Auto-upgrade scheduled maintenance for AKS
By: Date: 15/09/2023 Categories: azure Tags:

The AKS releases are referred to as AKS initiated maintenance. These releases are your clusters’ weekly rounds of bug fixes, feature updates, and component upgrades.

The kinds of routine maintenance that you carry out are cluster auto-upgrades and Node OS automatic security updates.

Prior to starting

  1. There are currently three available maintenance schedule configuration types: defaultaksManagedAutoUpgradeScheduleaksManagedNodeOSUpgradeSchedule:
  2. Assumes that you already have an AKS cluster in place. If you don’t have an AKS cluster on creating an enterprise-scale AKS, see Plan your AKS design.

Setting up a time for maintenance

To create a maintenance window, you can use the az aks maintenanceconfiguration add command using the --name value defaultaksManagedAutoUpgradeSchedule, or aksManagedNodeOSUpgradeSchedule. The name value should reflect the desired configuration type. Using any other name prevents your maintenance window from running.

Knowing the different kinds of schedules

There are currently four available schedule types: DailyWeeklyAbsoluteMonthly, and RelativeMonthly.

These schedule types are only applicable to aksManagedClusterAutoUpgradeSchedule and aksManagedNodeOSUpgradeSchedule configurations. Daily schedules are only applicable to aksManagedNodeOSUpgradeSchedule types.

Daily schedule

Daily schedule may look like “every three days”:

"schedule": {
    "daily": {
        "intervalDays": 3

Weekly schedule
A Weekly schedule may look like "every two weeks on Friday":
"schedule": {
    "weekly": {
        "intervalWeeks": 2,
        "dayOfWeek": "Friday"

AbsoluteMonthly schedule
An AbsoluteMonthly schedule may look like "every three months, on the first day of the month":
"schedule": {
    "absoluteMonthly": {
        "intervalMonths": 3,
        "dayOfMonth": 1

RelativeMonthly schedule
A RelativeMonthly schedule may look like "every two months, on the last Monday":
"schedule": {
    "relativeMonthly": {
        "intervalMonths": 2,
        "dayOfWeek": "Monday",
        "weekIndex": "Last"

Valid values for weekIndex are First, Second, Third, Fourth, and Last.

Points to remember
Use of Planned Maintenance is subject to the following limitations:

  • AKS reserves the right to break these windows for unplanned, reactive maintenance operations that are urgent or critical. These maintenance operations may even run during the notAllowedTime or notAllowedDates periods defined in your configuration.
  • Maintenance tasks are completed with the utmost care and are not assured to be completed within the allotted time frame.

Refer- Planned Maintenance AKS cluster