When a member joins the group, distributed recovery is carried out using a combination of a remote cloning operation, if available and appropriate, and an asynchronous replication connection. For a full description of distributed recovery, see Section 18.4.3, “Distributed Recovery”.

The connection that an existing member offers to a joining member for distributed recovery is not the same connection that is used by Group Replication for communication between online members of the group. Up to MySQL 8.0.20, group members offer their standard SQL client connection to joining members for distributed recovery, as specified by MySQL Server's hostname and port system variables. From MySQL 8.0.21, group members may advertise an alternative list of distributed recovery endpoints as dedicated client connections for joining members. For more details, see Section 18.4.3.1, “Connections for Distributed Recovery”.

To secure distributed recovery connections in the group, ensure that user credentials for the replication user are properly secured, and use SSL for distributed recovery connections if possible.