Job Initialization in Hadoop

Job Initialization
● Puts the job in internal Queue
● Job Scheduler will pickup and initialize it
● Create a Job object and job being run
● Encapsulate its tasks ○ Book keeping info to track tasks status and progress
● Create list of tasks to run ● Retrieves number of input splits computed by the JobClient from the shared filesystem
● Creates one map task for each split. ● Scheduler creates the Reduce tasks and assigns them to taskTracker. ○ No. of reduce tasks is determined by the map.reduce.tasks.
● Tasks ID’s are given for each task