Responses to Failure Detection and Network Partitioning You can use the Group Replication configuration options described in this section to change these behaviors either permanently or temporarily, to suit your system’s requirements and your priorities. If you are experiencing unnecessary expulsions caused by slower networks or machines, networks with a high rate of unexpected transient outages, or planned network outages, consider increasing the expel timeout and auto-rejoin attempts. From MySQL 8.0.21, the default settings have been changed in this direction to reduce the frequency of the need for operator intervention to reinstate expelled members in these situations. Note that while a member is undergoing any of the default behaviors described above, although it does not accept writes, reads can still be made if the member is still communicating with clients, with an increasing likelihood of stale reads over time. If avoiding stale reads is a higher priority for you than avoiding operator intervention, consider reducing the expel timeout and auto-rejoin attempts or setting them to zero. Members that have not failed might lose contact with part, but not all, of the replication group due to a network partition. For example, in a group of 5 servers (S1,S2,S3,S4,S5), if there is a disconnection between (S1,S2) and (S3,S4,S5) there is a network partition. The first group (S1,S2) is now in a minority because it cannot contact more than half of the group. Any transactions that are processed by the members in the minority group are blocked, because the majority of the group is unreachable, therefore the group cannot achieve quorum. For a detailed description of this scenario, see Section 18.5.4, “Network Partitioning” . In this situation, the default behavior is for the members in both the minority and the majority to remain in the group, continue to accept transactions (although they are blocked on the members in the minority), and wait for operator intervention. This behavior is also configurable. Note that where group members are at an older MySQL Server release that does not support a relevant setting, or at a release with a different default, they act towards themselves and other group members according to the default behaviors stated above. For example, a member that does not support the