Hash routing and related approaches for clusters of web servers

Hash routing:

• How to make distributed proxy servers by URL hashing.

• Microsoft's Cache Array Routing Protocol (CARP).
  The Cache Array Routing Protocol (CARP) uses a hash function to divide the URL space among loosely coupled proxies.

• Keith W. Ross, Hash Routing for Collections of Shared Web Caches, IEEE Network, November/December 1997.
  This paper discusses hash-routing schemes for mapping requests to a collection of shared web caches residing on a LAN.

• Valloppillil & Cohen , Hierarchical HTTP Routing Protocol , 21 April 1997.
  This paper proposes that the administrator of an array of proxies use hashing to distribute the URL space among several web caches.
• Peter Danzig, NetCache Architecture and Deployment, 3rd International WWW Caching Workshop, June 1998.
  NetCache uses a hashing scheme to uniformly partition cache-to-cache traffic to that peer caches are responsible for non-overlapping URLs.

Other approaches for clusters of web servers:

• David Thaler and Chinya Ravishankar, Using Name-Based Mappings to Increase Hit Rates, IEEE/ACM Transactions on Networking, Vol. 6, No. 1, February 1998.
  This paper proposes a name-based mapping algorithm for use in a cluster of web caches with equivalent functionality and capacity. This mapping would be based on both the URL and on server addresses, for robustness when individual servers in a cluster go up or down.