Rollback Windows

Important

Available for blue-green and canary rollouts since v1.4

By default, when an older Rollout manifest is re-applied, the controller treats it the same as a spec change, and will execute the full list of steps, and perform analysis too. There are two exceptions to this rule: 1. the controller detects if it is moving back to a blue-green ReplicaSet which exists and is still scaled up (within its scaleDownDelay) 2. the controller detects it is moving back to the canary's "stable" ReplicaSet, and the upgrade had not yet completed.

It is often undesirable to re-run analysis and steps for a rollout, when the desired behavior is to rollback as soon as possible. To help with this, a rollback window feature allows users to indicate that the promotion to the ReplicaSet within the window will skip all steps.

Example:

spec:
  rollbackWindow:
    revisions: 3

  revisionHistoryLimit: 5

Assume a linear revision history: 1, 2, 3, 4, 5 (current). A rollback from revision 5 back to 4 or 3 will fall within the window, so it will be fast tracked.