SQL Statements for Controlling Group Replication 13.4.3.1 START GROUP_REPLICATION Statement 13.4.3.2 STOP GROUP_REPLICATION Statement 2785 Stops Group Replication. This statement requires the  GROUP_REPLICATION_ADMIN  privilege (or the deprecated  SUPER  privilege). As soon as you issue  STOP GROUP_REPLICATION  the member is set to  super_read_only=ON , which ensures that no writes can be made to the member while Group Replication stops. Any other replication channels running on the member are also stopped. Any user credentials that you specified on the  START GROUP_REPLICATION  statement when starting Group User credentials specified on  START GROUP_REPLICATION  take precedence over any user credentials set for the  group_replication_recovery  channel using a  CHANGE REPLICATION SOURCE TO  statement (from MySQL 8.0.23) or  CHANGE MASTER TO  statement (before MySQL 8.0.23). Note that user credentials set using these statements are stored in the replication metadata repositories, and are used when  START GROUP_REPLICATION  is specified without user credentials, including automatic starts if the  group_replication_start_on_boot  system variable is set to  ON . To gain the security benefits of specifying user credentials on  START GROUP_REPLICATION , ensure that  group_replication_start_on_boot  is set to  OFF  (the default is  ON ), and clear any user credentials previously set for the  group_replication_recovery  channel, following the instructions in Section 18.6.3, “Securing Distributed Recovery Connections” . These credentials are used for distributed recovery on the  group_replication_recovery  channel. When you specify user credentials on  START GROUP_REPLICATION , the credentials are saved in memory only, and are removed by a  STOP GROUP_REPLICATION  statement or server shutdown. You must issue a  START GROUP_REPLICATION  statement to provide the credentials again. This method is therefore not compatible with starting Group Replication automatically on server start, as specified by the group_replication_start_on_boot  system variable. Starts group replication. This statement requires the  GROUP_REPLICATION_ADMIN  privilege (or the deprecated  SUPER  privilege). If  super_read_only=ON  is set and the member should join as a primary, super_read_only  is set to  OFF  once Group Replication successfully starts. From MySQL 8.0.21, you can specify user credentials for distributed recovery on the  START GROUP_REPLICATION  statement using the  USER ,  PASSWORD , and  DEFAULT_AUTH  options, as follows: START GROUP_REPLICATION [USER=’ user_name ’] [, PASSWORD=’ user_pass ’] [, DEFAULT_AUTH=’ plugin_name ’] STOP GROUP_REPLICATION • USER : The replication user for distributed recovery. For instructions to set up this account, see Section 18.2.1.3, “User Credentials For Distributed Recovery” . You cannot specify an empty or null string, or omit the  USER  option if  PASSWORD  is specified. • PASSWORD : The password for the replication user account. The password cannot be encrypted, but it is masked in the query log. • DEFAULT_AUTH : The name of the authentication plugin used for the replication user account. If you do not specify this option, MySQL native authentication (the  mysql_native_password  plugin) is assumed. This option acts as a hint to the server, and the donor for distributed recovery overrides it if a different plugin is associated with the user account on that server. The authentication plugin used by default when you create user accounts in MySQL 8 is the caching SHA-2 authentication plugin ( caching_sha2_password ). See Section 6.2.17, “Pluggable Authentication”  for more information on authentication plugins.