DNS-Based Global Server Load Balancing#

Global server load balancing (GSLB) directs users to the nearest or healthiest regional deployment. The most common approach is DNS-based: the authoritative DNS server returns different IP addresses depending on the querying client’s location, the health of backend regions, or configured routing policies.

When a user resolves app.example.com, the GSLB-aware DNS server considers the user’s location (inferred from the resolver’s IP or EDNS Client Subnet), the health of each regional endpoint, and the configured routing policy. It returns the IP address of the best region for that user.