Update Strategyedit

The operator takes a Pod down to restart and applies a new configuration value. All Pods are restarted in reverse ordinal order.

Default behavioredit

When updateStrategy is not present in the specification, it defaults to the following:

spec:
  updateStrategy:
    type: "RollingUpdate" 
    rollingUpdate:
      partition: 0        
      maxUnavailable: 1   

The RollingUpdate strategy will update Pods one by one in reverse ordinal order.

This means that all the Pods from ordinal Replicas-1 to partition are updated . You can split the update into partitions to perform canary rollout.

This ensures that the cluster has no more than one unavailable Pod at any given point in time.

OnDeleteedit

spec:
  updateStrategy:
    type: "OnDelete"

OnDelete strategy does not automatically update Pods when a modification is made. You need to restart Pods yourself.