I think you are blaming Amazon for a problem that is inherent in DNS, or possibly your approach to handling your DNS based features.
Unless I've drunk too much AWS Koolaid, I'm fairly certain you can run wildcard DNS for just the MX records for your domain. That entry would look something like:
*.example.com. 3600 IN MX 10 mail server.example.com.
Your mail servers can take the DNS synthesized domain from there I think.
BTW, I agree serving naked domains is a bit of a PITA, (appengine problem too!) but you can solve that by assigning a few elastic IPs to a few web heads and use RR DNS for them, with some code to take them out if one fails. Zerigo, for one, supports doing something like this IIRC.
302 anyone using the naked domain to the www. I doubt it matters much load wise as it sounds as if your running subdomains for your app like we do at Loggly.
I just realized you are probably running CNAME wildcards for the subdomains as well, which wold conflict with the MX one. How about running separate records for each subdomain?
That sucks for email servers then, after all you can put MX records up until the cows come home, plenty of services will not accept from or deliver to your server if the reverse lookup is not working properly.
Comments
I think you are blaming Amazon for a problem that is inherent in DNS, or possibly your approach to handling your DNS based features.
Unless I've drunk too much AWS Koolaid, I'm fairly certain you can run wildcard DNS for just the MX records for your domain. That entry would look something like:
*.example.com. 3600 IN MX 10 mail server.example.com.
Your mail servers can take the DNS synthesized domain from there I think.
BTW, I agree serving naked domains is a bit of a PITA, (appengine problem too!) but you can solve that by assigning a few elastic IPs to a few web heads and use RR DNS for them, with some code to take them out if one fails. Zerigo, for one, supports doing something like this IIRC.
302 anyone using the naked domain to the www. I doubt it matters much load wise as it sounds as if your running subdomains for your app like we do at Loggly.
I just realized you are probably running CNAME wildcards for the subdomains as well, which wold conflict with the MX one. How about running separate records for each subdomain?
Even with separate records for each subdomain, I think you'd still have the problem.
You'd need to do: acme MX (mail_server_ip) acme CNAME (ELB hostname)
... but that isn't allowed. The problem is with the records conflicting, not with the wildcard.
Doesn't that give you trouble with the reverse lookups though?
Reverse lookups on Amazon are trouble either way. You can't control them.
That sucks for email servers then, after all you can put MX records up until the cows come home, plenty of services will not accept from or deliver to your server if the reverse lookup is not working properly.