MySQL 8.4 Release Notes
本节解释了如何升级 Group Replication 设置。升级组成员的基本过程与升级独立实例相同，实际的升级过程和可用类型请参见 第 3 章，升级 MySQL。选择进行原地升级还是逻辑升级取决于组中存储的数据量。通常情况下，原地升级更快，因此推荐使用。您还应参考 第 19.5.3 节，“升级或降级复制拓扑”。This section explains how to upgrade a Group Replication setup. The basic process of upgrading members of a group is the same as upgrading stand-alone instances, see Chapter 3, Upgrading MySQL for the actual process of doing upgrade and types available. Choosing between an in-place or logical upgrade depends on the amount of data stored in the group. Usually an in-place upgrade is faster, and therefore is recommended. You should also consult Section 19.5.3, “Upgrading or Downgrading a Replication Topology”.
Note
在 MySQL 8.4 之前，如果服务器运行的 MySQL 版本低于该组中最低版本的成员，服务器将无法加入该组。例如，对于一个包含 S1 (8.0.30)、S2 (8.0.31) 和 S3 (8.0.32) 的组，要加入的成员需要是 8.0.30 或更高版本。MySQL 8.4 允许 8.4 系列内的所有版本加入。例如，8.4.0 服务器可以加入包含 S1 (8.4.1) 和 S2 (8.4.2) 的组。Before MySQL 8.4, a server would not join a group if it was running a lower MySQL Server version than the lowest group member's version. For example, for a group with S1 (8.0.30), S2 (8.0.31), and S3 (8.0.32), the joining member needs to be 8.0.30 or higher. MySQL 8.4 allows all versions within the 8.4 series to join. For example, an 8.4.0 server could join a group consisting of S1 (8.4.1) and S2 (8.4.2).
在升级在线组的过程中，为了最大化可用性，您可能需要让具有不同 MySQL 服务器版本的成员同时运行。组复制包括兼容性策略，使您能够在升级过程中安全地在同一组中组合运行不同 MySQL 版本的成员。根据您的组，这些策略的影响可能会影响您升级组成员的顺序。有关详细信息，请参见 第 20.8.1 节，“在组中组合不同成员版本”。While you are in the process of upgrading an online group, in order to maximize availability, you might need to have members with different MySQL Server versions running at the same time. Group Replication includes compatibility policies that enable you to safely combine members running different versions of MySQL in the same group during the upgrade procedure. Depending on your group, the effects of these policies might affect the order in which you should upgrade group members. For details, see Section 20.8.1, “Combining Different Member Versions in a Group”.
如果您的组可以完全脱机，请参见 第 20.8.2 节，“组复制脱机升级”。如果您的组需要保持在线，如生产部署中常见的情况，请参见 第 20.8.3 节，“组复制在线升级”，了解在最小停机时间内升级组的不同方法。If your group can be taken fully offline see Section 20.8.2, “Group Replication Offline Upgrade”. If your group needs to remain online, as is common with production deployments, see Section 20.8.3, “Group Replication Online Upgrade” for the different approaches available for upgrading a group with minimal downtime.