If you have n processes to evaluate, make a reducer that calls the process i when it receives key i, 1<=i<=n. Either replicate the data for the n reducers, or cache it for it to be read on the reducer side. The reducers will output the process id i and the performance.
On Sep 10, 2012, at 8:25 PM, Jason Yang wrote: > Hi, all > > I've got a question about how to make different mappers execute different > processing on a same data? > > Here is my scenario: > I got to process a data, however, there multiple choices to process this data > and I have no idea which one is better, so I was thinking that maybe I could > execute multiple mappers, in which different processing solution is applied, > and eventually the best one is chosen according to some evaluation functions. > > But I'm not sure whether this could be done in MapReduce. > > Any help would be appreciated. > > -- > YANG, Lin >
