MySQL MGR原理及部署
阿新 • • 發佈：2020-07-14
轉載自：https://www.cnblogs.com/sallyluo/p/11760304.html
MySQL 5.7 MGR
1、背景
主從複製，一主多從，主庫提供讀寫功能，從庫提供只讀功能。當一個事務在master 提交成功時，會把binlog檔案同步到從庫伺服器上落地為relay log給slave端執行，這個過程主庫是不考慮從庫是否有接收到binlog檔案，有可能出現這種情況，當主庫commit一個事務後，資料庫發生宕機，剛好它的binlog還沒來得及傳送到slave端，這個時候選任何一個slave端都會丟失這個事務，造成資料不一致情況。 為了避免出現主從資料不一致的情況，MySQL引入了半同步複製，新增多了一個從庫反饋機制，即半同步複製。這個有兩種方式設定：
- 主庫執行完事務後，同步binlog給從庫，從庫ack反饋接收到binlog，主庫提交commit，反饋給客戶端，釋放會話；
- 主庫執行完事務後，主庫提交commit ，同步binlog給從庫，從庫ack反饋接收到binlog，反饋給客戶端，釋放會話；
但是，雖然滿足了一主多從，讀寫分析，資料一致，但是，依舊有兩個弊端：
- 寫操作只能在master上；
- 如果master宕機，需要人為選擇新主並重新給其他的slave端執行change master；
為了解決一系列問題，官方推出了MySQL Group Replication，從group replication釋出以後，就有3種方法來實現MySQL的高可用叢集：
- 非同步複製
- 半同步複製
- group replication
2、Group Replication原理
MySQL Group Replication有兩種模式，單主模式single-primary mode和多主模式multi-primary mode，在同一個group內，不允許兩種模式同時存在，並且若要切換到不同模式，必須修改配置後重新啟動叢集。
1、單主模式
在單主模式下，只有一個節點可以讀寫，其他節點提供只讀服務。單主模式下，該引數 _ 必須被設定為 FALSE ，當主節點宕掉，自動會根據伺服器的server_uuid變數和group_replication_member_weight變數值，選擇下一個slave誰作為主節點，group_replication_member_weight的值最高的成員被選為新的主節點，該引數預設為50，建議可以在節點上設定不同值；在group_replication_member_weight值相同的情況下，group根據資料字典中 server_uuid排序，排序在最前的被選擇為主節點。
- 單主模式中發現當前的主伺服器，該值VARIABLE_VALUE為例項節點的server_uuid：
select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
2、多主模式
在mysql多主模式下,在組複製中通過Group Replication Protocol協議及Paxos協議，形成的整體高可用解決方案 同時增加了certify的概念，負責檢查事務是否允許提交，是否與其它事務存在衝突,Group Replication是由多個節點共同組成一個數據庫叢集，每個節點都可以單獨執行事務，但是read-write（rw）的操作只有在組內驗證後才可以commit，Read-only (RO)事務是不需要驗證可以立即執行，當一個事務在一個節點上提交之前，會在組內自動進行原子性的廣播，告知其他節點變更了什麼內容/執行了什麼事務，然後為該事物建立一個全域性的排序，最終，這意味著所有的伺服器都以相同的順序接收相同的事務集。因此，所有伺服器都按照相同的順序應用相同的變更集，因此它們在組中保持一致。 在多主模式下，該組的所有成員都設定為讀寫模式，在多主模式下，不支援SERIALIZABLE事務隔離級別，且不能完全支援級聯外來鍵約束。
3、配置要求和限制
- inndb儲存引擎；
- 每個表需要定義顯式主鍵；
- 隔離級別：官網建議READ COMMITTED級別，不支援SERIALIZABLE隔離級別；
- 不建議使用級聯外來鍵；
- IPv4網路；
- auto_increment_increment和auto_increment_offset的配置；
- log-bin = ROW；
- log_slave_updates = ON；
- 開啟GTID；
- 安裝引擎：group_replication.so；
4、搭建Mysql Group Replication
- 基礎資訊如下:
| IP | port | server_id | server_uuid |
|---|---|---|---|
| 172.17.0.37（A） | 3306 | 1001 | b13df29e-90b6-11e8-8d1b-525400fc3993 |
| 172.17.0.48（B） | 3306 | 1002 | 1fa7b3ca-9475-11e8-a217-5254004e7cfe |
| 172.17.0.2 （C） | 3306 | 1003 | 81d824f1-90ba-11e8-a83d-52540043d75a |
- my.cnf配置檔案:
#172.17.0.37（A）:
[mysqld]
datadir=/usr/local/mysql/data
socket=/usr/local/mysql/data/mysql.sock
character_set_server=utf8
init_connect='SET NAMES utf8'
lower_case_table_names = 1
# Disabling symbolic-links is rmended to prevent assorted security risks
symbolic-links=0
log-error=/usr/local/mysql/logs/mysqld.log
pid-file=/usr/local/mysql/pids/mysqld.pid
# Group Replication
server_id = 1001
gtid_mode = ON
enforce_gtid_consistency = ON
master_info_repository = TABLE
relay_log_info_repository = TABLE
binlog_checksum = NONE
log_slave_updates = ON
log_bin = binlog
binlog_format= ROW
transaction_write_set_extraction ='XXHASH64'
loose-group_replication_group_name = 'b13df29e-90b6-11e8-8d1b-525400fc3996'
loose-group_replication_start_on_boot = off
loose-group_replication_local_address = '172.17.0.37:10061'
loose-group_replication_group_seeds ='172.17.0.37:10061,172.17.0.2:10063,172.17.0.48:10062'
loose-group_replication_bootstrap_group = off
group_replication_ip_whitelist = '172.17.0.37,172.17.0.2,172.17.0.48'
report_host='172.17.0.37'
log_timestamps='system'
plugin-dir=/usr/local/mysql/plugin
--------------------------------------------------------------------------------
172.17.0.48（B）:
[mysqld]
datadir=/usr/local/mysql/data
socket=/usr/local/mysql/data/mysql.sock
character_set_server=utf8
init_connect='SET NAMES utf8'
lower_case_table_names = 1
