[aarmenaa]

True. On the other hand, if you control the clients and can guarantee their behavior then DNS load balancing is highly effective. A place I used to work had internal DNS servers with hundreds of millions of records with 60 second TTLs for a bespoke internal routing system that connected incoming connections from customers with the correct resources inside our network. It was actually excellent. Changing routing was as simple as doing a DDNS update, and with NOTIFY to push changes to all child servers the average delay was less than 60 seconds for full effect. This made it easy to write more complicated tools, and I wrote a control panel that could take components from a single server to a whole data center out of service at the click of a button.

There were definitely some warts in that system but as those sorts of systems go it was fast, easy to introspect, and relatively bulletproof.