Cross-Shard Transaction Processing For Sharded Permissioned Blockchain

Blockchain,as a tamper-proof and decentralized distributed system,has attracted significant attention from the academic and industrial communities.However,traditional blockchain systems suffer from low throughput,only capable of processing tens to hundreds of transactions per second,and they struggle to scale to support large-scale systems.These limitations restrict the scope of their applications in the business sector.To address these challenges,researchers have attempted to leverage sharding technology to partition the blockchain network into multiple subnets that can independently execute transactions.Each subnet can process transactions in parallel.In an ideal scenario,each transaction only accesses a single shard,enabling parallel transaction processing,and the performance of the blockchain improves proportionally with the number of shards.However,in practical business scenarios,there are cross-shard transactions that require operations across multiple shards,making it exceedingly difficult to achieve the ideal scenario.Due to the unique characteristics of cross-shard transactions,their execution efficiency directly impacts the overall performance of the sharded system.Therefore,enhancing the execution efficiency of cross-shard transactions has become a critical concern for optimizing the overall performance of the sharding system.Existing cross-shard transaction execution methods based on multi-stage communication fail to meet the demands of modern industries for large-scale systems in terms of both performance and scalability.Additionally,although blockchain can efficiently handle low-conflict workloads,its performance decreases under high-conflict workloads,leading to a significant increase in latency for cross-shard transactions.To address the aforementioned issues,this paper proposes a cross-shard transaction execution method specifically designed for shard-based permissioned blockchains.The method is based on the order lock mechanism and employs one-way communication for executing cross-shard transactions,significantly improving the system’s execution efficiency.Additionally,this execution method equips a conflict-resistant transaction reordering technique.This not only enhances the transaction processing performance of the cross-shard execution method under high-conflict scenarios but also optimizes the efficiency of state transfer during cross-shard transaction execution.In summary,this paper makes the following contributions:(1)A coordinator-free cross-shard transaction execution method is proposed for sharded permissioned blockchain,which enhances the efficiency of cross-shard transaction processing in the sharded system.through one-way communication based on transaction sequence numbers.A low communication overhead strategy is designed for state transfer,ensuring the authenticity of state data transmitted between shards.(2)Proposes an optimized scheme for conflict-resistant cross-shard transaction execution.The scheme combines transaction reordering techniques and cross-shard transaction execution techniques to enhance the efficiency of transaction execution under high-concurrency workloads.Additionally,the scheme optimizes the state transmission during cross-shard transaction execution to further improve system performance.(3)A prototype system integrating the above technologies is implemented and experiments are conducted under different workloads.Experimental results show that the prototype system outperforms systems of other protocolsIn summary,this paper addresses the issues of low efficiency and scalability in crossshard transaction execution for sharded permissioned blockchains.Two approaches are proposed: a coordinator-free cross-shard transaction execution method and a conflictresistant optimization scheme for cross-shard transaction execution.These approaches effectively improve the system’s performance when processing cross-shard transactions,reduce the latency of cross-shard transactions,and enhance system scalability.Finally,the aforementioned techniques are integrated into a real blockchain system,resulting in a high-performance and highly scalable prototype system.Through relevant experiments,the superiority and effectiveness of the proposed optimization approaches in this paper are demonstrated.