A microservice based generic consensus engine for BaaS

Blockchain-as-a-Service (BaaS) has gradually serve as an infrastructure, providing underlying blockchain services for the rapid deployment and transaction on-chain of large-scale enterprise application scenarios. By hosting different blockchains in its underlying structure layers, BaaS platform satisfies the requirements of consensus algorithms in different scenarios, and still uses its own consensus algorithms in different blockchains, which has limited scalability and is difficult to satisfy the requirements of future applications. To deal with such problems, MGCE, a microservice based generic consensus engine for BaaS is proposed in this paper. It is a functional framework based on microservices architecture which can load the appropriate consensus algorithm and perform the consensus process of transactions for blockchain nodes according the different scenarios. The engine is composed of Consensus Node Group, Consensus Management and four functional modules, namely Consensus Network, Transactions Pool, Consensus Protocol and Consensus Outcome. For microservice purpose, each functional module is deployed into a independently project, running in its own process, which is easy to modify and test, and interacts with other modules through the http APIs to complete the consensus process together. To test the function and performance of this engine, three common consensus algorithms have been implemented including Raft, BFT-SMART and PoW. Through experiments, it is proved that this engine could realize the loading and use of different consensus algorithms. Through the performance comparison between using the engine and with the direct use of each consensus algorithm, the results show that the overhead introducing the engine is acceptable. Through the operation result of three algorithms in different projects, the design of engine architecture could satisfy the microservice objective.