SHOWAR: Right-sizing and efficient scheduling of microservices

Abstract

Microservices architecture have been widely adopted in designing distributed cloud applications where the application is decoupled into multiple small components (i.e. "microservices"). One of the challenges in deploying microservices is finding the optimal amount of resources (i.e. size) and the number of instances (i.e. replicas) for each microservice in order to maintain a good performance as well as prevent resource wastage and under-utilization which is not cost-effective. This paper presents SHOWAR, a framework that configures the resources by determining the number of replicas (horizontal scaling) and the amount of CPU and Memory for each microservice (vertical scaling). For vertical scaling, SHOWAR uses empirical variance in the historical resource usage to find the optimal size and mitigate resource wastage. For horizontal scaling, SHOWAR uses basic ideas from control theory along with kernel level performance metrics. Additionally, once the size for each microservice is found, SHOWAR bridges the gap between optimal resource allocation and scheduling by generating affinity rules (i.e. hints) for the scheduler to further improve the performance. Our experiments, using a variety of microservice applications and real-world workloads, show that, compared to the state-of-the-art autoscaling and scheduling systems, SHOWAR on average improves the resource allocation by up to 22% while improving the 99th percentile end-to-end user request latency by 20%.