"many clients, especially game consoles and other consumer electronics, only use one IP address returned from the DNS query."
Is this referring to Netflix?
Is this referring to Netflix?
That certainly sounds like this doesn't it?
IIRC, Amazon.com doesn't use ELB, they use some proper load balancers (with DNS above) in front of several Regions of ELBs.
I wonder if there's a market for global load balancing + advanced DNS tricks as a service, even if you're using Amazon entirely. Generally extending Amazon's IaaS with features Amazon should implement hasn't been a great strategy, as Amazon eventually implements an inferior but cheaper or easier (or at least default) solution for non-core parts.
Kind of surprised to see www.amazon.com goes to DC for me (from SF), though. It's possible it's all in US-East, across all the AZ's, and just has localized sites like co.uk in other places.
You probably implement Geo, health, and load based optimization in the DNS layer and also in the physical load balancers. A single host out of ~30 dying at Site A doesn't affect how the DNS load balancing responds, but a critical number does.
Due to broken DNS implementations in the wild, you ideally keep your per-site load balancers up in as many situations as possible (even if load must be shed, you keep core network and load balancers up) and redirect traffic from there to other sites.
For larger sites, the big choice is running a single AS global network where IPs can move between datacenters vs. running each datacenter as a separate network. Advantages and disadvantages to each.
The big disadvantage of all of this is you're now spending a few million a month on salaries, infrastructure (various PoPs, network gear, etc.) before you've bought a single server or served a single page. Not so lean.
So a business opportunity kicks in. That's how the cloud revolutionizes computing.
(on the front end, you should probably also be doing CDN+ (caching, WAN TCP acceleration, DoS prevention) too.)
[also, wow, I didn't realize you were the "famous" Zhou Tong.]
In any case, AWS is probably closest to this kind of revolution, as they already have different types of managed database services (relational, object, in-memory and key-value). They also have Route 53, which is Anycast-based and CloudFront.
[What's right/wrong/surprising with my identity?]
[I wasn't following the bitcoin stuff as it happened, and then later read about bitcoinica (we actually use the difficulties with hosting providers you faced as an example with our unlaunched product...). I didn't know you were on HN -- awesome. (you are probably one of the world's experts on problems with service provider internal security, now, although it was expensive education). And handling things by paying everyone out was a much better decision than most startups after a breach.]
[The first line of the comment was intended to keep this on-topic. I didn't really have any financial interest in Bitcoinica at the time of the hack. A major management handover took place three weeks before that and the 100% of company was sold in 2011. The community assumed that I was still the owner but it's simply not true. The hacked mail server (the "root cause") didn't belong to me either. But yes, I learned a lot by being both an insider and an outsider, and these are fortunately free lessons. I still follow some of the valuable experience in dealing with Bitcoinica's infrastructure in my new project, which doesn't deal with money. Startup infrastructure has a big market. Now I use KVM to build a small private cloud for my new project on top of dedicated server(s) simply because I love the flexibility of cloud deployments. If someone brings that to developers who are not sysadmins, it'll be cool.]
Check where amazon.co.jp goes ;)
Considering most active domains have MX records under the root host name (like example.com.), CNAMEs won't work for these hostnames.
If there's native implementation for an "ALIAS" record which only points to the corresponding A record of the target, then it will work anywhere.
This is only true if you have a stable level of traffic, IIRC. If they have to scale the ELB up or down the IPs will change.