Pesto: Cooking up High Performance BFT Queries

This paper presents Pesto, a high-performance Byzantine Fault Tolerant (BFT) database that offers full SQL compatibility. Pesto intentionally forgoes the use of State Machine Replication (SMR); SMR-based designs offer poor performance due to the several round trips required to order transactions. Pesto, instead, allows for replicas to remain inconsistent, and only synchronizes on demand to ensure that the database remain serializable in the presence of concurrent transactions and malicious actors. On TPC-C, Pesto matches the throughput of Peloton [20] and Postgres [21], two unreplicated SQL database systems, while increasing throughput by 2.3x compared to classic SMR-based BFT-architectures, and reducing latency by 2.7x to 3.9x. Pesto's leaderless design minimizes the impact of replica failures and ensures robust performance.