. Can it be set from within the code?



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