数据库MySQL（六）MySQL集群技术，一主一从，双主双从

目录

一、集群技术

1、集群目的

2、类型

3、MySQL复制技术原理示意图

二、集群案例

例1：一主一从（1）（M-S）

例2：一主一从（2）（M-S）

例3：双主双从（MM-SS）四台服务器

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一、集群技术

1、集群目的

负载均衡        解决高并发

高可用HA        服务可用性

远程灾备        数据有效性

2、类型

M        主

M-S        主-从

M-S-S...        主-多从

M-M        双主

M-M-S-S        双主双从    

3、MySQL复制技术原理示意图

 概念：

在主库上把数据更改（DDL DML DCL）记录到二进制日志（Binary Log）中；

备库I/O线程将主库上的日志复制到自己的中继日志（Relay Log）中；

备库SQL线程读取中继日志中的时间，将其放到备库数据库之上。

二、集群案例

• 例1：一主一从（1）（M-S）

主（master1）

//准备好一台新mysql服务器，准备好域名解析，两台都要做
[root@master1 ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.172.174 master1
192.168.172.166 slave1
//准备数据1（验证主从同步使用）
mysql> create table master1db.tab1(name char(50));
Query OK, 0 rows affected (0.02 sec)

mysql> insert into master1db.tab1 values(111);
Query OK, 1 row affected (0.03 sec)

mysql> insert into master1db.tab1 values(222);
Query OK, 1 row affected (0.01 sec)

mysql> select * from master1db.tab1;
+------+
| name |
+------+
| 111  |
| 222  |
+------+
2 rows in set (0.00 sec)

//开启二进制日志
[root@master1 ~]# vim /etc/my.cnf
[mysqld]
log_bin
server_id=1
[root@master1 ~]# systemctl restart mysqld
[root@master1 ~]# ls /var/lib/mysql
master1-bin.000001    //可以看到里面有这个文件

//创建复制用户
[root@master1 ~]# mysql -uroot -p'Qian@123'
mysql> grant replication slave,replication client on *.* to 'rep'@'192.168.172.%' identified by 'Qian@123';

//备份master数据库的数据
[root@master1 ~]# mysqldump -p'Qian@123' --all-databases --single-transaction --master-data=2 --flush-logs > `date +%F`-mysql-all.sql
[root@master1 ~]# ls
2022-10-14-mysql-all.sql  

//把备份传送到slave1
[root@master1 ~]# scp -r 2022-10-14-mysql-all.sql slave1:/tmp
The authenticity of host 'slave1 (192.168.172.166)' can't be established.
ECDSA key fingerprint is SHA256:HumQuxOX0NOaT9s/Lx2oTdcp3WZ+HnK0xD0tJQJTm54.
ECDSA key fingerprint is MD5:ef:0b:e0:47:5d:dc:ce:0e:d7:e4:e3:55:94:0a:63:ac.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'slave1,192.168.172.166' (ECDSA) to the list of known hosts.
root@slave1's password: 
2022-10-14-mysql-all.sql                           100%  861KB  50.2MB/s   00:00 

//到slave1看一下，备份成功
[root@slave1 ~]# ls /tmp/
2022-10-14-mysql-all.sql

//准备数据2（验证主从同步使用）
mysql> insert into master1db.tab1 values(333);
Query OK, 1 row affected (0.01 sec)

mysql> insert into master1db.tab1 values(444);
Query OK, 1 row affected (0.01 sec)

mysql> select * from master1db.tab1;
+------+
| name |
+------+
| 111  |
| 222  |
| 333  |
| 444  |
+------+
4 rows in set (0.00 sec)

 

从（slave1）

//测试rep用户是否可用，预防账户有问题，记得关闭防火墙，不关防火墙是登不进去的
[root@slave1 ~]# mysql -h master1 -urep -p'Qian@123'
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
+--------------------+
1 row in set (0.01 sec)

//启动服务器序号
[root@slave1 ~]# vim /etc/my.cnf
[mysqld]
server_id=2
[root@slave1 ~]# systemctl restart mysqld

