Fault-tolerant scaleable multicast algorithm with piggybacking approach on logical process ring

A novel reliable, totally ordered multicast protocol on a single logical process ring (called FTSM) is presented. It guarantees totally ordered and atomic delivery of multicast messages in the presence of message loss, site crashes and network partitioning. By placing sequence numbers on messages, a process holding a virtual token multicasts totally ordered messages. Atomic delivery of multicast messages is achieved by piggybacking stable and acknowledged information on the part of both sender and receivers. Virtual token passing and transmission of control messages are piggybacked onto ordered data messages without requiring additional communication overhead. Individual processes handle token passing and control information by applying a local heuristic. FTSM is scaleable because its overhead on achieving total ordering and atomicity does not depend on the size of the process group. Implementation demonstrates that FTSM achieves superior performance over existing protocols in the same hardware setting