Comparison
Node drainvsSpot interruption
Node drain
you mark the machine unschedulable and evict everything on it politely, so the upgrade takes an hour instead of a page.
The two-step process for taking a node out of service: cordon it so nothing new is scheduled there, then evict what is running so it moves elsewhere. It is the routine operation behind every upgrade, resize and spot reclamation, and it is where disruption budgets, grace periods and shutdown handling are all tested at once. A drain that hangs is nearly always a workload with no other place to go or a budget that cannot be met.
Full entry →Spot interruption
a two-minute warning arrives and everything on that node has to drain, checkpoint and be gone before it is killed.
The provider reclaiming spot capacity, preceded by a short notice. Handling it well is a workload property rather than a platform setting: the node must cordon and drain on the signal, and the workload must shut down cleanly within the window. It is also useful as a permanent, free chaos experiment, since a fleet that handles interruptions gracefully handles node failure gracefully too.
Full entry →