SQL Statements for Controlling Group Replication Configures the maximum number of consensus instances that a group can execute in parallel. The GROUP_REPLICATION_ADMIN  privilege is required to use this function. Any resulting error as a string. For more information, see Section 18.5.1.3, “Using Group Replication Group Write Consensus” . The following functions enable you to inspect and configure the Group Replication communication protocol version that is used by a replication group. Inspect the Group Replication communication protocol version that is currently in use for a group. This function has no parameters. The oldest MySQL Server version that can join this group and use the group’s communication protocol. Versions from MySQL 5.7.14 allow compression of messages, and versions from MySQL 8.0.16 also allow fragmentation of messages. Note that the group_replication_get_communication_protocol()  function returns the minimum MySQL version that the group supports, which might differ from the version number that was passed to the group_replication_set_communication_protocol()  function, and from the MySQL Server version that is installed on the member where you use the function. If the protocol cannot be inspected because this server instance does not belong to a replication group, an error is returned as a string. • members : Sets the maximum number of consensus instances that a group can execute in parallel. Default value is 10, valid values are integers in the range of 10 to 200. • group_replication_get_communication_protocol() Syntax: Arguments: Return value: Example: 13.4.3.6 Functions to Inspect and Set the Group Replication Communication Protocol Version Syntax: Return value: Example: STRING group_replication_get_communication_protocol() SELECT group_replication_set_write_concurrency( instances ); SELECT group_replication_get_communication_protocol(); +------------------------------------------------+ | group_replication_get_communication_protocol() | +------------------------------------------------+ | 8.0.16 | 2788 STRING group_replication_set_write_concurrency( instances )