Design Criteria

A web proxy is a transparent, trusted intermediary between web clients and web server for the purpose of making requests on behalf of clients and receiving responses from the server.

Requests are serviced internally or by passing them, with possible translation, on to other servers.

The proxy must address the following issues:

Caching

The proxy must cache web files. Web caches decrease latency at the cost of serving stale data.

Non-blocking

The web proxy must operate asynchronously.

Transparency

The proxy should be transparent to the client and server.

Correctness

The proxy should of course serve the page that the client requested.

The proxy should function correctly for any HTTP/1.0 GET, POST, or HEAD request. Cookies and authentication considerations can be ignored.

The following should also be kept in mind:

• The web proxy should tolerate many simultaneous requests. The web proxy will accept connections from multiple clients and forward them using multiple connections to the appropriate servers.
• No client or server should be able to hang the web proxy by refusing to read or write data on its connection.
• The cache should be coherent.