hadoop-common-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Shi Yu <sh...@uchicago.edu>
Subject Create a single output per each mapper
Date Tue, 13 Dec 2011 04:45:49 GMT

Suppose I have two mappers, each mapper is assigned 10 lines of 
data. I want to set a counter for each mapper, counting and 
accumulating, then output the counter value to the reducer when 
the mapper finishes processing all the assigned lines.  So I 
want the mapper outputs values only when there is no further 
incoming data (when that mapper closes). Is this doable? How? 


View raw message