REACHING STRONG CONSENSUS IN THE PRESENCE OF MIXED FAILURE TYPES

The Strong Consensus (SC) is a variant of the conventional distributed consensus problem. The protocol designed for the SC problem requires that the agreed value among fault-free processors be one of the fault- free processor's initial value. The SC problem is re-examined with the assumption of mixed failure types (also referred to as the hybrid fau lt model). Compared with the features of the existing protocols, the u nderlying network topologies of the proposed protocol do not have to b e fully connected, the mixed failure types can be tolerated, and no pr ior information of the system's faulty status is required. The propose d protocol can tolerate a maximum number of faults to enable each faul t-free processor to reach an agreement with a minimum number of messag e exchanges. (C) 1998 Published by Elsevier Science Inc. All rights re served.