3 ms·
Solved problem via [geo] load balancers such as Azure Front door. The thing to keep in mind is that you need to assume a given DNS server (server server) doesn
by p_ing 2y ago
Solved problem via [geo] load balancers such as Azure Front door.
The thing to keep in mind is that you need to assume a given DNS server (server server) doesn't respect TTL. TTL should be considered a value that is ignored unless you operate the DNS server and clients. So while you update your TTL, some client in a remote-region-in-the-middle-of-nowhere is leveraging a DNS server that sets all TTL values to 10 days. Now you've got a client that cannot connect.
- kbench 2y agoThis is a really good point. It'd be the nature DNS of course. I guess my API Calls would try to encourage a TTL of a maximum to minimize the downtime. Remote region of nowhere that sets all TTLs to 10 days. Well, that sucks.
- p_ing 2y agoThe point is, you cannot rely on TTL. TTL could be hard coded on a server to 5 minutes or to 20 days. Doesn't need to be a BFE server, it could be a Comcast DNS for all you're aware. This is why DNS "failover" is never a good idea outside of a highly controlled (i.e., internal) environment.