YARN Timeline Service version 2

This service is responsible for collecting different metric data through its timeline collectors, which run in a distributed manner across Hadoop cluster. This collected information is then written back to storage. These collectors exist along with Application Masters—one per application. Similar to Application Manager, resource managers also utilize these timeline collectors to log metric information in the system. YARN Timeline Server version 2.X provides a RESTful API service to allow users to run queries for getting insights on this data. It supports aggregation of information. Timeline Server V2 utilizes Apache HBase as storage for these metrics by default, however, users can choose to change it.