Hi All, In JobHistory Web UI under Job > "Map Tasks" I see something as follows: ... Started: <start time> Finished: <finish time> Elapsed: 12 mins, 5sec Diagnostics: *Average Map Time*: 1 mins, 40 sec Average Reduce Time: 12 sec Average Shuffle Time: 10 mins, 8 sec Average Merge Time: 1 sec ...
1) I wonder which sub-map phases "Map Time" contains (e.g. map function, sort, spill, merge, read and transfer corresponding filesplit from HDFS) 2) Does Reduce time covers Shuffle Time? What else does it cover? (write to hdfs, etc) 3) Is Average Merge time related with map or reduce? (since they both have merge phases) Best, Efe
