Drain Node

Steadybit agents and extensions are excluded from the drain
kubectl parameter force is used to continue even if there are pods that do not declare a controller
kubectl parameter ignore-daemonsets is used to ignore daemonsets
kubectl parameter delete-emptydir-data is used to delete local data of pods using emptyDir

Use Cases

Check your application failover when a node is drained
Check if new nodes are created by your autoscaler (in combination with node count check)

Parameters

Parameter	Description	Default
Duration	How long should the node keep drained / cordoned?	180s

Rollback

A drained node will be automatically uncorden after the given duration or in case of an error to rollback the effect.

Useful Templates

See all

Draining a node should reschedule pods quickly

When draining a node, Kubernetes should reschedule running pods on other nodes without hiccups to ease, e.g., node maintenance.

Motivation

Draining a node may be necessary for, e.g., maintenance of a node. If that happens, Kubernetes should be able to reschedule the pods running on that node within the expected time and without user-noticeable failures.

Structure

For the entire duration of the experiment, a user-facing endpoint should work within expected success rates. At the beginning of the experiment, all pods should be ready to accept traffic. As soon as the node is drained, Kubernetes will evict the pods, but we still expect the pod's redundancy to be able to serve the user-facing endpoint. Eventually, after 120 seconds, all pods should be rescheduled and ready again to recover after the maintenance.