Meepo: Sharded Consortium Blockchain

Abstract

Blockchain performance cannot meet the requirement nowadays. One of the crucial ways to improve performance is sharding. However, most blockchain sharding research focuses on public blockchain. As for consortium blockchain, previous studies cannot support high cross-shard efficiency, cross-contract flexibility, shard availability, and strict transaction atomicity, which are the essential requirements but also the challenges in consortium blockchain systems. Facing these challenges, we propose Meepo, a systematic study on sharded consortium blockchain. Meepo enhances cross-shard efficiency via the cross-epoch and cross-call. Moreover, a partial cross-call merging strategy is designed to handle the multi-state dependency in contract calls, achieving cross-contract flexibility. Meepo employs a replay-epoch to ensure strict transaction atomicity, and it also uses a backup algorithm called shadow shard based recovery to improve the shard robustness. We implement Meepo on the AliCloud, using 32 shards in maximum, achieving more than 120,000 cross-shard TPS under the workload of 100,000,000 asset transactions.