Home > Communication Service Provider Solutions > Telecom Multicloud Foundation > Canonical > Guides > Reference Architecture—Canonical Charmed OpenStack (Ussuri) on Dell EMC Hardware > High availability in MAAS
MAAS is a mission-critical service that provides infrastructure coordination upon which cloud infrastructures depend. High availability in the region controller is achieved at the database level. The region controller will automatically switch gateways to ensure the high availability of services to network segments in the event of a rack failure.
MAAS can scale from a small set of servers to many racks of hardware in a data center. High-bandwidth activities (such as the initial operating system installation) are handled by the distributed gateways enabling massive parallel deployments.
The following diagram represents the logical design of MAAS and the high availability of its components: