Final answer:
When a primary HA device stops replying to heartbeat, the secondary device initiates a failover to take over as the primary device and ensure service continuity.
Step-by-step explanation:
If a primary HA device stops replying to heartbeat, this typically indicates that the device has become non-operational, either due to a failure or a network issue. Heartbeat is a signal sent between the primary (active) device and the secondary (standby) device in a High Availability (HA) pair to monitor each other’s status. If the secondary device detects a loss of heartbeat for a predefined period, it will assume that the primary device has failed and will initiate a failover process. During this failover, the secondary device takes over the role of the primary device to ensure continuity of service with minimal disruption.
In an HA configuration, it is crucial to minimize downtime, and automatic failover is one of the key mechanisms to achieve this. Networks and services that require high availability, like databases, web servers, and applications, rely on HA systems to maintain operations during device or system failures.