//测试服务器是否修改正确，能否正常登录
[root@slave1 ~]# mysql -uroot -p'Linn@123'
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

//手动同步数据，暂停二进制日志
mysql> set sql_log_bin=0;
Query OK, 0 rows affected (0.00 sec)

//还原二进制文件
mysql> source /tmp/2022-10-14-mysql-all.sql    

mysql> select * from master1db.tab1;
+------+
| name |
+------+
| 111  |
| 222  |
+------+
2 rows in set (0.00 sec)

//注意，二进制日志的位置，应该参照主服务器备份时生成的新位置，查看一下备份文件2022-10-14-mysql-all.sql的第22行
mysql> change master to master_host='master1',master_user='rep',master_password='Qian@123',master_log_file='master1-bin.000002',master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

//启动从设备
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

//查看数据
mysql> select * from master1db.tab1;    //可以看到数据已经同步过来了
+------+
| name |
+------+
| 111  |
| 222  |
| 333  |
| 444  |
+------+

//返回主服务器master1更新数据，在从服务器slave1观察是否同步
//master1
mysql> insert into master1db.tab1 values(555);
Query OK, 1 row affected (0.01 sec)

mysql> insert into master1db.tab1 values(666);
Query OK, 1 row affected (0.01 sec)


//slave1
mysql> select * from master1db.tab1;    //同步成功
+------+
| name |
+------+
| 111  |
| 222  |
| 333  |
| 444  |
| 555  |
| 666  |
+------+
6 rows in set (0.00 sec)

//查看启动状态，如果遇到什么问题，可以看一下状态信息
mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: master1
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: master1-bin.000002
          Read_Master_Log_Pos: 1186
               Relay_Log_File: slave1-relay-bin.000002
                Relay_Log_Pos: 1354
        Relay_Master_Log_File: master1-bin.000002
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              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: 1186
              Relay_Log_Space: 1562
              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: 0
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: 1
                  Master_UUID: 20555f91-4ad8-11ed-a8ff-000c299c92f3
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           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: 
1 row in set (0.00 sec)

• 例2：一主一从（2）（M-S）

跟例1功能相同，不同之处，使用了“gtid_mode=ON          enforce_gtid_consistency=1” 该属性自动记录position位置，不需要手动指定了

主（master1）

//重置slave1数据库
[root@slave1 ~]# systemctl stop mysqld
[root@slave1 ~]# rm -rf /var/lib/mysql/*
[root@slave1 ~]# systemctl start mysqld
[root@slave1 ~]# grep password /var/log/mysqld.log 
2022-10-15T04:16:49.578713Z 1 [Note] A temporary password is generated for root@localhost: hZv+)vtVl3Cq
[root@slave1 ~]# mysqladmin -p'hZv+)vtVl3Cq' password 'Linn@123'
[root@slave1 ~]# mysql -p'Linn@123'

//master1配置
//启动二进制日志，服务器ID,GTID
[root@master1 ~]# vim /etc/my.cnf
[mysqld]
log_bin
server_id=1
gtid_mode=ON
enforce_gtid_consistency=1
[root@master1 ~]# systemctl restart mysqld
//授权复制用户rep，上面已经做过了，这里就不做了
//备份数据
[root@master1 ~]# mysqldump -p'Qian@123' --all-databases --single-transaction --master-data=2 --flush-logs > `date +%F`-mysql-all.sql
[root@master1 ~]# scp 2022-10-15-mysql-all.sql slave1:/tmp
root@slave1's password: 
2022-10-15-mysql-all.sql                           100%  861KB  28.1MB/s   00:00 
//模拟数据变化
[root@master1 ~]# mysql -uroot -p'Qian@123'
mysql> insert into master1db.tab1 values(7777);
Query OK, 1 row affected (0.01 sec)

mysql> insert into master1db.tab1 values(8888);
Query OK, 1 row affected (0.01 sec)

mysql> select * from master1db.tab1;
+------+
| name |
+------+
| 111  |
| 222  |
| 333  |
| 444  |
| 555  |
| 666  |
| 7777 |
| 8888 |
+------+
8 rows in set (0.00 sec)

