Replication for a distributed multimedia system

Replicating data and services at multiple networked computers increases the service availability of distributed systems. This paper presents the design and implementation architecture of a replication mechanism for a distributed multimedia system medianode which is currently developed as an infrastructure to share multimedia-enhanced teaching materials among lecture groups. With the replication mechanism, medianode provides enhanced access to presentation materials in both connected and disconnected operation modes. The main contribution of this paper is the identification of new replication requirements in distributed media systems and a multicast-based update propagation mechanism by which not only the update events are signaled, but also the updated data are exchanged between replication managers.