# Disabling symbolic-links is rmended to prevent assorted security risks
symbolic-links=0
log-error=/usr/local/mysql/logs/mysqld.log
pid-file=/usr/local/mysql/pids/mysqld.pid
# Group Replication
server_id = 1002
gtid_mode = ON
enforce_gtid_consistency = ON
master_info_repository = TABLE
relay_log_info_repository = TABLE
binlog_checksum = NONE
log_slave_updates = ON
log_bin = binlog
binlog_format= ROW
transaction_write_set_extraction ='XXHASH64'
loose-group_replication_group_name = 'b13df29e-90b6-11e8-8d1b-525400fc3996'
loose-group_replication_start_on_boot = off
loose-group_replication_local_address = '172.17.0.48:10062'
loose-group_replication_group_seeds ='172.17.0.37:10061,172.17.0.2:10063,172.17.0.48:10062'
loose-group_replication_bootstrap_group = off
group_replication_ip_whitelist = '172.17.0.37,172.17.0.2,172.17.0.48'
log_timestamps='system'
report_host='172.17.0.48'
plugin-dir=/usr/local/mysql/plugin
--------------------------------------------------------------------------------
172.17.0.2 （C）:
[mysqld]
datadir=/usr/local/mysql/data
socket=/usr/local/mysql/data/mysql.sock
character_set_server=utf8
init_connect='SET NAMES utf8'
lower_case_table_names = 1
# Disabling symbolic-links is rmended to prevent assorted security risks
symbolic-links=0
log-error=/usr/local/mysql/logs/mysqld.log
pid-file=/usr/local/mysql/pids/mysqld.pid
# Group Replication
server_id = 1003
gtid_mode = ON
enforce_gtid_consistency = ON
master_info_repository = TABLE
relay_log_info_repository = TABLE
binlog_checksum = NONE
log_slave_updates = ON
log_bin = binlog
binlog_format= ROW
transaction_write_set_extraction ='XXHASH64'
loose-group_replication_group_name = 'b13df29e-90b6-11e8-8d1b-525400fc3996'
loose-group_replication_start_on_boot = off
loose-group_replication_local_address = '172.17.0.2:10063'
loose-group_replication_group_seeds ='172.17.0.37:10061,172.17.0.2:10063,172.17.0.48:10062'
loose-group_replication_bootstrap_group = off
group_replication_ip_whitelist = '172.17.0.37,172.17.0.2,172.17.0.48'
log_timestamps='system'
report_host='172.17.0.2'
plugin-dir=/usr/local/mysql/plugin
- 建立複製賬號:
A、B、C：
grant replication slave on *.* to rpl_user@'%' identified by 'rpl_pass';
- 安裝引擎:
INSTALL PLUGIN group_replication SONAME 'group_replication.so';
show plugins;
1、單主模式（set global groupreplicationsingleprimarymode =ON）:
- 配置Group:
172.17.0.37：
mysql> set global group_replication_single_primary_mode=on;
Query OK, 0 rows affected (0.00 sec)
mysql> SET GLOBAL group_replication_bootstrap_group=ON;
Query OK, 0 rows affected (0.00 sec)
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.07 sec)
mysql> start group_replication;
Query OK, 0 rows affected, 1 warning (2.08 sec)
mysql> SET GLOBAL group_replication_bootstrap_group=OFF;
Query OK, 0 rows affected (0.00 sec)
172.17.0.48和172.17.0.2：
mysql> set global group_replication_single_primary_mode=on;
Query OK, 0 rows affected (0.00 sec)
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.05 sec)
mysql> start group_replication;
Query OK, 0 rows affected (5.81 sec)
172.17.0.37：
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> show variables like '%read_on%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
mysql> show variables like '%server_uuid%';
+---------------+--------------------------------------+
| Variable_name | Value |
+---------------+--------------------------------------+
| server_uuid | b13df29e-90b6-11e8-8d1b-525400fc3993 |
+---------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+--------------------------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+--------------------------------------+
| group_replication_primary_member | b13df29e-90b6-11e8-8d1b-525400fc3993 |
+----------------------------------+--------------------------------------+
