I have service running on Google Compute Engine. I've got few instances in Europe in a target pool and few instances in US in a target pool. At the moment I have a domain name, which is hooked up to the Europe target pool IP, and can load balance between those two instances very nicely.
Now, can I configure the Compute Engine Load Balancer so that the one domain name is connected to both regions? All load balancing rules seem to be related to a single region, and I don't know how I could get all the instances involved.
Thanks!
You can point one domain name (A record) at multiple IP addresses, i.e. mydomain.com -> 196.240.7.22 204.80.5.130, but this setup will send half the users to the U.S., and the other half to Europe.
What you probably want to look for is a service that provides geo-aware or geo-located DNS. A few examples include loaddns.com, Dyn, or geoipdns.com, and it also looks like there are patches to do the same thing with BIND.
You should configure your DNS server. Google does not have a DNS service, as one part of their offering, at the moment. You can use Amazon's Route 53 to route your requests. It has a nice feature called latency based routing which allows you to route clients to different IP addresses (in your case - target pools) based on latency. You can find more information here - http://aws.amazon.com/about-aws/whats-new/2012/03/21/amazon-route-53-adds-latency-based-routing/
With Google's HTTP load balancing, you can load balance traffic over these VMs in different regions by exposing via one IP. Google eliminates the need for GEO DNS. Have a look at the doc:
https://developers.google.com/compute/docs/load-balancing/
Hope it helps.
来源：https://stackoverflow.com/questions/21060404/one-domain-name-load-balanced-over-multiple-regions-in-google-compute-engine