Apache Hadoop YARN (Yet Another Resource Negotiator) is the cluster resource management technology in Hadoop version 2. The YARN provides multiple accesses for batch and real-time processing across multiple clusters and has the benefit over utilization of cluster resources during dynamic allocation. The chapter shows the YARN architecture, schedulers, resource manager phases, YARN applications, commands, and timeline server. The architecture of YARN splits the task into resource management and job scheduling. This is managed by Resource Manager and Node Manager. The chapter addresses the Timeline Server, which stores and retrieves the present and past information in a generic way.