World K5: Lunch Rush

PodDisruptionBudgets

You will learn: how to keep enough trays serving while you empty a stall.

Checked with Kubernetes 1.37 on 31 Oct 2026

The problem

Tonight you fix stall dev-worker. Two of your three shop trays sit there. If both leave at once, one tray serves the whole queue. How do you stop that?

Watch

You are here: cluster kind-dev namespace default

~/shop $ kubectl create pdb shop --selector=app=shop --min-available=2poddisruptionbudget.policy/shop created~/shop $ kubectl get pdb shopNAME   MIN AVAILABLE   MAX UNAVAILABLE   ALLOWED DISRUPTIONS   AGEshop   2               N/A               1                     0s

That rule is a (PDB). --min-available=2 keeps 2 trays up. With 3 ready, ALLOWED DISRUPTIONS is 1: one may leave at a time.

Try it

Build that command yourself. Each piece shows what it means.

Tap the pieces in the right order.

…

Try it

Now empty stall dev-worker. The danger badge shows: a drain moves trays. Watch the budget make one tray wait its turn.

kubectl drain dev-worker --ignore-daemonsets

You are here: cluster kind-dev namespace default

dev-control-planeOpenManager

No trays here.

dev-workerOpen

shop·7tl6k
shop·swpd9

dev-worker2Open

shop·frd8c

Time: +0s (sped up)

Check

The drain printed: Cannot evict pod as it would violate the pod's disruption budget. What does it mean?

Check

A PDB only slows down planned moves. Sort each event.

Drag a card into a box. Or tap the card, then tap the box.

You did it!

You can now keep the shop serving while you empty a stall.

Go deeper (optional)

Use --max-unavailable instead to say how many may be down. Careful: a budget that allows 0 disruptions blocks every drain forever. After the work, kubectl uncordon dev-worker opens the stall again.

Real rep (optional): on kind, make a PDB. Then drain a worker and read each line.