Enforcing Application-Layer Policies in eBPF

Abstract

Service meshes have recently emerged as the de-facto standard for deploying microservices. Conceptually, they provide a uniform abstraction for inter-process communication (IPC) between services by implementing common networking mechanisms---such as encryption, routing, and load balancing---and by allowing these mechanisms to be configured and composed through high-level policies. Supporting these policies, however, comes with a significant performance cost, since service meshes interpose proxies (``sidecars'') on the data path between every service. This paper presents Beeline, a fast path for service meshes which can enforce the vast majority of application-layer policies seen in the wild directly in kernel space. Given high-level policies, Beeline automatically synthesizes an eBPF-based data plane which enforces them in the kernel. Beeline accelerates existing microservices without any code modification, and transparently falls back to existing service proxies (the slow path) for the few unsupported policies. We fully implemented Beeline, with support for both TLS and HTTP/2. Compared to state-of-the-art service meshes, Beeline reduces the median request latency of realistic applications by up to $6\times$ while sustaining $3\times$ more throughput.