How do redundancy and high availability differ in a data centre context?

Redundancy and high availability are two critical concepts in the design and operation of data centres that serve different yet complementary purposes.

Redundancy refers to the duplication of critical components or systems within a data centre to prevent single points of failure. This means that if one component fails—be it a server, power supply, network path, or even data storage—the redundant system can take over without interrupting service. In essence, redundancy is a strategic approach to ensure that there are backup resources in place, allowing the data centre to continue functioning even when certain elements fail.

On the other hand, high availability is primarily concerned with ensuring that services are consistently available to users without interruption. High availability systems are designed for continuous operation, minimizing downtime and providing reliability. This can be achieved through various strategies, including load balancing, failover techniques, and ensuring that there are always active systems ready to handle requests. While redundancy is part of the picture that enables high availability, high availability encompasses broader strategies aimed at ongoing service delivery.

Understanding these two concepts highlights their distinct roles in creating resilient infrastructure in a data centre. Redundancy is about the physical or logical duplication of components, while high availability is about maintaining service continuity and minimizing disruption to users.