> The urban legend that DNS-based load balancing depends on TTLs (it doesn’t - since Netscape Navigator, clients pick a random IP from a RR set, and transparent

> The urban legend that DNS-based load balancing depends on TTLs (it doesn’t - since Netscape Navigator, clients pick a random IP from a RR set, and transparently try another one if they can’t connect) Sure but if it can connect but then pukes out on something like a bad ssl or broken app, it’s not going back and trying another host. So, when using dns for load balancing, it’s preferable to have a low ttl with a dns record tied to a host health check. If a host goes unhealthy it takes itself out of rotation, auto scaling brings a new one in, and it’s fully warmed up in a minute.