7.4.1 Pre-Checking Instance Configuration for InnoDB Cluster Usage

Before creating a production deployment from server instances you need to check that MySQL on each instance is correctly configured. The dba.configureInstance() function does this as part of configuring the instance, but you can optionally use the dba.checkInstanceConfiguration(instance) function . This checks whether the instance satisfies the requirements listed in Section 7.1, “InnoDB Cluster Requirements” without changing any configuration on the instance.

The user which you use to connect to the instance must have suitable privileges, for example as configured at Configuring InnoDB Cluster Administrator Accounts Manually. The following demonstrates issuing this in a running MySQL Shell:

mysql-js> dba.checkInstanceConfiguration('icadmin@ic-1:3306')
Please provide the password for 'icadmin@ic-1:3306': ***
Validating MySQL instance at ic-1:3306 for use in an InnoDB cluster...

This instance reports its own address as ic-1
Clients and other cluster members will communicate with it through this address by default.
If this is not correct, the report_host MySQL system variable should be changed.

Checking whether existing tables comply with Group Replication requirements...
No incompatible tables detected

Checking instance configuration...

Some configuration options need to be fixed:
+--------------------------+---------------+----------------+--------------------------------------------------+
| Variable                 | Current Value | Required Value | Note                                             |
+--------------------------+---------------+----------------+--------------------------------------------------+
| enforce_gtid_consistency | OFF           | ON             | Update read-only variable and restart the server |
| gtid_mode                | OFF           | ON             | Update read-only variable and restart the server |
| server_id                | 1             |                | Update read-only variable and restart the server |
+--------------------------+---------------+----------------+--------------------------------------------------+

Please use the dba.configureInstance() command to repair these issues.

{
    "config_errors": [
        {
            "action": "restart",
            "current": "OFF",
            "option": "enforce_gtid_consistency",
            "required": "ON"
        },
        {
            "action": "restart",
            "current": "OFF",
            "option": "gtid_mode",
            "required": "ON"
        },
        {
            "action": "restart",
            "current": "1",
            "option": "server_id",
            "required": ""
        }
    ],
    "status": "error"
}

Repeat this process for each server instance that you plan to use as part of your cluster. The report generated after running dba.checkInstanceConfiguration() provides information about any configuration changes that will be required to use the instance in an InnoDB Cluster deployment. The action field in the config_error section of the report tells you whether MySQL on the instance requires a restart to detect any change made to the configuration file.