Zhang, Jianying.

Peer-to-Peer (P2P) systems are characterized by direct access between peer computers, rather than through a centralized server. File sharing is the dominant P2P application on the Internet, allowing users to easily contribute, search and obtain content. The objective of this thesis was to design XYZ, a partially centralized, scalable and self-organizing lookup service for wide area P2P systems. The XYZ system is based on distributed hash table (DHT). A unique ID and a color assigned to each node and each file. The author uses clustering method to create the system backbone by connecting the cluster heads together and uses color clustering method to create color overlays. Any lookup for a file with a color will only be forwarded in the color overlay with the same color so that the searching space is minimized. Simulations and analysis are also provided in this thesis.