YARN : Yet Another Resource Negotiator

YARN Architecture :

YARN Components:

Resource Manager  :

• Uses of resources across the Hadoop cluster 
• What are the resources available and who are using the resources in the cluster
• Negotiate resources
• Gives container to node manager to execute 

Node Manager :

• Runs on each Data node 
• Instead of having task tracker we have node manager to run
• Monitor the resources and report back to Resource manager 

Container  :

• It creates execution container which executed on worker/slave machine  of cluster
• Whatever the resources allocation you have from resource manager for the  execution of job like how much memory , cpu , its priority based on resources are allocated

Application Master : 

• Coordinates and manages  the manually submitted Map-Reduce job also handle life cycle of it
• Work with the resource manager to schedule task , to get the resources and based on that get help of node manager to execute the task on machine
• Managing life cycle of the application

1.0 - 2.0 :
Job Tracker = Resource Manager
Task Tracker = Node Manager