Load balancing between datacenters

[Tyler J. Wagner]

On 2012-09-06 14:03, Jesus arteche wrote:
> Hey guys,
> 
> I am trying to create a ha infrastructure. I would like to have my
> infrastructure in a cloud/vps provider in europe and a replica in USA. I
> will create load balancers in a HA mode. My problem comes up when I think
> how to share the floating ip. I mean in a datacenter with the same range of
> IP is not a problem...but when the datacenters are in different ranges of
> ip's ...it shouldn't work...
> 
> Any ideas about how to do it?
> 
> I'm using HAproxy and keepalive...

You cannot do it with one floating IP. Options:

1. Get your own /24, and BGP-announce the subnet from both locations. This
is what Google uses to make their DNS IPs 8.8.8.8 and 8.8.4.4 work globally
(taking you to the nearest server according to network path).

2. Build a load balancer in one of those locations, or a third one, which
proxies, possibly via a VPN, to both servers. This moves the failure point
forward.

3. Use DNS load balancing with a low TTL, along with a detection system to
remove the DNS entry of a failed server.

Regards,
Tyler

-- 
"All that is necessary for the triumph of evil is that good men do
nothing."
   -- Attributed to Edmund Burke