"binlog checksum should be NONE for Group Replication" Displayed During MGR Installation When Setting Up the MySQL+MGR Single-Primary Mode

Symptom

When the install PLUGIN group_replication SONAME 'group_replication.so'; statement is executed to install the MySQL Group Replication (MGR) plugin during the setup of MySQL 8.0.18+MGR single-primary mode, the messages "binlog checksum should be NONE for Group Replication" and "Unable to start Group Replication on boot" are displayed.

Key Process and Cause Analysis

The MGR plugin does not support binlog_checksum in MySQL versions earlier than 5.7. If binlog_checksum is set to a value other than none, the MGR plugin cannot work properly. Therefore, you need to set binlog_checksum to none. In MySQL 5.7 and later versions, the MGR plugin supports binlog_checksum.

Conclusion and Solution

1. Set binlog_checksum to none in the configuration file. If this parameter does not exist, add the following content to the [mysqld] field. This setting takes effect after the database is restarted.

   binlog_checksum=none

2. Restart the database.

   sudo service mysql restart

3. Install the MGR plugin.

   install PLUGIN group_replication SONAME 'group_replication.so';