Sidecars on the Central Lane: Impact of Network Proxies on Microservices

Cloud applications are moving away from monolithic model towards loosely-coupled microservices designs. Service meshes are widely used for implementing microservices applications mainly because they provide a modular architecture for modern applications by separating operational features from application business logic. Sidecar proxies in service meshes enable this modularity by applying security, networking, and monitoring policies on the traffic to and from services. To implement these policies, sidecars often execute complex chains of logic that vary across associated applications and end up unevenly impacting the performance of the overall application. Lack of understanding of how the sidecars impact the performance of microservice-based applications stands in the way of building performant and resource-efficient applications. To this end, we bring sidecar proxies in focus and argue that we need to deeply study their impact on the system performance and resource utilization. We identify and describe challenges in characterizing sidecars, namely the need for microarchitectural metrics and comprehensive methodologies, and discuss research directions where such characterization will help in building efficient service mesh infrastructure for microservice applications.