All right, I got it~Thank you very much. 2012/9/11 Harsh J <ha...@cloudera.com>
> Hey Jason, > > While I am not sure on whats the best way to automatically "evaluate" > during the execution of a job, the MultipleInputs class offers a way > to run different map implementations within a single job for different > input paths. You could perhaps leverage that with duplicated (or > symlinked?) input paths. > > Otherwise, perhaps do all the N types of computation in a single map() > call, and judge the time inside it at the end of all, before emitting? > > On Tue, Sep 11, 2012 at 9:03 AM, Jason Yang <lin.yang.ja...@gmail.com> > 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 > > > > > > -- > Harsh J > -- YANG, Lin
