6. MGR状态监控 | 深入浅出MGR
MGR和传统主从复制类似，在运行过程中主要关注各节点的运行状态，以及Secondary节点的事务是否有延迟。本文介绍如何监控MGR节点状态、事务状态等。
1. 节点状态监控
通过查询 performance_schema.replication_group_members 表即可知道MGR各节点的状态：
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+--------------+-------------+--------------+-------------+----------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION |
+---------------------------+--------------------------------------+--------------+-------------+--------------+-------------+----------------+
| group_replication_applier | af39db70-6850-11ec-94c9-00155d064000 | 192.168.6.27 | 4306 | ONLINE | PRIMARY | 8.0.25 |
| group_replication_applier | b05c0838-6850-11ec-a06b-00155d064000 | 192.168.6.27 | 4307 | ONLINE | SECONDARY | 8.0.25 |
| group_replication_applier | b0f86046-6850-11ec-92fe-00155d064000 | 192.168.6.27 | 4308 | ONLINE | SECONDARY | 8.0.25 |
+---------------------------+--------------------------------------+--------------+-------------+--------------+-------------+----------------+
