9.3. Location Management
Following are the main alternatives for location management.
Broadcast queries: A proxy looking for an object issues a query to other proxies with which it cooperates.
Hierarchical caching: The cooperating proxies are arranged into a hierarchy and a proxy sends all locally missed requests to its parent in the hierarchy.
URL hashing: A hash function maps all possible URLs to individual proxies, so that each proxy becomes responsible for a well-known subset of all Web resources.
Directory-based cooperation: An explicit directory service tracks the whereabouts of cached objects.
9.3.1. Broadcast Queries
The earliest cooperation model, and one that is still popular, is based on broadcast queries. The basic idea of a broadcast ...