Tuesday 4 April 2017

Hadoop server roles

Hadoop server roles



There are mainly three machines in Hadoop deployment.

  1. Master nodes. 
  2. Slave nodes. 
  3. Client nodes.
1. Master nodes: 
  • Master nodes mainly will do two things. 
    • How and where the data is storing. 
    • How to process the stored data in parallel way. 
  • Master node having master daemons 
  • Master daemons are Name node and Job Tracker 
  • Name node coordinates with HDFS to store the data 
  • Job Tracker coordinates with MapReduce to process the data in parallel way. 
2. Slave nodes
  • Slave nodes will store the actual data (raw data), and running the computations over the data 
  • Slave nodes having slave daemons. 
  • Slave daemons are Data node and Task tracker. 
  • Data node is slave to the Name node
    • Data node will communicate with Name node to receive the instructions. 
  • Task tracker is slave to the Job tracker
    • Task tracker will communicate with Job tracker to receive the instructions. 
  • So, Slave Daemons work as per the Master Daemons instructions.
3. Client nodes
  • The main role of client node is to load the data into the cluster. 
  • Submit the MapReduce jobs. 
  • MapReduce job describes how that data should be processed. 
  • Client node will receives the final results from finished jobs.

Thanks for your time.
-Nireekshan