Cardinality of ReduceCopiers to map outputs

[Pedro Costa <ps...@gmail.com>]

Hi,



1 - I would like to know if a Map Task can produce more than 1 map
output per execution?

2 - A Map Task can't be reused, right? When a Map Task instance
produced a map outputs, this instance will end, right?

3 - I would like to know if a ReduceCopier will fetch only 1 map
output at a time and saves it in a file or in memory before merging
them? For example, if we've a ReduceCopier that fetches 4 map outputs,
the reduce will save the 4 outputs in separate and only after all map
outputs are copied to the reduce side, that the ReduceCopier will
merge them, right?



Thanks,
--
Pedro



-- 
Pedro