Group Replication System Variables using the  group_replication_message_cache_size  system variable. For more information, see Section 18.7.5, “XCom Cache Management” . If the timeout is exceeded, the suspect member is liable for expulsion immediately after the suspicion times out. If the member is able to resume communications and receives a view where it is expelled, and the member has the  group_replication_autorejoin_tries  system variable set to specify a number of auto-rejoin attempts, it proceeds to make the specified number of attempts to rejoin the group while in super read only mode. If the member does not have any auto-rejoin attempts specified, or if it has exhausted the specified number of attempts, it follows the action specified by the system variable group_replication_exit_state_action . For more information on using the  group_replication_member_expel_timeout  setting, see Section 18.7.6.1, “Expel Timeout” . For alternative mitigation strategies to avoid unnecessary expulsions where this system variable is not available, see Section 18.3.2, “Group Replication Limitations” . • group_replication_member_weight Command-Line Format --group-replication-member-weight=# System Variable group_replication_member_weight Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 50 Minimum Value 0 Maximum Value 100 Unit percentage The value of this system variable can be changed while Group Replication is running, and the change takes effect immediately. The system variable’s current value is read when a failover situation occurs. group_replication_member_weight  specifies a percentage weight that can be assigned to members to influence the chance of the member being elected as primary in the event of failover, for example when the existing primary leaves a single-primary group. Assign numeric weights to members to ensure that specific members are elected, for example during scheduled maintenance of the primary or to ensure certain hardware is prioritized in the event of failover. For a group with members configured as follows: during election of a new primary the members above would be sorted as  member-2 ,  member-3 , member-4 , and  member-1 . This results in  member -2 being chosen as the new primary in the event of failover. For more information, see Section 18.1.3.1, “Single-Primary Mode” . 3819 • member-1 : group_replication_member_weight=30, server_uuid=aaaa • member-2 : group_replication_member_weight=40, server_uuid=bbbb • member-3 : group_replication_member_weight=40, server_uuid=cccc • member-4 : group_replication_member_weight=40, server_uuid=dddd