eBPF-Based Observability: Kernel-Level Tracing For Production Systems

Abstract

Understanding what a busy server is really doing has always meant a trade-off. Lightweight sampling misses rare events, while heavyweight tracing perturbs the very system it measures. The extended Berkeley Packet Filter, eBPF, breaks that trade-off by letting operators run small, verified programs inside the Linux kernel, attached to function entry points, network paths, and system calls, without patching the kernel or loading a module. This paper explains how eBPF works, why its verifier and just-in-time compiler make in-kernel code safe enough to run in production, and how the technology underpins a new generation of observability and security tools such as bpftrace, Cilium, and Falco. We walk through the attachment points that matter for monitoring, the map and ring-buffer mechanisms that carry data to user space, and the performance profile that lets eBPF instrument hot paths at single-digit overhead. Reported measurements show kernel-level tracing adding under two percent CPU cost where conventional ptrace-based tools impose an order of magnitude more. We also note the limits: kernel-version dependence, verifier constraints, and the portability work still in progress.