The script for stateful set compares the spec and status with wrong information.

It currently check for status.updatedReplicas = spec.replicas and also status.currentReplicas = spec.replicas and this does not work properly as soon as the revision of the stateful changes.

For instance if you deploy mariadb cluster from scratch the value of currentReplicas and updatedReplicas will be the same and equal to the spec.replicas

Here's an example with one replica

status:
  collisionCount: 0
  currentReplicas: 1
  currentRevision: onap-mariadb-galera-59f77768cf
  observedGeneration: 1
  readyReplicas: 1
  replicas: 1
  updateRevision: onap-mariadb-galera-59f77768cf
  updatedReplicas: 1

Now if i change stateful set definition (change the livenessProbe value for instance). The status becomes

status:
  collisionCount: 0
  currentReplicas: 1
  currentRevision: onap-mariadb-galera-59f77768cf
  observedGeneration: 2
  readyReplicas: 1
  replicas: 1
  updateRevision: onap-mariadb-galera-b8bfbd7cd

As you can see the value of currentRevision and updateRevision changed, i did not delete the pod yet.

If i delete the pod and let it restart the status becomes

status:
  collisionCount: 0
  currentRevision: onap-mariadb-galera-59f77768cf
  observedGeneration: 2
  readyReplicas: 1
  replicas: 1
  updateRevision: onap-mariadb-galera-b8bfbd7cd
  updatedReplicas: 1

Now the value of currentReplicas is no longer there because there are no pods that were created with the stateful set revision `currentRevision` but only contains one pod created with the revision `updatedRevision`. 

This is causing all pods depending on mariadb to no longer start because the script always returns false since currentReplicas is not equal to spec.replicas.

The logic should be fairly easy to fix by only looking at readyReplicas since this is ultimately what we want, wait for the number of ready pods to be equals to spec.replicas.