Tool: An Efficient and Flexible Simulator for Byzantine Fault-Tolerant Protocols

A Byzantine Fault-Tolerant (BFT) protocol protects a distributed system from faulty participants. To provide both liveness and safety, many such protocols assume they are dealing with a partially-synchronous network, which will eventually stabilize after a global stabilization time (GST). In a real-world network environment, however, there is no such guarantee of bounded transmission time for network packets. For this reason, even if a BFT protocol is mathematically proven to achieve both liveness and safety, its overall performance is difficult to analyze theoretically, especially if there are bad network conditions or adversarial behaviors. Accordingly, we propose a simulator for evaluating the performance of BFT protocols under various network conditions and attacks, and we implement it to empirically compare the performance of eight representative protocols. Experiment results show that our simulator can simulate 16 times as many nodes as an existing simulator supports (512 vs. 32), and it is over 500 times faster when simulating 32 nodes (38 milliseconds vs. 19.4 seconds).