21.3.2 Upgrading InnoDB cluster Metadata

As AdminAPI evolves, some releases might require you to upgrade the metadata of existing clusters to ensure they are compatible with newer versions of MySQL Shell. For example, the addition of InnoDB ReplicaSet in version 8.0.19 means that the metadata schema has been upgraded to version 2.0. Regardless of whether you plan to use InnoDB ReplicaSet or not, to use MySQL Shell 8.0.19 or later with a cluster deployed using an earlier version of MySQL Shell, you must upgrade the metadata of your cluster.

This dba.upgradeMetadata() operation compares the version of the metadata schema found on the cluster MySQL Shell is currently connected to with the version of the metadata schema supported by this MySQL Shell version. If the installed metadata version is lower, an upgrade process is started. The dba.upgradeMetadata() operation then upgrades any automatically created MySQL Router users to have the correct privileges. Manually created MySQL Router users with a name not starting with mysql_router_ are not automatically upgraded. This is an important step in upgrading your cluster, only then can the MySQL Router application be upgraded. To get information on which of the MySQL Router instances registered with a cluster require the metadata upgrade, issue:

cluster.listRouters({'onlyUpgradeRequired':'true'})
{
    "clusterName": "mycluster", 
    "routers": {
        "example.com::": {
            "hostname": "example.com", 
            "lastCheckIn": "2019-11-26 10:10:37", 
            "roPort": 6447, 
            "roXPort": 64470, 
            "rwPort": 6446, 
            "rwXPort": 64460, 
            "version": "8.0.18"
        }
    }
}

To upgrade a cluster's metadata, connect MySQL Shell's global session to your cluster and use the dba.upgradeMetadata() operation to upgrade the cluster's metadata to the new metadata. For example:

mysql-js> \connect user@example.com:3306

mysql-js> dba.upgradeMetadata()
InnoDB Cluster Metadata Upgrade

The cluster you are connected to is using an outdated metadata schema version
1.0.1 and needs to be upgraded to 2.0.0.

Without doing this upgrade, no AdminAPI calls except read only operations will
be allowed.

The grants for the MySQL Router accounts that were created automatically when
bootstrapping need to be updated to match the new metadata version's
requirements.
Updating router accounts...
NOTE: 2 router accounts have been updated.

Upgrading metadata at 'example.com:3306' from version 1.0.1 to version 2.0.0.
Creating backup of the metadata schema...
Step 1 of 1: upgrading from 1.0.1 to 2.0.0...
Removing metadata backup...
Upgrade process successfully finished, metadata schema is now on version 2.0.0

If you encounter an error related to the clusterAdmin user missing privileges, follow the instructions for granting the correct privileges.