Techniques for internet load balancing for servers

[carl_townshend]

Hi all

If I hosted an online internet site which I wanted to be access globally across multiple datacentres, how would I achieve this? would it be via DNS ? or some other load balancer? how would it work ?

also I hear about anycast, how does this work? is that done via BGP and how ?

cheers

[rfalconer.sffcu]

You can use either a hosted global LB service from an external provider, like Akamai. Or you can set up your own global load balancing system with most, if not all, of the leading application delivery controller vendors.

Any of these should be able to do geo-location so that the traffic will be routed to the closest data center to the source of the request.

[carl_townshend]

How  is the closest to source routing done by these providers?

[rfalconer.sffcu]

It's done by source IP address. All IP address blocks are registered to someone and these products know who registered the IP and where it's located.

For example, go to this site:

http://www.ipligence.com/geolocation

Enter 72.163.4.161, which is cisco.com. It will show as San Jose, CA as the location. Based on that info, maybe it will send traffic to your Los Angeles hosted location instead of to your New York location.