io.sort.factor -- The number of streams to merge at once while sorting files. This determines the number of open file handles.
How can I use this parameter to improve performance of mapreduce job?
My understanding from above description was If there are many spill records then increasing io.sort.mb as well as io.sort.factor will help in better performance. Increasing io.sort.mb helped but changing io.sort.factor (> 10) does not seem to improve/degrade performance of mapred job.