This article explains how the kubectl command interacts with the Kubernetes control plane, detailing one‑way HTTPS requests and two‑way WebSocket communications, and walks through the full execution flow of a kubectl exec command across kube‑api‑server, kubelet, and the CRI runtime.
This article details a real-world Kubernetes control‑plane outage where kube‑apiserver repeatedly OOM‑killed, explores cluster metrics, logs, heap and goroutine profiles, hypothesizes root causes such as etcd latency and DeleteCollection memory leaks, and offers step‑by‑step troubleshooting and prevention guidance.
This article details a real‑world Kubernetes control‑plane outage where kube‑apiserver repeatedly OOM‑killed, examines cluster metrics, logs, heap and goroutine profiles, explores root‑cause hypotheses such as etcd latency and DeleteCollection memory leaks, and offers practical prevention steps.
On September 10 2021, a Kubernetes cluster experienced intermittent kubectl hangs caused by kube-apiserver OOM kills, leading to cascading control-plane failures; this article details the environment, observed metrics, log analysis, code inspection of DeleteCollection, and provides troubleshooting steps to prevent similar incidents.
This article analyzes a September 2021 incident where a Kubernetes cluster’s kube-apiserver repeatedly OOM-killed, causing kubectl hangs, by examining cluster specs, monitoring data, logs, heap and goroutine profiles, and the DeleteCollection implementation, ultimately offering troubleshooting steps and preventive measures for control-plane stability.
The article offers a clear, beginner‑friendly overview of Kubernetes architecture—including master‑slave roles, key components like etcd and kube‑apiserver, the registration‑watch workflow, and custom controllers such as lb‑controller and log‑controller—while inviting readers to share feedback and explore deeper implementation details.
