I believe that bytes read is the total volume of data read into the mappers, whereas local bytes read refers to the bytes read from map tasks which could be scheduled on machines that already held local copies of their inputs. So the ratio denotes a rough measure of scheduler locality efficiency.
- Aaron On Tue, May 19, 2009 at 12:54 PM, Foss User <foss...@gmail.com> wrote: > When we see the job details on the job tracker web interface, we see > "bytes read" as well as "local bytes read". What is the difference > between the two? >
