今天分享的是mysql数据库的主主复制和半同步复制的一系列步骤，以及在各处出现错误的解决方法和其在操作过程中需要注意的地方
范例：主主复制
主主复制：两个节点，都可以更新数据，并且互为主从
容易产生的问题：数据不一致；因此慎用
考虑要点：自动增长id
配置一个节点使用奇数id
auto_increment_offset=1 #开始点
auto_increment_increment=2 #增长幅度
另一个节点使用偶数id
auto_increment_offset=2
auto_increment_increment=2
范例：
1#因为之前已经成功执行级联复制，所以只需进行后面连接
#先停掉从节点服务复制关系
mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.03 sec)
2.#清理掉复制关系
mysql> reset slave all;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> show slave status\G
Empty set, 1 warning (0.00 sec)
3.#在次节点上查看二进制位置
mysql> show master logs;
+-------------------+-----------+-----------+
| Log_name | File_size | Encrypted |
+-------------------+-----------+-----------+
| rocky8-bin.000001 | 180 | No |
| rocky8-bin.000002 | 180 | No |
| rocky8-bin.000003 | 205 | No |
| rocky8-bin.000004 | 205 | No |
| rocky8-bin.000005 | 205 | No |
| rocky8-bin.000006 | 205 | No |
| rocky8-bin.000007 | 180 | No |
| rocky8-bin.000008 | 4628487 | No |
+-------------------+-----------+-----------+
8 rows in set (0.00 sec)
4.#因为刚才的复制关系没了，复制输入，重新指向次节点
mysql> CHANGE MASTER TO MASTER_HOST='10.0.0.161',
-> MASTER_USER='repluser',
-> MASTER_PASSWORD='123456',
-> MASTER_LOG_FILE='rocky8-bin.000008 ',
-> MASTER_LOG_POS=4628487;
Query OK, 0 rows affected, 8 warnings (0.02 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 10.0.0.161
Master_User: repluser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: rocky8-bin.000008
Read_Master_Log_Pos: 4628487
Relay_Log_File: relay-log.000001
Relay_Log_Pos: 4
Relay_Master_Log_File: rocky8-bin.000008
Slave_IO_Running: No
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 4628487
Relay_Log_Space: 157
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 0
Master_UUID:
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
Master_public_key_path:
Get_master_public_key: 0
Network_Namespace:
1 row in set, 1 warning (0.00 sec)
#起服务
mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.02 sec)
#在第一个master节点上实现
[root@master1 ~]#vim /etc/my.cnf.d/mariadb-server.cnf
[mysqld]
server-id=8
log-bin
auto_increment_offset=1 #开始点
auto_increment_increment=2 #增长幅度
[root@master1 ~]#systemctl start mariadb
[root@master1 ~]#mysql
MariaDB [(none)]>show master logs;
+--------------------+-----------+
| Log_name | File_size |
+--------------------+-----------+
| mariadb-bin.000001 | 28303 |
| mariadb-bin.000002 | 386 |
+--------------------+-----------+
2 rows in set (0.000 sec)
MariaDB [(none)]> grant replication slave on *.* to repluser@'192.168.100.%'
identified by 'wang';
#在第二个master节点上实现
[rootmaster2 ~]#vim /etc/my.cnf.d/mariadb-server.cnf
[mysqld]
server-id=18
log-bin
auto_increment_offset=2 #开始点
auto_increment_increment=2 #增长幅度
[root@master2 ~]#systemctl start mariadb
[root@master2 ~]#mysql
MariaDB [(none)]> CHANGE MASTER TO
-> MASTER_HOST='192.168.100.8',
-> MASTER_USER='repluser',
-> MASTER_PASSWORD='wang',
-> MASTER_PORT=3306,
-> MASTER_LOG_FILE='mariadb-bin.000002',
-> MASTER_LOG_POS=386;
Query OK, 0 rows affected (0.019 sec)
MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.003 sec)
MariaDB [(none)]> show master logs; #查看二进制位置
+--------------------+-----------+
| Log_name | File_size |
+--------------------+-----------+
| mariadb-bin.000001 | 28303 |
| mariadb-bin.000002 | 344 |
+--------------------+-----------+
2 rows in set (0.001 sec)
#在第一个master节点上实现
MariaDB [(none)]> CHANGE MASTER TO
-> MASTER_HOST='192.168.100.18',
-> MASTER_USER='repluser',
-> MASTER_PASSWORD='wang',
-> MASTER_PORT=3306,
-> MASTER_LOG_FILE='mariadb-bin.000002',
-> MASTER_LOG_POS=344;
Query OK, 0 rows affected (0.007 sec)
MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.002 sec)
MariaDB [db1]> create table t1(id int auto_increment primary key,name char(10));
#两个节点分别插入数据
#在第一个节点上执行
MariaDB [db1]> create database db1;
MariaDB [db1]> insert t1 (name) values('user1');
#在第二个节点上执行
MariaDB [db1]> insert t1 (name) values('user2');
#两个节点同时插入数据
MariaDB [db1]> insert t1 (name) values('userX');
MariaDB [db1]> select * from t1;
+----+-------+
| id | name |
+----+-------+
| 1 | user1 |
| 2 | user2 |
| 3 | userX
| 4 | userX |
+----+-------+
4 rows in set (0.001 sec)
#两个节点同时创建数据库，发生复制冲突
MariaDB [db1]> create database db2;
