Web Caching and Replication

13.5. Dynamic Content

Dynamic objects are generated by programs that run on servers every time the corresponding objects are accessed, in order to produce a different object for every access. Responses from search engines or stock-quote sites provide typical examples of dynamic objects.

Understandably, proxies try to identify and not cache dynamic objects, although the example from Section 13.3.3 shows that dynamic objects cannot always be identified reliably. On the other hand, caching dynamic pages promises a disproportionately high performance payoff. Indeed, since each access returns different information, these pages are more likely to be revisited multiple times than static pages. One study of Web accesses shows an 85 to 87 percent rate ...