Group Replication Status Variable is changed to match. If the group members have a value set for this system variable, and the joining member does not support the system variable, it cannot join the group. group_replication_view_change_uuid  specifies an alternative UUID to use as the UUID part of the identifier in the GTIDs for view change events generated by the group. The alternative UUID makes these internally generated transactions easy to distinguish from transactions received by the group from clients. This can be useful if your setup allows for failover between groups, and you need to identify and discard transactions that were specific to the backup group. The default value for this system variable is  AUTOMATIC , meaning that the GTIDs for view change events use the group name specified by the group_replication_group_name  system variable, as transactions from clients do. Group members at a release that does not have this system variable are treated as having the value  AUTOMATIC . The alternative UUID must be different from the group name specified by the group_replication_group_name  system variable, and it must be different from the server UUID of any group member. It must also be different from any UUIDs used in the GTIDs that are applied to anonymous transactions on replication channels anywhere in this topology, using the ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS  option of the  CHANGE REPLICATION SOURCE TO statement. This section describes the status variable which provides information about Group Replication. The variable has the following meaning: Shows the primary member’s UUID when the group is operating in single-primary mode. If the group is operating in multi-primary mode, shows an empty string. The  group_replication_primary_member  status variable has been deprecated and is scheduled to be removed in a future version. See Finding the Primary. This section provides answers to frequently asked questions. A group can consist of maximum 9 servers. Attempting to add another server to a group with 9 members causes the request to join to be refused. This limit has been identified from testing and benchmarking as a safe boundary where the group performs reliably on a stable local area network. Servers in a group connect to the other servers in the group by opening a peer-to-peer TCP connection. These connections are only used for internal communication and message passing between servers in the group. This address is configured by the  group_replication_local_address  variable. 3834 Group Replication Status Variable Warning 18.10 Frequently Asked Questions What is the maximum number of MySQL servers in a group? How are servers in a group connected? • group_replication_primary_member