So the design of this protocol will be critical to the adaptive caching system. As a cache group becomes larger, its traffic, overhead and workload increase. The configuration protocol needs to balance these requirements to reduce the overhead within each of these groups. The cache groups must also be able to dynamically adjust to the addition and deletion of caches, routing and load changes, application performance and tolerance to overhead. A number of issues applicable to all web-caching schemes threaten to interfere with such an infrastructure.
Some web designers are concerned about the possibility of obsolete data being served to end users.
Commercial content providers are also interested in collecting demographic information regarding page access statistics. With multiple copies of pages scattered through the network, the ability to verify that a page is an exact duplicate of the one on the original server becomes even more critical than it is today. Furthermore, such ubiquitous circulation of data makes it even more difficult to assure that no one but the authenticated client can obtain copies. For example, pages are sometimes assigned lifetimes of zero. She believes, however, that adequate lifetime information in each page and strict enforcement by all the caches can address any concerns about dated pages being served.