Recent Blog Posts
Blogs » Archive for October 5th, 2007
Client-side Load Balancing Web 2.0 Apps is Voodoo
Digital Web recently published an article about “Client Side Load Balancing for Web 2.0 Applications“. I wanted to take a moment to explain why I think this load balancing technique is a bad idea. But first, here’s the concept in brief:
- Your web site is deployed in an identical fashion across a number of web servers.
- Your customer’s browser retrieves a list of web app servers from your server, say in XML format.
- The browser then “randomly selects servers to call until one responds”, and “has a preset timeout for each call. If the call takes greater than the preset time, the client randomly selects another server until it finds one that responds”.
No matter how long and hard I think about this concept, I can’t convince myself that it even sounds good in theory. Here’s why:
- We still have a single point of failure. What happens if our web application is not able to retrieve a valid list of servers?
- Correctly failing over is difficult and ungraceful. How much “preset time” should the client allow before trying another server? Is this waiting period acceptable to our customers? Can the application accurately tell the difference between a server …
Sponsored Links
Download sample chapters of any of our popular books.
Learn more with SitePoint books