Karpenter can rotate your nodes for three reasons: they're underutilized, they're empty, or the AMI has drifted from what you specified.

You can set a disruption budget for each reason to control how many nodes rotate at once. But here's the catch: if you only set budgets for two reasons and skip the third, Karpenter doesn't disable it. It silently applies a default 10% budget to any reason you didn't mention.

Adhi Sutandi's team found this the hard way — drift events fired during maintenance windows they thought were locked down. The fix? Set a single budget of one node with no reason qualifier, so it applies to everything.



New episode out now: https://ku.bz/XyVfsSQPr