I. Introduction
Edge cloud has emerged as a promising platform complementary to cloud systems by provisioning computation resources at the network edge. Owing to the advantage on end user proximity, edge cloud is ideal for many delay-sensitive applications such as self-driving, healthcare, augmented reality, and smart manufacturing. Meanwhile, in comparison with central cloud empowered by large datacenters, edge cloud resources are relatively scarce. Therefore, how to mostly effectively utilize the edge resources has become one of the main research focuses recently. On the other hand, container-based microservices have been advocated as an edge service provision paradigm, due to its lightweight advantages, which offer flexibility and elasticity over conventional virtual machines (VMs) [1]–[3].