A Performance Study on the Signal-On-Fail Approach to Imposing Total Order in the Streets of Byzantium

Any asynchronous total-order protocol must somehow circumvent the well-known FLP impossibility result. This paper exposes the performance gains obtained when this impossibility is dealt with through the use of abstract processes built to have some special failure semantics. Specifically, we build processes with signal-on-fail semantics by (i) having a subset of Byzantine-prone processes paired to check each other's computational outputs, and (ii) assuming that paired processes do not fail simultaneously. By dynamically invoking the construction of signal-on-fail processes, coordinator-based total-order protocols which allow less than one-third of processes to fail in a Byzantine manner are developed. Using a LAN-based implementation, failure-free order latencies and fail-over latencies are measured; the former are shown to be smaller compared to the protocol of Castro and Liskov which is generally regarded to perform exceedingly well in the best-case scenarios