We use DNS-based load balancing along with an HA pair of load balancers in each datacenter. If the DNS health check fails, we stop sending traffic to a failing frontend LB. If failing LB is dead, we move its IP to the other one.
DNS TTL is not as big of an issue today as it was 5-10 years ago, when idiotic ISPs were trying to save on DNS resolving by ignoring TTLs. Nowadays you see an almost perfect drop in traffic when switching off a load balancer. Only bots and some weird exotic ISPs may keep sending traffic to a disabled box for up to an hour or two, but since DNS LB is only used to handle real emergency outages and for planned maintenance we could move LB IPs around, I really do not see it as a big enough issue to stop using the DNS LB magic :-)
DNS TTL is not as big of an issue today as it was 5-10 years ago, when idiotic ISPs were trying to save on DNS resolving by ignoring TTLs. Nowadays you see an almost perfect drop in traffic when switching off a load balancer. Only bots and some weird exotic ISPs may keep sending traffic to a disabled box for up to an hour or two, but since DNS LB is only used to handle real emergency outages and for planned maintenance we could move LB IPs around, I really do not see it as a big enough issue to stop using the DNS LB magic :-)