Global Web Server Load Balancing
by admin on Jul.10, 2006, under Networking, load balancing
I am going to be blogging about Load balancing in the quite a bit in the near future. I will try to go in depth on different subjects as time allows but to start will a couple of links to some devices you might want to look into. If you want to load balance network devices in a single datacenter such as web servers, firewalls or VPN you can buy a Cisco device called a CSS or Content Services Switch. This device will load balance your network devices by setting up VIPs or Virtual IPs that you point your traffic to and the CSS will load balance to real servers. If you have a 7600 series router then you can buy this same device in Blade form. This load balancer is called a CSM or Content Switch Module.
The above is great for load balancing devices in a datacenter but what if you need to take this to the next level. If you want to load balance to multiple geographically diverse datacenters you can buy a Cisco GSS or Global Site Selector Appliances. This devices basically replaces your DNS servers and is able to load balance and failover DNS resolutions to different datacenters. This device talks to your CSS or CSM and determines not only if the resource is up but can track which datacenter is busier and even which datacenter is closest to the client’s request. I will blog more in detail at a later date on both of these platforms.
December 10th, 2007 on 12:32 am
No need to buy the Cisco GSS.
At its foundation, it is a DNS server with some special features.
You can get all of this as part of a hosted service where you just pay for the service, no hardware required.
December 10th, 2007 on 9:52 am
Yep, GSS is a fancy DNS server but it does tie into the CSS family as well for added functionality.
If you have a few domains and not a ton of requests it might be worth while going with a service but it has been my experience that if you have millions of requests a day and hundreds of domains the price for a service will become ridiculous. Sure it is a big purchase for a couple of GSSs but then you own them. A service might cost less in the short-term but over a year or two you might be paying double what it would have cost to buy the hardware yourself.