| Delivering content from the information source to consumers has found a wide range of applications in networked systems. The challenges we face to meet the ever-growing demand on content delivery over the Internet include the large content size, the potentially large user population, and the high consumption of network resources. This dissertation addresses these challenges by employing overlay networks and enhancing their performance. First, fine-grained peer-sharing among replica servers for content distribution networks is proposed in order to improve the flexibility of these servers for handling client requests. This method is especially effective in accommodating bursty requests for a specific file or a specific set of files. Second, a novel approach is proposed to improve the search efficiency for peer-to-peer networks by assigning each node a unique ID and organizing nodes into an unstructured overlay supplemented with the predecessor and successor pointers. This method can significantly reduce the message duplication compared to traditional unstructured P2P networks while achieving comparable maintenance overhead. Third, overlay multicast is prone to unexpected partitions due to node departures.To speed up the recovery process, a cooperative failure detection scheme and a proactive tree recovery mechanism are proposed. These approaches can reduce the service disruption due to node departures and failures and improve the failure-resilience of overlay multicast.; Keywords. Overlay networks, content delivery, content distribution networks, peer-to-peer networks, overlay multicast... |
