Resource Manager

We know that YARN has introduced a new cluster management architecture. One of the new components of this architecture is Resource Manager. Resource Manager has somewhat limited functionality compared to Job Tracker. In the previous model, Job tracker was responsible for taking care of all the activity and its status in the cluster, whereas Resource Manager is responsible for the following:

• Assigning an ID to a new job submitted by a client
• Initiating a new daemon service called Application Master on the available Node Manager and assigning the job to this Application Master for further execution and handling
• Managing and assigning resources across clusters in the form of containers.

In Hadoop V1, we had only one Job Tracker. In case of any failure in Job Tracker, the whole cluster execution will collapse. Now, with Hadoop v2, there is also a backup Resource Manager that can replace the original in the case of any failure.