The ResourceManager is the central authority of the Yarn cluster. It has two main components:
- Yarn - Scheduler (S) (The Scheduler is responsible for allocating resources)
- 8032 – Default port number
- 8050 – Default port number when you create your cluster using Ambari.
- 8025 - conf yarn.resourcemanager.resource-tracker.address
See Scheduler port
YARN supports the notion of resource reservation via the ReservationSystem, a component that allows users to specify a profile of resources over-time and temporal constraints (e.g., deadlines), and reserve resources to ensure the predictable execution of important jobs.
Restart is a feature that allow him to keep functioning across restarts and also makes the down-time invisible to end-users.