Create update groups for worker machines

Available since 2.27.0 (17.2.0 and 16.2.0)

The use of update groups provides enhanced control over update of worker machines by allowing granular concurrency settings for specific machine groups. This feature uses the UpdateGroup object to decouple the concurrency settings from the global cluster level, providing flexibility based on the workload characteristics of different machine sets.

The UpdateGroup objects are processed sequentially based on their indexes. Update groups with the same indexes are processed concurrently.


The update order of a machine within the same group is determined by the upgrade index of a specific machine. For details, see Change the upgrade order of a machine or machine pool.

The maxWorkerUpgradeCount parameter of the Cluster object is inherited by the default update group. Changing maxWorkerUpgradeCount leads to changing the concurrentUpdates parameter of the default update group.


The maxWorkerUpgradeCount parameter of the Cluster object is deprecated and will be removed in one of the following Container Cloud releases. You can still use this parameter to change the concurrentUpdates value of the default update group. However, Mirantis recommends changing this value directly in the UpdateGroup object.

Default update group

The default update group is automatically created during initial cluster creation with the following settings:

  • Name: <cluster-name>-default

  • Index: 1

  • Concurrent updates: inherited from the maxWorkerUpgradeCount parameter set in the Cluster object.


On existing clusters created before 2.27.0, the default update group is created after upgrade of the Container Cloud release to 2.27.0 (Cluster release 16.2.0) on the management cluster.

Example of the default update group:

kind: UpdateGroup
  name: example-cluster-default
  namespace: example-ns
  index: 1
  concurrentUpdates: 1

If you require custom update settings for worker machines, create one or several custom UpdateGroup objects as described below.

Assign a machine to an update group using CLI


All worker machines that are not assigned to any update group are automatically assigned to the default update group.

  1. Create an UpdateGroup object with the required specification. For description of the object fields, see UpdateGroup resource.

  2. Label the machines to associate them with the newly created UpdateGroup object:

    kubectl label machine <machineName><UpdateGroupObjectName>

    To change the update group of a machine, update the label of the machine with the new update group name. Removing this label from a machine automatically assigns such machine to the default update group.


After creation of a custom UpdateGroup object, if you plan to add a new machine that requires a non-default update group, manually add the corresponding label to the machine as described above. Otherwise, the default update group is applied to such machine.


Before removing the UpdateGroup object, reassign all machines to another update group.