Modelling and analysing the reliability for microservice-based cloud application based on predicate Petri net

Microservice design is a new paradigm of cloud application development. Different from monolithic design, microservice enjoys merits of fine-grained and loosely coupled services, and it is becoming more and more popular. The application developed with microservice has a good advantage in independent development and flexible deployment, especially for complex distributed systems. However, there is a big gap between the reliability requirements and microservice-based cloud applications. This article proposes a reliability model of microservice-based cloud application by using predicate Petri net. First, a microservice reliability requirement is given, some basic concepts of predicate Petri net are defined with syntax and semantics. Second, a microservice reliability strategy is proposed, which uses microservice instances and circuit breaker to improve the reliability of the system. Based on the constructed microservice reliability model, the correctness of predicate Petri net modelling and the effectiveness of the strategies are proven theoretically. Finally, an example is given to illustrate the establishment and analysis process of the model, and several groups of experiments are carried out to verify the effectiveness and feasibility of the method. Experimental results show that the proposed microservice reliability strategy is effective.