What sort of combining are you trying to achieve? Hadoop combining means that hadoop will collect the output from all the maps and guarantee that all the outputs that have the same key will be sent to the same reducer (you can find more details in "hadoop the definitive guide chapters 2 and 6).
On Tue, Oct 22, 2013 at 5:50 PM, Mike Schliep <schl...@cs.umn.edu> wrote: > For a class project my group and I are looking to experiment with > combining the output from Mappers on the same node or in the same rack. We > found the idea at > http://wiki.apache.org/hadoop/**HadoopResearchProjects<http://wiki.apache.org/hadoop/HadoopResearchProjects> > . > > According to > http://developer.yahoo.com/**hadoop/tutorial/module4.html<http://developer.yahoo.com/hadoop/tutorial/module4.html>the > output is already combined over all Mappers in a node. But we can not > find how this is happening. Can someone point us to where this combiner is > executed? > > Thanks, > Mike Schliep >
