*By the way this question is about Apache Hadoop Release 2.1.0-beta. Thanks,
2013/9/24 Efe Gencer <[email protected]> > 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 >
