##########################################	Tasktracker accept some mappers and reducers from jobtrackerserver, and run the mapperTasks and reducerTasks.#	It returns states of its tasks (succeed or failed) and the addresses of mapper result files to jobtrackerserver.##	@author Yang Fan(fyabc) #	@author Kai Yao(yaokai)######################################### TaskTracker : module {	PATH : con "/appl/MR/mapreduce/tasktracker.dis"; 	init : fn(); 	runMapperTask : fn(mapper : ref MRUtil->MapperTask) : int;	runReducerTask : fn(mapperFileAddr : string, reducer : ref MRUtil->ReducerTask) : (int, string);};