Amoeba: QoS-Awareness and Reduced Resource Usage of Microservices with Serverless Computing

While microservices that have stringent Quality-of-Service constraints are deployed in the Clouds, the long-term rented infrastructures that host the microservices are underutilized except peak hours due to the diurnal load pattern. It is resource efficient for Cloud vendors and cost efficient for service maintainers to deploy the microservices in the long-term infrastructure at high load and in the serverless computing platform at low load. However, prior work fails to take advantage of the opportunity, because the contention between microservices on the serverless platform seriously affects their response latencies. Our investigation shows that the load of a microservice, the shared resource contentions on the serverless platform, and its sensitivities to the contention together affect the response latency of the microservice on the platform. To this end, we propose Amoeba, a runtime system that dynamically switches the deployment of a microservice. Amoeba is comprised of a contention-aware deployment controller, a hybrid execution engine, and a multi-resource contention monitor. The deployment controller predicts the tail latency of a microservice based on its load and the contention on the serverless platform, and determines the appropriate deployment of the microservice. The hybrid execution engine enables the quick switch of the two deploy modes. The contention monitor periodically quantifies the contention on multiple types of shared resources. Experimental results show that Amoeba is able to significantly reduce up to 72.9% of CPU usage and up to 84.9% of memory usage compared with the traditional pure IaaS-based deployment, while ensuring the required latency target.