Responses to Failure Detection and Network Partitioning variable. After this, manual intervention is needed to bring the member back into the group. Using the auto- rejoin feature is appropriate if you can tolerate the possibility of stale reads and want to minimize the need for manual intervention, especially where transient network issues fairly often result in the expulsion of members. With auto-rejoin, when the member’s expulsion or unreachable majority timeout is reached, it makes an attempt to rejoin (using the current plugin option values), then continues to make further auto-rejoin attempts up to the specified number of tries. After an unsuccessful auto-rejoin attempt, the member waits 5 minutes before the next try. The auto-rejoin attempts and the time between them are called the auto-rejoin procedure. If the specified number of tries is exhausted without the member rejoining or being stopped, the member proceeds to the action specified by the  group_replication_exit_state_action  system variable. During and between auto-rejoin attempts, a member remains in super read only mode and displays an  ERROR  state on its view of the replication group. During this time, the member does not accept writes. However, reads can still be made on the member, with an increasing likelihood of stale reads over time. If you do want to intervene to take the member offline during the auto-rejoin procedure, the member can be stopped manually at any time by using a  STOP GROUP_REPLICATION  statement or shutting down the server. If you cannot tolerate the possibility of stale reads for any period of time, set the group_replication_autorejoin_tries  system variable to 0. You can monitor the auto-rejoin procedure using the Performance Schema. While an auto- rejoin procedure is taking place, the Performance Schema table  events_stages_current shows the event “Undergoing auto-rejoin procedure” , with the number of retries that have been attempted so far during this instance of the procedure (in the  WORK_COMPLETED  field). The events_stages_summary_global_by_event_name  table shows the number of times the server instance has initiated the auto-rejoin procedure (in the  COUNT_STAR  field). The events_stages_history_long  table shows the time each of these auto-rejoin procedures was completed (in the  TIMER_END  field). The  group_replication_exit_state_action  system variable, which is available from MySQL 8.0.12 and MySQL 5.7.24, specifies what Group Replication does when the member leaves the group unintentionally due to an error or problem, and either fails to auto-rejoin or does not try. Note that in the case of an expelled member, the member does not know that it was expelled until it reconnects to the group, so the specified action is only taken if the member manages to reconnect, or if the member raises a suspicion on itself and expels itself. In order of impact, the exit actions are as follows: 3784 18.7.6.4 Exit Action 1. If  READ_ONLY  is the exit action, the instance switches MySQL to super read only mode by setting the system variable  super_read_only  to  ON . When the member is in super read only mode, clients cannot make any updates, even if they have the  CONNECTION_ADMIN  privilege (or the deprecated SUPER  privilege). However, clients can still read data, and because updates are no longer being made, there is a probability of stale reads which increases over time. With this setting, you therefore need to pro-actively monitor the servers for failures. This exit action is the default from MySQL 8.0.15. After this exit action is taken, the member’s status is displayed as  ERROR  in the view of the group. 2. If  OFFLINE_MODE  is the exit action, the instance switches MySQL to offline mode by setting the system variable  offline_mode  to  ON . When the member is in offline mode, connected client users are disconnected on their next request and connections are no longer accepted, with the exception of client users that have the  CONNECTION_ADMIN  privilege (or the deprecated  SUPER  privilege). Group Replication also sets the system variable  super_read_only  to  ON , so clients cannot make any updates, even if they have connected with the  CONNECTION_ADMIN  or  SUPER  privilege. This exit action prevents both updates and stale reads (with the exception of reads by client users with