"more executed transactions than those present in the group" Displayed During Transaction Submission When Setting Up the MySQL+MGR Single-Primary Mode

Symptom

During the setup of MySQL 8.0.18+MGR single-primary mode, the message "This member has more executed transactions than those present in the group" is displayed after the START GROUP_REPLICATION; statement is executed.

Key Process and Cause Analysis

A possible cause is that data is not synchronized.

Conclusion and Solution

1. Reset the master service and query the master status. The master status is restored.

   reset master;
   show master status\G

2. Run the following statement to start the MGR plugin:

   START GROUP_REPLICATION;