What is High Availability?

High Availability (HA) refers to a system's ability to operate continuously without failure for a defined period. HA is achieved by minimizing downtime, which is often measured in terms of 'nines' (e.g., 99.999% availability). This is typically accomplished through redundancy, failover mechanisms, and robust error handling. HA systems are commonly used in critical infrastructure, data centers, and applications where even short periods of downtime can have significant consequences.