Performance Evaluation of URL Routing for Content Distribution Networks

As the World Wide Web continues to grow in size, content is being co-located throughout the world in Content Distribution Networks (CDNs). These CDNs need entirely new methods of distributing client requests. The idea of a URL router has been introduced and in this dissertation the performance of URL routing is addressed. A URL router that uses HTTP redirection to automatically forward requests is architected. Significant open problems are finding effective ways to 1) reduce the size of the routing table, and 2) perform fast routing look-ups. These two problems must be solved in order for CDNs to become fully viable and thus are of significant interest. The first problem is solved by proposing the use of CRC32 as a means of reducing the length of a URL (typically 50 bytes) to a four-byte signature. The CRC32 method is shown to require less CPU resources, generate equal or smaller size digests, achieve equal collision rates, and simplify switching when compared to existing MD5-Bloom and CRC19 methods. The second open problem is solved by a new “Aggressive” hashing algorithm. The average look-up time performance of Aggressive hashing is compared to that of simple