Apache Hadoop YARN (Yet Another Resource Negotiator) is a cluster management technology. It decouples MapReduce’s resource management and scheduling capabilities from the data processing component, enabling Hadoop to support more varied processing approaches and a broader array of applications. YARN, (or sometimes called as MR2), is an extended and an improved version of MR1. It was designed to enable greater sharing, scalability, and reliability of a Hadoop cluster. The MapReduce functionality has been replaced with a new set of daemons that opens the framework to new processing models.
Understanding YARN and it’s components
What is a Capacity Scheduler in Hadoop?