This talk will discuss the challenges wide-area networks such as the Internet present for group communications and how these challenges were met by the design and implementation of a group messaging system called "Spread".
Specifically, I will discuss two aspects of the system. First, how overlay networks can effectively scale reliable group multicast, providing reliable wide-area message dissemination without requiring per-message end-to-end acknowledgments. Second, what unique problem arise when developing security protocols such as group key agreement and access control for fault-tolerant messaging systems and how we addressed these problems.
The talk will also present performance results for Spread on both local and wide-area networks.
The Spread system has been publicly released and used in various commercial and freely available applications for over 2 years. The types of applications range as widely as database replication, distributed event logging, online chat, distributed graphics rendering, and distributed certificate revocation management.