MapReduceProposal

public interface Mapper<KIn, VIn, KOut, VOut> extends Serializable {
   void map(KIn key, VIn value, Collector<KOut,VOut> collector);
}

public interface Reducer<KOut,VOut> extends Serializable{
   VOut reduce(KOut key, Iterator<VOut>);
}

public interface Collator<VOut,R> {
   R collate();  
   void reducedResultReceived(Address remoteNode,  VOut remoteResult);
}