Cache Array Routing Protocol

HTTP

Persistence Compression HTTPS QUIC
Request methods
OPTIONS GET HEAD POST PUT DELETE TRACE CONNECT PATCH
Header fields
Cookie ETag Location HTTP referer DNT X-Forwarded-For
Response status codes
301 Moved Permanently 302 Found 303 See Other 403 Forbidden 404 Not Found 451 Unavailable for Legal Reasons
Security access control methods
Basic access authentication Digest access authentication
Security vulnerabilities
HTTP header injection HTTP request smuggling HTTP response splitting HTTP parameter pollution
v t e

The Cache Array Routing Protocol (CARP) is used in load-balancing HTTP 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) and the Microsoft Internet Security and Acceleration Server as well as F5 Networks BIG-IP devices.