Hello all,
I have a question regarding the mappers. I can see from the logs that the start
time of the mapper is different from start time of logging. I am having a
problem because that time difference sometimes is few seconds, but other times
it is
For example, one mapper that is supposed to read 65 MB. Its start time is
12:30:53 whereis the logging start time is 12:33:01 and the end time is
12:33:20. All the laoded data are local to the same rack.
In a perfect run, these numbers are as follows: the start time is 18:15:45,
logging start time: 18:15:48, and end time: 18:16:02.
I am running a job of more than 2400 mapper. Because of the above problem,
instead of the job taking 15-20 mins on 14 machine ( it happened in few runs),
other times it is taking more than 70 mins. Any suggestions how to fix this
problem or what could possibly be causing it.
Thanks,
Iman
