Group Replication System Variables with an IPv6 address when this member has an IPv4  group_replication_local_address , or the reverse, you must also set up and permit an alternative address for this member for the required protocol (or a host name that resolves to an address for that protocol). For more information, see Section 18.6.1, “Group Replication IP Address Permissions” . • group_replication_member_expel_timeout Command-Line Format --group-replication-member-expel- timeout=# Introduced 8.0.13 System Variable group_replication_member_expel_timeout Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value ( ≥  8.0.21) 5 Default Value ( ≤  8.0.20) 0 Minimum Value 0 Maximum Value ( ≥  8.0.14) 3600 Maximum Value ( ≤  8.0.13) 31536000 Unit seconds The value of this system variable can be changed while Group Replication is running, and the change takes effect immediately. The current value of the system variable is read whenever Group Replication checks the timeout. It is not mandatory for all members of a group to have the same setting, but it is recommended in order to avoid unexpected expulsions. group_replication_member_expel_timeout  specifies the period of time in seconds that a Group Replication group member waits after creating a suspicion, before expelling from the group the member suspected of having failed. The initial 5-second detection period before a suspicion is created does not count as part of this time. Up to and including MySQL 8.0.20, the value of group_replication_member_expel_timeout  defaults to 0, meaning that there is no waiting period and a suspected member is liable for expulsion immediately after the 5-second detection period ends. From MySQL 8.0.21, the value defaults to 5, meaning that a suspected member is liable for expulsion 5 seconds after the 5-second detection period. Changing the value of  group_replication_member_expel_timeout  on a group member takes effect immediately for existing as well as future suspicions on that group member. You can therefore use this as a method to force a suspicion to time out and expel a suspected member, allowing changes to the group configuration. For more information, see Section 18.7.6.1, “Expel Timeout” . Increasing the value of  group_replication_member_expel_timeout  can help to avoid unnecessary expulsions on slower or less stable networks, or in the case of expected transient network outages or machine slowdowns. If a suspect member becomes active again before the suspicion times out, it applies all the messages that were buffered by the remaining group members and enters ONLINE  state, without operator intervention. You can specify a timeout value up to a maximum of 3600 seconds (1 hour). It is important to ensure that XCom’s message cache is sufficiently large to contain the expected volume of messages in your specified time period, plus the initial 5-second detection period, otherwise members are unable to reconnect. You can adjust the cache size limit 3818