Using a content distribution network to improve Web server performance
By Linda Gail Christie
The scalability of Web servers to meet growing user demand is one of the biggest challenges faced by content providers. Content providers typically house server(s) at one location. So user requests from all over the world travel over the Internet to this location, eventually clogging bandwidth and slowing response times.
The "hub" model, though, is not the answer to Web availability. This model does not provide the shortest Internet path link; and should the hub fail, users will be cut off from their content. Therefore it's vital to distribute content to geographically dispersed locations via a content distribution network (CDN).
To reduce access latency and bandwidth usage, content distribution networks push content closer to the edge of the network--keeping frequently requested documents close to the location where they are accessed. Intelligent replication based on usage eliminates the need to reach the origin server(s). With caching, content providers can serve a larger client base without having to upgrade either their network or server infrastructure.
Caching has the added benefit of dramatically reducing the cost of storage and replication of content for mirrored servers, since caching stores only frequently accessed content. More importantly, caching provides improved connection and response times to end users.
As more robust applications come online, the need for CDN infrastructure has become more imperative.
For additional information about CDNs read, "Exodus ReadyCache Content Distribution Service," by Dr. Mohan Sharma at http://www.exodus.net/pdf/whitepapers/ms_cd_ready_cache.pdf.
About the author: Storage management tips are written by Linda Gail Christie, a contributing editor based in Tulsa, Okla.