从（slave1）

//测试rep用户是否可用
[root@slave1 ~]# mysql -h master1 -urep -p'Qian@123'
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
+--------------------+
1 row in set (0.00 sec)

//启动二进制日志，服务器ID,GTID
[mysqld]
log_bin
server_id=2
gtid_mode=ON
enforce_gtid_consistency=1
[root@slave1 ~]# systemctl restart mysqld
//恢复手动同步数据
[root@slave1 ~]# mysql -p'Linn@123'
mysql> set sql_log_bin=0;    //临时关闭二进制日志
Query OK, 0 rows affected (0.00 sec)

mysql> source /tmp/2022-10-15-mysql-all.sql
mysql> select * from master1db.tab1;
+------+
| name |
+------+
| 111  |
| 222  |
| 333  |
| 444  |
| 555  |
| 666  |
+------+
6 rows in set (0.00 sec)

//设置主服务器
mysql> change master to 
    -> master_host='master1',
    -> master_user='rep',
    -> master_password='Qian@123',
    -> master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

mysql> select * from master1db.tab1;
+------+
| name |
+------+
| 111  |
| 222  |
| 333  |
| 444  |
| 555  |
| 666  |
| 7777 |
| 8888 |
+------+
8 rows in set (0.00 sec)

//返回主服务器（master1）更新数据，在从服务器（slave1）观察是否同步
//master1
mysql> insert into master1db.tab1 values(999);
Query OK, 1 row affected (0.01 sec)
mysql> insert into master1db.tab1 values(1010);
Query OK, 1 row affected (0.01 sec)

//slave1
mysql> select * from master1db.tab1;
+------+
| name |
+------+
| 111  |
| 222  |
| 333  |
| 444  |
| 555  |
| 666  |
| 7777 |
| 8888 |
| 999  |
| 1010 |
+------+
10 rows in set (0.00 sec)

• 例3：双主双从（MM-SS）四台服务器

• 主操作

master2        到master2上面做一下上面slave1的操作，然后接着做下面的操作

[root@master2 ~]# mysql -p'Qian@12345'
//在master2上进行授权
mysql> grant replication slave,replication client on *.* to 'rep'@'192.168.172.%' identified by 'Qian@123';
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

master1

[root@master1 ~]# mysql -p'Qian@123'
mysql> change master to
    -> master_host='master2',
    -> master_user='rep',
    -> master_password='Qian@123',
    -> master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave;
Query OK, 0 rows affected (0.03 sec)

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Connecting to master
                  Master_Host: master2    //这里可以看到master1的主人为master2
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: 
          Read_Master_Log_Pos: 4
               Relay_Log_File: master1-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: 
             Slave_IO_Running: Connecting
            Slave_SQL_Running: Yes
              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: 0
              Relay_Log_Space: 154
              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: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 2003
                Last_IO_Error: error connecting to master 'rep@master2:3306' - retry-time: 60  retries: 4
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 0
                  Master_UUID: 
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 221015 02:49:20
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: 20555f91-4ad8-11ed-a8ff-000c299c92f3:1-4
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

现在测试一下maser1和master2是否可以同步，双主是否设置成功

//在master1的数据库中插入数据，在master2中查看数据
//master1
mysql> insert into master1db.tab1 values(123123);
Query OK, 1 row affected (0.01 sec)

//master2
mysql> select * from master1db.tab1;
+--------+
| name   |
+--------+
| 111    |
| 222    |
| 333    |
| 444    |
| 555    |
| 666    |
| 7777   |
| 8888   |
| 999    |
| 1010   |
| 123123 |
+--------+
11 rows in set (0.00 sec)

//在master2的数据库中插入数据，在master1数据库中查看
//master2
mysql> insert into master1db.tab1 values(789789);
Query OK, 1 row affected (0.01 sec)

//master1
mysql> select * from master1db.tab1;
+--------+
| name   |
+--------+
| 111    |
| 222    |
| 333    |
| 444    |
| 555    |
| 666    |
| 7777   |
| 8888   |
| 999    |
| 1010   |
| 123123 |
| 789789 |
+--------+
12 rows in set (0.00 sec)
//这里遇到一个问题，就是在master2中插入数据之后，在master1中并没有同步过来，有可能是因为前面临时关闭了二进制日志，后面没有开启二进制日志，我退出了一下数据库，重新进了一下，再插入数据，就同步了

