Where’s All My Memory Gone? Mapping K8s Memory Metrics To Physical Resources - Mahé Tardy
Mahé Tardy
KubeCon + CloudNativeCon Europe 2025 · Session
Mahé Tardy, a software engineer at Isovalent (Cisco) working on the eBPF-based runtime security project **Tetragon** (part of **Cilium**), delivered a highly informative talk at KubeCon EU addressing a common point of confusion for Kubernetes operators: understanding memory metrics. Specifically, the presentation dives deep into the ubiquitous `container_memory_working_set_bytes` metric, which often appears on Kubernetes dashboards but whose exact meaning and underlying computation remain opaque to many. The talk demystifies this metric by tracing its journey from a **Grafana** dashboard back to its origins within the Linux kernel's **cgroups** subsystem.
AI review
This talk cuts through the typical Kubernetes metrics fog, providing a brutally honest and technically rigorous dissection of `container_memory_working_set_bytes`. Tardy doesn't just show you a graph; she rips apart the abstraction layers, tracing this critical metric from Grafana dashboards all the way down to its cgroup v1/v2 kernel origins. This isn't marketing fluff; it's essential, actionable knowledge for anyone tired of playing guessing games with OOM kills and capacity planning. It's a masterclass in understanding what your systems are *actually* doing.