Broadcast Protocols for Distributed Systems

We present an innovative approach to the design of faultprocessors agree on exactly the same sequence of broadcast tolerant distributed systems that avoids the several rounds of message exchange required by current protocols for consensus agreement. The messages. approach is based on broadcast communication over a local area It is easy to demonstrate that placing a total order on network, such as an Ethernet or a token ring, and on two novel protocols, broadcast messages, so that every working processor procthe Tram protocol, which provides efficient reliable broadcast communiesses the same messages in the same order, provides an cation, and the Total protocol, which with high probability promptly immediate solution to the agreement problem. Once this total places a total order on messages and achieves distributed agreement even in the presence of fail-stoo. omission. timing, and communication faults. order is determined, distributed actions can be carried out Reliable distributed operations such as locking, update and commitment, using simple sequential fault-tolerant algorithms. The strategy typically require only a single broadcast message rather than the several is very efficient: for example, locking records in a distributed tens of messages required by current algorithms. database typically requires only a single broadcast message to claim a lock and a single broadcast message to release it.