Motivation

Reduce network load by caching shared documents from a set of clients at a proxy server.

What is the best policy for managing the fixed size cache?

Cache hit:

• cache has a "fresh" copy of document

• cache has a "potentially stale" copy of document confirmed to be fresh using a conditional GET request to origin server

Cache miss:

• document not in cache

• potentially stale document in cache confirmed to be stale and a new copy is retrieved from the origin server