"MySQL server is running with the --super-read-only option" Displayed When Setting Up the MySQL+MGR Single-Primary Mode

Symptom

During the setup of MySQL 8.0.18+MGR single-primary mode, the message "The MySQL server is running with the --super-read-only option so it cannot execute this statement" is displayed after alter user 'repl'@'%' IDENTIFIED WITH caching_sha2_password; is executed.

Key Process and Cause Analysis

The read-only mode is set for the primary database. You need to disable the read-only mode.

Conclusion and Solution

1. Disable the read-only mode for the primary database.

   set global read_only=OFF;

2. Run the following command again.

   alter user 'repl'@'%' IDENTIFIED WITH caching_sha2_password;