Extended abstract to appear in the 16th International Symposium on DIStributed Computing (DISC) October 2002, Toulouse, France.
Full version: Technical Report LCS-TR-840 Massachusetts Institute of Technology, Laboratory for Computer, April 2002.
Our algorithm exhibits constant message delivery latency in the absence of failures, even during periods when participants join or leave. To the best of our knowledge, this is the first algorithm for totally ordered multicast in a dynamic setting to achieve constant latency bounds in the presence of joins and leaves. When failures occur, the latency bound is linear in the number of actual failures.
Our algorithm uses a solution to a variation on the standard distributed consensus problem, in which participants do not know a priori who the other participants are. We define the new problem, which we call Consensus with Unknown Participants, and give an early-deciding algorithm to solve it.