The Cache Array Routing Protocol (CARP) is used in load-balancing

HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, ...

requests across multiple proxy cache servers. It works by generating a hash for each URL requested. A different hash is generated for each URL and by splitting the hash namespace into equal parts (or unequal parts if uneven load is intended) the overall number of requests can be distributed to multiple servers. Implementations include Apache Traffic Server,

Squid (software) Squid is a caching and forwarding HTTP web proxy. It has a wide variety of uses, including speeding up a web server by caching repeated requests, caching web, DNS and other computer network lookups for a group of people sharing network res ...

and the

Microsoft Internet Security and Acceleration Server Microsoft Forefront Threat Management Gateway (Forefront TMG), formerly known as Microsoft Internet Security and Acceleration Server (ISA Server), is a discontinued network router, firewall, antivirus program, VPN server and web cache from Mic ...

as well as F5 Networks BIG-IP devices.

External links

Cache Array Routing Protocol v1.0 draft
{{web-stub Hypertext Transfer Protocol