Failed to Start MGR on the Primary Node

Symptom

During the setup of MySQL 8.0.18+MGR single-primary mode, MGR failed to be started on the primary node. After START GROUP_REPLICATION; is executed, "Error on opening a connection to 192.168.102.175:33061 on local port: 33061" is displayed.

Key Process and Cause Analysis

When starting group replication for the first time, set group_replication_bootstrap_group to ON.

Conclusion and Solution

1. Run the following statement on the primary node to enable the boot group mode in MGR and set group_replication_bootstrap_group to ON:

   SET GLOBAL group_replication_bootstrap_group=ON;

2. Run the following statement to start MGR:

   START GROUP_REPLICATION;

3. Restore the setting of group_replication_bootstrap_group to OFF.

   SET GLOBAL group_replication_bootstrap_group=OFF;