MariaDB [db1]> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.100.18
Master_User: repluser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mariadb-bin.000002
Read_Master_Log_Pos: 1029
Relay_Log_File: mariadb-relay-bin.000002
Relay_Log_Pos: 1110
Relay_Master_Log_File: mariadb-bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1007
Last_Error: Error 'Can't create database 'db2'; database
exists' on query. Default database: 'db2'. Query: 'create database db2'
Skip_Counter: 0
Exec_Master_Log_Pos: 897
Relay_Log_Space: 1553
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 1007
Last_SQL_Error: Error 'Can't create database 'db2'; database
exists' on query. Default database: 'db2'. Query: 'create database db2'
Replicate_Ignore_Server_Ids:
Master_Server_Id: 18
Master_SSL_Crl:
Master_SSL_Crlpath:
Using_Gtid: No
Gtid_IO_Pos:
Replicate_Do_Domain_Ids:
Replicate_Ignore_Domain_Ids:
Parallel_Mode: conservative
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Slave_DDL_Groups: 2
Slave_Non_Transactional_Groups: 0
Slave_Transactional_Groups: 2
1 row in set (0.003 sec)
范例：半同步复制
范例: CentOS8 在MySQL8.0 实现半同步复制
1.#查看插件文件
[root@centos8 ~]#rpm -ql mysql-server |grep semisync
/usr/lib64/mysql/plugin/semisync_master.so
/usr/lib64/mysql/plugin/semisync_slave.so
2.#master服务器配置
[root@master ~]#vim /etc/my.cnf.d/mysql-server.cnf
[mysqld]
server-id=8
log-bin
plugin-load-add = "semisync_master.so" #安装加载插件
rpl_semi_sync_master_enabled=ON #修改此行,需要先安装semisync_master.so插件后,再
重启,否则无法启动
rpl_semi_sync_master_timeout=3000 #设置3s内无法同步，也将返回成功信息给客户端
3.#slave服务器配置
[root@slave1 ~]#vim /etc/my.cnf.d/mysql-server.cnf
[mysqld]
server-id=18
plugin-load-add = "semisync_slave.so" #安装加载插件
rpl_semi_sync_slave_enabled=ON #修改此行,需要先安装semisync_slave.so插件后,再重启,否则
无法启动
[root@slave2 ~]#vim /etc/my.cnf.d/mysql-server.cnf
[mysqld]
server-id=28
rpl_semi_sync_slave_enabled=ON #修改此行,需要先安装semisync_slave.so插件后,再重启,否则
无法启动
4.#主服务器配置:
mysql>INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so'; #永久安装插
件
mysql>UNINSTALL PLUGIN rpl_semi_sync_master ;
mysql>SHOW PLUGINS; #查看插件
mysql>SET GLOBAL rpl_semi_sync_master_enabled=1; #临时修改变量
mysql>SET GLOBAL rpl_semi_sync_master_timeout = 3000; #超时长1s,默认值为10s
mysql>SHOW GLOBAL VARIABLES LIKE '%semi%';
+-------------------------------------------+------------+
| Variable_name | Value |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled | ON |
| rpl_semi_sync_master_timeout | 10000 |
| rpl_semi_sync_master_trace_level | 32 |
| rpl_semi_sync_master_wait_for_slave_count | 1 |
| rpl_semi_sync_master_wait_no_slave | ON |
| rpl_semi_sync_master_wait_point | AFTER_SYNC |
+-------------------------------------------+------------+
6 rows in set (0.00 sec)
mysql> SHOW GLOBAL STATUS LIKE '%semi%';
+--------------------------------------------+-------+
| Variable_name | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients | 2 |
| Rpl_semi_sync_master_net_avg_wait_time | 0 |
| Rpl_semi_sync_master_net_wait_time | 0 |
| Rpl_semi_sync_master_net_waits | 0 |
| Rpl_semi_sync_master_no_times | 1 |
| Rpl_semi_sync_master_no_tx | 2 |
| Rpl_semi_sync_master_status | ON |
| Rpl_semi_sync_master_timefunc_failures | 0 |
| Rpl_semi_sync_master_tx_avg_wait_time | 0 |
| Rpl_semi_sync_master_tx_wait_time | 0 |
| Rpl_semi_sync_master_tx_waits | 0 |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0 |
| Rpl_semi_sync_master_wait_sessions | 0 |
| Rpl_semi_sync_master_yes_tx | 0 |
+--------------------------------------------+-------+
14 rows in set (0.00 sec)
5.#从服务器配置:
mysql>INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so';
mysql>SET GLOBAL rpl_semi_sync_slave_enabled=1; #临时修改变量
mysql>SHOW GLOBAL VARIABLES LIKE '%semi%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| rpl_semi_sync_slave_enabled | ON |
| rpl_semi_sync_slave_trace_level | 32 |
+---------------------------------+-------+
2 rows in set (0.00 sec)
6.#注意:如果已经实现主从复制,需要stop slave;start slave;
mysql> stop slave;
mysql> start slave;
mysql> SHOW GLOBAL STATUS LIKE '%semi%';
+----------------------------+-------+
| Variable_name | Value |
+----------------------------+-------+
| Rpl_semi_sync_slave_status | ON |
+----------------------------+-------+
1 row in set (0.00 sec)
今天分享的就到这里，谢谢大家的观看！