Building a 4-Node Pi Cluster
A four-node Pi cluster won't beat a used desktop on raw compute. That's not the point. The point is learning distributed systems on hardware you can physically unplug to simulate failure — chaos engineering with your actual hands.
Shopping list
- 4× Pi 4B (4GB is plenty), PoE+ HATs, and a cheap PoE switch — one cable per node.
- A case with a fan. Thermal throttling makes benchmarks lie.
- SSDs over USB3, not SD cards. K3s etcd writes will murder an SD card in months.
Software
K3s, not full Kubernetes. One curl-pipe on the server node, one on each agent, and you have a real cluster. Then break it: pull a node's power mid-deploy and watch the pods reschedule. That lesson is the entire tuition.