Hi,

Number of mappers = number of workers
Number of partitions = (multiplier * (number of workers) ^ 2 ) by default
(multiplier = 1 by default)

Lukas

On 22.9.2014 23:18, xuhong zhang wrote:

I know that the number of mappers equals to the number of worker *  mapred.tasktracker.map.tasks.maximum

How about the number of partitions? 

Thanks

--
Xuhong Zhang