MiAR-BFT: Efficient Leaderless Consensus Based on Multi-instance Asynchronous Running for Blockchain

The leaderless consensus, also known as multi-leader consensus, drives the agreements on multiple blocks independently and simultaneously across instances, enhancing consensus throughput significantly. To resolve the conflicts between transactions, which access the same state, from various instances, a global ordering on these blocks is involved to establish a serializable execution sequence. However, this process suffers from the synchronization among instances, where the faster instances have to align with the delayed ones in each round, raising the overall commit latency. In this study, we propose MiAR-BFT, which achieves asynchronous running of instances by eliminating the round-based global ordering, thereby minimizing the impact of slower instances on overall performance. Additionally, MiAR-BFT exploits a synchronization mechanism to handle the execution of conflicting transactions, ensuring the global consistency without sacrificing the performance. The extensive evaluation confirms the advantage of MiAR-BFT over other state-of-the-art comparisons, reaching up to 3× higher throughput under network fluctuations or node imbalances.