The relationship between Jobtracker and Tasktracker

Jobtracker corresponds to NameNode

Tasktracker corresponds to DataNode

DataNode and Namenode are for data storage.

Jobtracker and Tasktracker are for mapreduce execution.

A few of the main concepts in MapReduce, MapReduce can be divided into such a number of execution clues:

Jobclient,jobtracker and Tasktracker.

1. Jobclient will use the Jobclient class to package the application's configured parameters into a jar file on the client side to be stored in HDFs.

and submits the path to Jobtracker, and then creates each task (i.e. Maptask and reducetask) by Jobtracker

and distribute them to various tasktracker services to perform

2, Jobtracker is a master service, after the software start Jobtracker receive job, responsible for scheduling job each subtask task run on Tasktracker,

and monitor them, and rerun it if a failed task is found. In general, Jobtracker should be deployed on separate machines.

3. Tasktracker is a slaver service running on multiple nodes. Tasktracker actively communicates with Jobtracker, receives jobs, and is responsible for performing each task directly.

Tasktracker all need to run on Datanode in HDFs.

The relationship between Jobtracker and Tasktracker