1 row in set (0.01 sec)
mysql> show variables like '%group_replication_member_weight%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| group_replication_member_weight | 80 |
+---------------------------------+-------+
1 row in set (0.00 sec)
172.17.0.48：
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> show variables like '%read_on%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | ON |
| super_read_only | ON |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+--------------------------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+--------------------------------------+
| group_replication_primary_member | b13df29e-90b6-11e8-8d1b-525400fc3993 |
+----------------------------------+--------------------------------------+
1 row in set (0.01 sec)
mysql> show variables like '%server_uuid%';
+---------------+--------------------------------------+
| Variable_name | Value |
+---------------+--------------------------------------+
| server_uuid | 1fa7b3ca-9475-11e8-a217-5254004e7cfe |
+---------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> show variables like '%group_replication_member_weight%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| group_replication_member_weight | 50 |
+---------------------------------+-------+
1 row in set (0.00 sec)
172.17.0.2：
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> show variables like '%read_on%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | ON |
| super_read_only | ON |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+--------------------------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+--------------------------------------+
| group_replication_primary_member | b13df29e-90b6-11e8-8d1b-525400fc3993 |
+----------------------------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> show variables like '%server_uuid%';
+---------------+--------------------------------------+
| Variable_name | Value |
+---------------+--------------------------------------+
| server_uuid | 81d824f1-90ba-11e8-a83d-52540043d75a |
+---------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> show variables like '%group_replication_member_weight%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| group_replication_member_weight | 100 |
+---------------------------------+-------+
1 row in set (0.01 sec)
單主故障處理
（1）非主資料庫掛掉
172.17.0.48：
[root@VM_0_48_centos ~]# service mysqld stop
Shutting down MySQL............. SUCCESS!
172.17.0.37/172.17.0.2：
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
2 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+--------------------------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+--------------------------------------+
| group_replication_primary_member | b13df29e-90b6-11e8-8d1b-525400fc3993 |
+----------------------------------+--------------------------------------+
172.17.0.48：
mysql> use sissi_01;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+--------------------+
| Tables_in_sissi_01 |
+--------------------+
| tab |
+--------------------+
1 row in set (0.00 sec)
mysql> select * from tab;
+----+------+
| id | name |
+----+------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
+----+------+
25 rows in set (0.00 sec)
mysql> insert into tab select 97,'tencent';
Query OK, 1 row affected (0.03 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
+----+---------+
26 rows in set (0.00 sec)
172.17.0.2：
mysql> select * from tab;
ERROR 1046 (3D000): No database selected
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
+----+---------+
26 rows in set (0.00 sec)
172.17.0.48：
[root@VM_0_48_centos ~]# service mysqld start
Starting MySQL. SUCCESS!
