https://cossth.com Security-reviewed engineering notes about Kubernetes, observability, storage, databases, and reliable operations. en-us Wed, 30 Sep 2026 05:30:00 GMT https://cossth.com/blog/retiring-24-7-nginx-pods-object-storage-gitops https://cossth.com/blog/retiring-24-7-nginx-pods-object-storage-gitops Wed, 30 Sep 2026 05:30:00 GMT shubham@cossth.com (Shubham Sharma) Kubernetes GitOps Object Storage Platform Engineering SRE Static frontends do not always need a permanent web-server pod. This case study explains how we replaced always-on Nginx workloads with short-lived synchronization jobs, versioned object storage, and a shared read-only delivery gateway while preserving GitOps deployment and rollback safety. https://cossth.com/blog/the-328-percent-memory-mirage-kubernetes-ghost-limits https://cossth.com/blog/the-328-percent-memory-mirage-kubernetes-ghost-limits Sun, 27 Sep 2026 00:00:00 GMT shubham@cossth.com (Shubham Sharma) Kubernetes SRE Observability Prometheus Capacity Planning Linux Kernel A telemetry review found that configured Kubernetes memory ceilings exceeded available capacity by more than threefold. This anonymized case study explains how to identify policy drift, stage safer changes, and verify the outcome without exposing operational details. https://cossth.com/blog/postmortem-control-plane-memory-exhaustion-iscsi-failover https://cossth.com/blog/postmortem-control-plane-memory-exhaustion-iscsi-failover Fri, 25 Sep 2026 00:00:00 GMT shubham@cossth.com (Shubham Sharma) Kubernetes SRE Storage Linux Kernel Postmortem A blameless, anonymized review of how control-plane memory pressure, storage latency, and health-check failures combined into an availability incident—and how verified monitoring changes improved response. https://cossth.com/blog/zero-overhead-distributed-tracing-ebpf-vs-otel-sdk https://cossth.com/blog/zero-overhead-distributed-tracing-ebpf-vs-otel-sdk Sat, 12 Sep 2026 00:00:00 GMT shubham@cossth.com (Shubham Sharma) Observability eBPF OpenTelemetry Go A security-safe, qualitative comparison of kernel-assisted auto-instrumentation and in-process OpenTelemetry SDKs, covering overhead, semantic context, privacy, and hybrid design. https://cossth.com/blog/postmortem-ebpf-socket-filter-leak-tcp-resets https://cossth.com/blog/postmortem-ebpf-socket-filter-leak-tcp-resets Fri, 14 Aug 2026 00:00:00 GMT shubham@cossth.com (Shubham Sharma) Kernel eBPF Kubernetes SRE An educational case study and systems engineering reference on kernel resource accounting in Linux telemetry: why user-space process restarts fail to reclaim kernel-resident BPF state, and how to verify lifecycle invariants. https://cossth.com/blog/migrating-cnpg-to-single-replica-longhorn https://cossth.com/blog/migrating-cnpg-to-single-replica-longhorn Mon, 06 Jul 2026 00:00:00 GMT shubham@cossth.com (Shubham Sharma) Storage Kubernetes Database SRE An anonymized case study on assigning recovery responsibility between database and storage layers, reducing duplicated write work without presenting the design as a universal rule. https://cossth.com/blog/adr-009-immutable-talos-linux-vs-ubuntu-baremetal https://cossth.com/blog/adr-009-immutable-talos-linux-vs-ubuntu-baremetal Sat, 14 Mar 2026 00:00:00 GMT shubham@cossth.com (Shubham Sharma) Talos Architecture Kubernetes Linux An anonymized architecture decision explaining why a declarative, immutable Kubernetes operating system reduced configuration drift while introducing a stricter operational model.