• 从操作

//先备份一下master1的当前状态，然后把备份复制到slave
[root@master1 ~]# mysqldump -p'Qian@123' --all-databases --single-transaction --master-data=2 --flush-logs > `date +%F-%H`-mysql-all.sql
[root@master1 ~]# scp 2022-10-15-03-mysql-all.sql slave1:/tmp
root@slave1's password: 
2022-10-15-03-mysql-all.sql                        100%  861KB  28.7MB/s   00:00    
[root@master1 ~]# scp 2022-10-15-03-mysql-all.sql slave2:/tmp

slave1

//清一下slave1环境
//启动从服务器ID,GTID
[root@slave1 ~]# mysql -p'Linn@123' < /tmp/mmss-mysql-all.sql
[root@slave1 ~]# vim /etc/my.cnf
[mysqld]
server_id=3
gtid_mode=ON
enforce_gtid_consistency=1
master-info-repository=TABLE
relay-log-info-repository=TABLE    //中继日志
[root@slave1 ~]# systemctl restart mysqld

//设置主服务器
[root@slave1 ~]# mysql -p'Linn@123'
mysql> source /tmp/2022-10-15-03-mysql-all.sql
mysql> change master to
    -> master_host='master1',
    -> master_user='rep',
    -> master_password='Qian@123',
    -> master_auto_position=1 for channel 'master1';

mysql> change master to 
    -> master_host='master2',
    -> master_user='rep',
    -> master_password='Qian@123',
    -> master_auto_position=1 for channel 'master2';
Query OK, 0 rows affected, 2 warnings (0.01 sec)

mysql> start slave;
Query OK, 0 rows affected (0.00 sec)

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: 
                  Master_Host: master1
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: 
          Read_Master_Log_Pos: 4
               Relay_Log_File: slave1-relay-bin-master1.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: 
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              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: 0
              Relay_Log_Space: 154
              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: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 1236
                Last_IO_Error: 0
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 1
                  Master_UUID: 20555f91-4ad8-11ed-a8ff-000c299c92f3
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 221015 04:14:36
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: d9c78455-4c5e-11ed-9059-000c29c7c574:1
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: master1
           Master_TLS_Version: 
*************************** 2. row ***************************
               Slave_IO_State: 
                  Master_Host: master2
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: 
          Read_Master_Log_Pos: 4
               Relay_Log_File: slave1-relay-bin-master2.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: 
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              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: 0
              Relay_Log_Space: 154
              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: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 1236
                Last_IO_Error: 0
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 2
                  Master_UUID: 79050a0d-4c52-11ed-b6ff-000c29fcfb13
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 221015 04:14:36
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: d9c78455-4c5e-11ed-9059-000c29c7c574:1
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: master2
           Master_TLS_Version: 
2 rows in set (0.00 sec)

slave2

//启动从服务器ID,GTID
[root@slave2 ~]# vim /etc/my.cnf
[mysqld]
server_id=4
gtid_mode=ON
enforce_gtid_consistency=1
master-info-repository=TABLE
relay-log-info-repository=TABLE
[root@slave2 ~]# systemctl restart mysqld

//设置主服务器
[root@slave2 ~]# mysql -p'Qian@1234'
mysql> source /tmp/2022-10-15-03-mysql-all.sql
mysql> change master to
    -> master_host='master1',
    -> master_user='rep',
    -> master_password='Qian@123',
    -> master_auto_position=1 for channel 'master1';
Query OK, 0 rows affected, 2 warnings (0.03 sec)

mysql> change master to
    -> master_host='master2',
    -> master_user='rep',
    -> master_password='Qian@123',
    -> master_auto_position=1 for channel 'master2';
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave;
Query OK, 0 rows affected (0.02 sec)

最后在主服务器数据库中插入数据，查看从服务器就可以看到数据已经同步