Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value ON This system variable is a group-wide configuration setting. It must have the same value on all group members, cannot be changed while Group Replication is running, and requires a full reboot of the group (a bootstrap by a server with  group_replication_bootstrap_group=ON ) in order for the value change to take effect. If the group has a value set for this system variable, and a joining member has a different value set for the system variable, the joining member cannot join the group until the value 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. From MySQL 8.0.16, you can use the  group_replication_switch_to_single_primary_mode() and  group_replication_switch_to_multi_primary_mode()  functions to change the value of this system variable while the group is still running. For more information, see Section 18.5.1.2, “Changing a Group’s Mode” . group_replication_single_primary_mode  instructs the group to automatically pick a single server to be the one that handles read/write workload. This server is the PRIMARY and all others are SECONDARIES. The value of this system variable can be changed while Group Replication is running, but the change only takes effect after you stop and restart Group Replication on the group member. group_replication_ssl_mode  sets the security state of group communication connections between Group Replication members. The possible values are as follows: DISABLED Establish an unencrypted connection (the default). REQUIRED Establish a secure connection if the server supports secure connections. 3830 Command-Line Format --group-replication-ssl-mode=value System Variable group_replication_ssl_mode Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Enumeration Default Value DISABLED Valid Values DISABLED REQUIRED VERIFY_CA VERIFY_IDENTITY • group_replication_ssl_mode Group Replication System Variables