MGR 多主和單主的切換

MGR 驗證測試

架構：

10.0.1.111
10.0.1.147
10.0.1.192

MySQL [test]> select * from performance_schema.replication_group_members;

+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME              | MEMBER_ID                            | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 9208c7e9-2300-11eb-84ce-fa163e3bdc68 | master      |        3307 | ONLINE       |
| group_replication_applier | 922aea0f-2300-11eb-ade9-fa163e185828 | slave1      |        3307 | ONLINE       |
| group_replication_applier | 9234c4e6-2300-11eb-a184-fa163e313879 | slave2      |        3307 | ONLINE       |
+---------------------------+--------------------------------------+-------------+-------------+--------------+

2、多主切換到單主

一、中止組複製

mysql> show variables like '%group_replication_enforce_update_everywhere_checks%';
+----------------------------------------------------+-------+
| Variable_name                                      | Value |
+----------------------------------------------------+-------+
| group_replication_enforce_update_everywhere_checks | ON    |
+----------------------------------------------------+-------+
1 row in set (0.01 sec)

每一個節點執行：

mysql> set global group_replication_enforce_update_everywhere_checks=off;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like '%group_replication_single_primary_mode%';
+---------------------------------------+-------+
| Variable_name                         | Value |
+---------------------------------------+-------+
| group_replication_single_primary_mode | OFF   |
+---------------------------------------+-------+
1 row in set (0.01 sec)

mysql> set global group_replication_single_primary_mode=on;
Query OK, 0 rows affected (0.00 sec)

二、擇一個節點,打開 group_replication_bootstrap_group 爲 on，並開啓組複製，成功後再關閉

set global group_replication_bootstrap_group=on;
start group_replication;
set global group_replication_bootstrap_group=off;

另外兩個節點逐一開啓組複製，加入集羣環境，並經過視圖查看集羣狀況

start group_replication;
select * from performance_schema.replication_group_members;

#查看 Primary 成員
select *from  performance_schema.replication_group_members where member_id =(select variable_value from performance_schema.global_status WHERE VARIABLE_NAME= 'group_replication_primary_member');