MGR參數之group_replication_member_weight

一、環境

MGR 8.0.17 三節點，roidb1、roidb2、roidb3

二、測試

1、默認group_replication_member_weight=50
2、設置roidb2的權重爲100
set global group_replication_member_weight=100;
3、關閉主庫，shutdown;
4、查看主庫，roidb2自動failover爲主
mysql> select member_host,member_role from replication_group_members;
+-------------+-------------+
| member_host | member_role |
+-------------+-------------+
| roidb2      | PRIMARY     |
| roidb1      | SECONDARY   |
+-------------+-------------+
2 rows in set (0.00 sec)

三、知識點

通過設置此從參數來控制單主模式切換的順序，前提MGR多節點的版本爲統一版本。
group_replication_member_weight

Property       Value
Command-Line Format --group-replication-member-weight=#
Introduced      8.0.2
System Variable group_replication_member_weight
Scope              Global
Dynamic         Yes
SET_VAR Hint Applies    No
Type                   Integer
Default Value     50
Minimum Value   0
Maximum Value   100