Global Server Load Balancing with DNS

What is global server load balancing?

DNS has enough limitations when it comes to load balancing across instances that it’s usually worth moving up the stack a bit. However, there’s one place where DNS excels: global server load balancing (GSLB). GSLB tries to route clients across multiple geographic locations (see the figure that follows). This can be for physical data centers of our own or for multiple regions in a cloud infrastructure. We see this most in the context of external clients routing across the public Internet. Clients will get the best performance by routing to a nearby location, bearing in mind that “nearby” in network terms doesn’t always match physical geography the way we’d expect.