Web Caching and Replication

Chapter 9. Cooperative Proxy Caching

The main mission of a proxy server is to provide a shared cache to multiple clients. This shared cache allows a client to take advantage of a cached copy when the client retrieves an object for the first time if that object was previously requested by another client. Intuitively, the benefit from the shared cache increases with the size of the client population using it.

There are two potential problems in serving a very large client community. First, as the client population grows, so does the request rate that the proxy must process. We refer to the problem of handling the request rate as the load scalability problem. Second, a large client population is necessarily dispersed over a wide geographical area. ...