When Your Homelab Grows Up: How SQLite Took Down My k3s Control Plane

Originally published at wostal.eu.

TL;DR: My Hetzner k3s lab quietly became a platform. Dozens of operators with leader-election leases hammered the default datastore — SQLite via kine — until compaction entered a death-spiral: 1.36M rows, a 13.8 GB WAL that wouldn't checkpoint, CPU pinned at 99%, load average 79 on 8 cores. I stopped the bleeding by truncating the WAL, then migrated the control plane to embedded etcd (7.5 GB SQLite → 313 MB etcd, load 79 → 5). This is the full postmortem — and the lessons.

This is a war story, not a tutorial. It's about the moment a homelab stops being a homelab and starts behaving like production — without ever announcing it. The cluster in question, homelab, is the Hetzner k3s setup I wrote about previously. It started small. It did not stay small.

In this post I'll cover:

How an overgrown lab broke the default datastore — the kine/SQLite compaction death-spiral