What Blocks My Blockchain’s Throughput? Developing a Generalizable Approach for Identifying Bottlenecks in Permissioned Blockchains

Permissioned blockchains have been proposed for various use cases where a certain degree of decentralization is necessary yet enterprise~IT requirements must be met. However, their throughput remains considerably lower than that of established centralized systems. Previous studies that address permissioned blockchains' performance remain blockchain-specific, lacking a generalizable approach for locating and understanding bottlenecks. This paper presents a unified, graphical method for identifying bottlenecks in permissioned blockchains. We augment the DLPS -- an open-source benchmarking tool -- with graphical evaluation functionalities and use them to identify performance bottlenecks of Hyperledger Fabric and Quorum, two widely used permissioned blockchains with distinct architectural designs. Our work provides researchers and practitioners with a toolkit, guidelines on blockchain performance data analytics, and insights that assist with the bottleneck identification and improvement of permissioned blockchains.