##########################################	The JobTracker module run the job.#	It assigns and coordinates all the tasktrackers.#	When the job is started, Jobtracker will produce mapperTasks and reducerTasks, and then shoot them to different tasktrackers.#	Jobtracker will monitor the states of tasktrackers and tasks, #	and do some steps ,such as change tasks to other tasktrackers if some tasks are failed or some tasktrackers are broken.#	#	@author Kai Yao(yaokai)#########################################JobTracker : module {		PATH : con "/appl/MR/mapreduce/jobtracker.dis"; 		init : fn(); 		submitJob : fn(config : ref Jobs->JobConfig) : int;		startJob : fn(id : int) : int; 		updateTaskTrackers : fn(taskTracker : ref MRUtil->TaskTrackerInfo) : int;		 ###### debug		getJob : fn(id : int) : ref Jobs->Job;		produceMapper : fn(job : ref Jobs->Job) : int;		produceReducer : fn(job : ref Jobs->Job) : int;						 		shootMapper : fn(mapper : ref MRUtil->MapperTask) : int;		shootReducer : fn(reducer : ref MRUtil->ReducerTask, mapperFileAddr : string) : int;######				mapperSucceed : fn(task : ref MRUtil->MapperTask, mapperFileAddr : string) : int;		reducerSucceed : fn(task : ref MRUtil->ReducerTask) : int;		mapperFailed : fn(task : ref MRUtil->MapperTask) : int;		reducerFailed : fn(task : ref MRUtil->ReducerTask) : int;		reducerFailedonMapper : fn(task : ref MRUtil->ReducerTask, failedAddr : string) : int;};