In this section you can find the migration path when upgrading to a newer version of the MySQL operator.

Regarding how a MySQL cluster is affected, we will try to keep it as follows when upgrading the operator:

• PATCH versions (e.g. v0.3.2 -> v0.3.3 or v0.3.4): no restart for the MySQL cluster
• MINOR versions (e.g. v0.3.2 -> v0.4.0): the MySQL cluster will get restarted
• MAJOR versions (e.g. v0.5.0 -> v1.0.0): the MySQL cluster will get restarted and it may required manual intervention.

v0.2.x upgrade

Here are described the steps that you should follow when migrating from version 0.1.x to 0.2.x of the operator.

This upgrade requires a Kubernetes cluster upgrade because the v0.2.x works only with a Kubernetes version greater or equal to 1.11.

1. Scale the current operator deployment to 0. This won't affect your running databases.
2. Upgrade your cluster control plane to 1.11.
3. Update the installed CRDs: kubectl apply -f https://raw.githubusercontent.com/presslabs/mysql-operator/master/hack/02x-crds.yaml
4. Upgrade the MySQL operator helm upgrade mysql-operator presslabs/mysql-operator
5. Scale up the operator deployment
6. Now you can upgrade your nodes, as well.
7. Enjoy!

v0.3.x upgrade

This version requires at least Kubernetes 1.11. The upgrade should be tried on staging environment first because it's with downtime. It requires the deletion of the statefulset and recreation of it. The reason behind is that we changed the headless service name (which is an immutable statefulset field) to make it smaller that will prevent you from hitting this bug.

The operator should do all the work for you but you have to make sure that you have the latest 0.2.x version of the operator. For a smooth upgrade, it's recommended to have clusters with only one node or the master node to be node 0. Doing so will prevent the operator to wait for a failover.

This release drop support for emptyDir volume source.