Load Balancers need static IPs

Here's how we solve this.<p>We host our DNS with DNS Made Easy, but you could also run your own DNS servers. (We actually have a pair of EC2 instances that we configured as DNS servers and then shut them down, so we're paying a minimal amount for them, but can spin them up very quickly the next time DME is hit with a DDOS.)<p>We query the ELB CNAME periodically and check its IP. If the IP changes, we update our corresponding A records with the new IP. It's a small amount of code and a cronjob that runs every 5 minutes.<p>Elegant? No. Get the job done? Absolutely.

If you could use a cname for your MX record, what are the benefits of using ELB over what's already in place (weighted mx priorities, with the ability to relay mail away automatically on failure from AWS) ?<p>Also there's additional cost involved in using ELB.<p>I would prefer having a good dns provider, low ttl, EIP, nginx w/haproxy.

I think you are blaming Amazon for a problem that is inherent in DNS, or possibly your approach to handling your DNS based features.<p>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:<p>*.example.com. 3600 IN MX 10 mail server.example.com.<p>Your mail servers can take the DNS synthesized domain from there I think.<p>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.<p>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'd rather say "load balancing needs SRV records" <a href="http://www.anta.net/nic/draft-andrews-http-srv-01.shtml" rel="nofollow">http://www.anta.net/nic/draft-andrews-http-srv-01.shtml</a><p>Is it widely implemented yet? Why not?

There's no need to use a load balancer for MX. The protocol it's self handles the problem of machines being offline. I agree with your point about not being able to point the root of your domain at an ELB though... I wasn't aware that you can't use a CNAME at the root.

I am not sure I understand the issue here. Sure, the AWS ELS offering is lacking and the issues re DNS are known. But just like any of their other offerings why try and shoe horn the product into your requirements. ?<p>Our service required a load balanced service and just like you we identified the issues and decided we could not live with the limitations.<p>So we brought up a small instance and run HAProxy on it to do all our load balancing. We assign an Elastic IP and we get to retain control, avoid the DNS issues, do https etc.<p>Essentially avoiding all the limitations of the Amazon offering.<p>AWS themselves use HaProxy for Elastic Load balancing and its solid.

Does the IP of the AWS load balancers ever change over time? Does anyone know the technical reasoning behind the requirement?

Yes, Amazon have been ignoring this problem for a while now. Here's a post I wrote on their forum over a year ago: <a href="http://developer.amazonwebservices.com/connect/thread.jspa?threadID=32044" rel="nofollow">http://developer.amazonwebservices.com/connect/thread.jspa?t...</a>

Is this a joke or irony? (The blog seems to be down right now).