mysql> select * from performance_schema.replication_group_members;
+---------------------------+-----------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+-----------+-------------+-------------+--------------+
| group_replication_applier | | | NULL | OFFLINE |
+---------------------------+-----------+-------------+-------------+--------------+
1 row in set (0.00 sec)
mysql> set global group_replication_single_primary_mode=on;
Query OK, 0 rows affected (0.00 sec)
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.11 sec)
mysql> start group_replication;
Query OK, 0 rows affected (3.27 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
+----+---------+
26 rows in set (0.00 sec)（2）主資料庫掛掉
172.17.0.37：
[root@VM_0_37_centos ~]# service mysqld stop
Shutting down MySQL............ SUCCESS!
172.17.0.2：
mysql> show variables like '%group_replication_member_weight%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| group_replication_member_weight | 100 |
+---------------------------------+-------+
1 row in set (0.01 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
2 rows in set (0.00 sec)
mysql> show variables like '%read_on%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.01 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+--------------------------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+--------------------------------------+
| group_replication_primary_member | 81d824f1-90ba-11e8-a83d-52540043d75a |
+----------------------------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> show variables like '%server_uuid%';
+---------------+--------------------------------------+
| Variable_name | Value |
+---------------+--------------------------------------+
| server_uuid | 81d824f1-90ba-11e8-a83d-52540043d75a |
+---------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> insert into sissi_01.tab select 98 ,'sng001';
Query OK, 1 row affected (0.02 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
+----+---------+
27 rows in set (0.00 sec)
172.17.0.48：
mysql> show variables like '%group_replication_member_weight%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| group_replication_member_weight | 50 |
+---------------------------------+-------+
1 row in set (0.01 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
2 rows in set (0.00 sec)
mysql> show variables like '%read_on%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | ON |
| super_read_only | ON |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+--------------------------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+--------------------------------------+
| group_replication_primary_member | 81d824f1-90ba-11e8-a83d-52540043d75a |
+----------------------------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> show variables like '%server_uuid%';
+---------------+--------------------------------------+
| Variable_name | Value |
+---------------+--------------------------------------+
| server_uuid | 1fa7b3ca-9475-11e8-a217-5254004e7cfe |
+---------------+--------------------------------------+
1 row in set (0.00 sec)
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
+----+---------+
27 rows in set (0.00 sec)
172.17.0.37：
[root@VM_0_37_centos ~]# service mysqld start
Starting MySQL. SUCCESS!
mysql> select * from performance_schema.replication_group_members;
+---------------------------+-----------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+-----------+-------------+-------------+--------------+
| group_replication_applier | | | NULL | OFFLINE |
+---------------------------+-----------+-------------+-------------+--------------+
1 row in set (0.00 sec)
mysql> set global group_replication_single_primary_mode=on;
Query OK, 0 rows affected (0.00 sec)
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.07 sec)
mysql> start group_replication;
Query OK, 0 rows affected (2.93 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
+----+---------+
27 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+--------------------------------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+--------------------------------------+
| group_replication_primary_member | 81d824f1-90ba-11e8-a83d-52540043d75a |
+----------------------------------+--------------------------------------+
1 row in set (0.00 sec)
#### 2、多主模式（set global group_replication_single_primary_mode =OFF）:
172.17.0.37/2/48：
mysql> set global group_replication_single_primary_mode =OFF;
Query OK, 0 rows affected (0.00 sec)
172.17.0.37：
mysql> set global group_replication_bootstrap_group=ON;
Query OK, 0 rows affected (0.00 sec)
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.06 sec)
mysql> start group_replication;
Query OK, 0 rows affected (2.09 sec)
mysql> set global group_replication_bootstrap_group=Off;
