Caching proved so efficient that the need was soon seen for deploying multiple proxy servers that could communicate and work together to create a more robust system. If all queries failed to find a cached object, the proxy would then use HTTP to request the object from the Internet. This is especially important because the vast resources of the Internet, as well as its huge potential for marketing, sales, and other business activities, make the Internet an increasingly essential element for an organization's communications infrastructure. The result is single-hop resolution. The web browser, or a downstream proxy, will know exactly where each URL would be stored across the array of servers.
CARP has positive scalability.
CARP protects proxy server arrays from becoming redundant mirrors of content. This vastly improves the efficiency of the proxy array, allowing all servers to act as a single logical cache. CARP automatically adjusts to additions or deletions of servers in the array. The hashed-based routing means that when a server is either taken off line or added, only minimal reassignment of URL cache locations is required. CARP provides its efficiencies without requiring a new wire protocol.