Hi, Your concern about DNS is well-founded. For those clouds that support a static IP concept (like EIPs on AWS), the recommendation is to use static IPs on your load balancers (or any public-facing server), such that in the event of a failure you can launch a new load balancer and associate the same static IP with the new server. This eliminates the need to make any DNS changes. For those clouds that don't have static IPs, the situation is a bit less straightforward. What we recommend is to use a low TTL on your DNS A records, and if you need to launch a new load balancer, you update DNS with the new public IP. Not all browsers respect the published TTL (I'm looking at you, IE)...so it may be up to 30 minutes before users start accessing the correct IP. The ELB can be used to mitigate this issue, but it brings other potential pitfalls (as we saw with the AWS outage on October 22nd).