Query OK, 0 rows affected (0.00 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+----------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+----------------+
| group_replication_primary_member | |
+----------------------------------+----------------+
1 row in set (0.00 sec)
mysql> show variables like '%read_only%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
| 99 | sng002 |
+----+---------+
28 rows in set (0.00 sec)
172.17.0.2：
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.04 sec)
mysql> start group_replication;
Query OK, 0 rows affected (3.26 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+----------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+----------------+
| group_replication_primary_member | |
+----------------------------------+----------------+
1 row in set (0.00 sec)
mysql> show variables like '%read_only%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
mysql> insert into sissi_01.tab select 98 ,'sng002';
ERROR 1062 (23000): Duplicate entry '98' for key 'PRIMARY'
mysql> insert into sissi_01.tab select 99 ,'sng002';
Query OK, 1 row affected (0.01 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
| 99 | sng002 |
+----+---------+
28 rows in set (0.00 sec)
172.17.0.48:
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.05 sec)
mysql> start group_replication;
Query OK, 0 rows affected (5.80 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> select * from performance_schema.global_status WHERE VARIABLE_NAME like '%group_replication%';
+----------------------------------+----------------+
| VARIABLE_NAME | VARIABLE_VALUE |
+----------------------------------+----------------+
| group_replication_primary_member | |
+----------------------------------+----------------+
1 row in set (0.00 sec)
mysql> show variables like '%read_only%';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| innodb_read_only | OFF |
| read_only | OFF |
| super_read_only | OFF |
| transaction_read_only | OFF |
| tx_read_only | OFF |
+-----------------------+-------+
5 rows in set (0.00 sec)
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
| 99 | sng002 |
+----+---------+
28 rows in set (0.00 sec)多主故障處理
172.17.0.48：
[root@VM_0_48_centos ~]# service mysqld stop
Shutting down MySQL............ SUCCESS!
mysql> insert into sissi_01.tab select 99 ,'sng002';
Query OK, 1 row affected (0.01 sec)
Records: 1 Duplicates: 0 Warnings: 0
172.17.0.2：
mysql> select * from sissi_01.tab;
+----+---------+
| id | name |
+----+---------+
| 1 | NULL |
| 2 | NULL |
| 7 | NULL |
| 8 | NULL |
| 9 | NULL |
| 10 | NULL |
| 13 | aa |
| 20 | aa |
| 27 | aa |
| 41 | bb |
| 42 | cc |
| 47 | ddd |
| 54 | ee |
| 61 | ff |
| 68 | gg |
| 75 | hh |
| 76 | hh |
| 77 | hh |
| 78 | ii |
| 79 | ggw |
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
| 99 | sng002 |
+----+---------+
28 rows in set (0.00 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
2 rows in set (0.00 sec)
172.17.0.37：
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
2 rows in set (0.00 sec)
mysql> insert into sissi_01.tab select 100 ,'sng003';
Query OK, 1 row affected (0.03 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> select * from sissi_01.tab;
+-----+---------+
| id | name |
+-----+---------+
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
| 99 | sng002 |
| 100 | sng003 |
+-----+---------+
29 rows in set (0.00 sec)
172.17.0.48：
[root@VM_0_48_centos ~]# service mysqld start
Starting MySQL. SUCCESS!
mysql> set global group_replication_single_primary_mode =OFF;
Query OK, 0 rows affected (0.00 sec)
mysql> CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
Query OK, 0 rows affected, 2 warnings (0.06 sec)
mysql> start group_replication;
Query OK, 0 rows affected (2.72 sec)
mysql> select * from performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| CHANNEL_NAME | MEMBER_ID | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
| group_replication_applier | 1fa7b3ca-9475-11e8-a217-5254004e7cfe | 172.17.0.48 | 3306 | ONLINE |
| group_replication_applier | 81d824f1-90ba-11e8-a83d-52540043d75a | 172.17.0.2 | 3306 | ONLINE |
| group_replication_applier | b13df29e-90b6-11e8-8d1b-525400fc3993 | 172.17.0.37 | 3306 | ONLINE |
+---------------------------+--------------------------------------+-------------+-------------+--------------+
3 rows in set (0.00 sec)
mysql> select * from sissi_01.tab;
+-----+---------+
| id | name |
+-----+---------+
| 80 | cccc |
| 81 | coco |
| 84 | kk |
| 90 | kk2 |
| 96 | kk4 |
| 97 | tencent |
| 98 | sng001 |
| 99 | sng002 |
| 100 | sng003 |
+-----+---------+
29 rows in set (0.00 sec)補充：模擬一個節點和兩個節點掛恢復是一樣的：
set global group_replication_single_primary_mode =OFF;
CHANGE MASTER TO MASTER_USER='rpl_user', MASTER_PASSWORD='rpl_pass' FOR CHANNEL 'group_replication_recovery';
start group_replication;