MySQL数据同步方式:

Synchronous Replication 同步复制

Asynchronous Replication 异步复制

Semisynchronous Replication 半同步复制 

    

    同步复制:指的是客户端连接到MySQL主服务器写入一段数据,MySQL主服务器同步给MySQL从服务器需要等待从服务器发出同步完成的响应才返回客户端OK, 这其中等待同步的过程是阻塞的, 如果有N台从服务器, 效率极低 

    异步复制: 指的是客户端连接到MySQL主服务器写入一段数据,MySQL主服务器将写入的数据发送给MySQL从服务器, 然后直接返回客户端OK, 可能从服务器的数据会和主服务不一致 

    半同步复制:指的是客户端连接到MySQL主服务器写入一段数据, MySQL主服务器只将数据同步复制给其中一台从服务器, 半同步复制给其他的从服务器, 来达到其中一台从服务器完全同步的效果



MySQL复制原理

wKiom1g7oYaTW1zxAACoZKVTYhE643.png

建立主从关系后, 主服务器如果有数据修改之后, BINLOG会更新, 从服务通过IO-Thread读取主服务器的BINLOG到本地的Relay Log, 再通过SQL-Thread对其进行重放(replay), 从而同步到本地




MySQL简单复制

拓扑:

wKiom1g7pLSzqQywAAA2VyrfGxc968.png


Master配置文件

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

symbolic-links=0
skip_name_resolve = ON
innodb_file_per_table = ON

server_id=1                 #主服务器ID
log_bin=master-bin             #开启二进制日志

[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid

!includedir /etc/my.cnf.d


Slave配置文件

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

symbolic-links=0

skip_name_resolve = ON
innodb_file_per_table = ON

server_id=2         #从服务器ID
relay_log=relay-log #开启中继日志

[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid

!includedir /etc/my.cnf.d


在主Master上面查看当前正在使用的二进制日志,并记录下position

MariaDB [(none)]> SHOW MASTER STATUS;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| master-bin.000003 |      245 |              |                  |
+-------------------+----------+--------------+------------------+
1 row in set (0.00 sec)


主Master上创建用户并赋予权限

MariaDB [(none)]> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'cpuser'@'10.1.%.%' IDENTIFIED BY '
userpass';
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)


配置Slave

MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='10.1.72.100',MASTER_USER='cpuser',MASTER_PASSWORD='userpass',MASTER_LOG_FILE='master-bin.000001',MASTER_LOG_POS=245;
Query OK, 0 rows affected (0.03 sec)

MariaDB [(none)]> SLAVE START;               #启动IO和SQL  Thread
Query OK, 0 rows affected (0.02 sec)

MariaDB [(none)]> SHOW SLAVE STATUS\G        #查看相应信息
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.1.72.100
                  Master_User: cpuser
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: master-bin.000001
          Read_Master_Log_Pos: 245
               Relay_Log_File: relay-log.000002
                Relay_Log_Pos: 530
        Relay_Master_Log_File: master-bin.000001
             Slave_IO_Running: Yes       #IO Thread已启动
            Slave_SQL_Running: Yes       #SQL Thread已启动
              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: 245
              Relay_Log_Space: 818
              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
1 row in set (0.00 sec)


测试:

在Master上创建一个数据库

wKiom1g7rUqjZZZsAAA1YJOxDOo413.png


Slave验证

wKioL1g7rXjCdt7dAAAiK3ngZj4822.png




主主复制配置

拓扑

wKiom1g73tGwhHfbAAA3_klsVmM499.png

互为主从:两个节点各自都要开启binlog和relay log


配置文件

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

symbolic-links=0

skip_name_resolve = ON
innodb_file_per_table = ON

server_id=1           #服务器ID
log_bin=mysql-bin     #开启二进制日志
relay_log=relay-log   #开启中继日志

auto_increment_offset=1
auto_increment_increment=2

[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid

!includedir /etc/my.cnf.d


都授权有复制全的用户账号,并把对方指定为主节点


Master1的配置

MariaDB [(none)]> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'cpuser'@'10.1.72.200' IDENTIFIED BY 'userpass';
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000003 |      506 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.01 sec)

MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='10.1.72.200',MASTER_USER='cpuser',MASTER_PASSWORD='userpass',MASTER_LOG_FILE='mysql-bin.000003',MASTER_LOG_POS=506;
Query OK, 0 rows affected (0.03 sec)


Master2的配置

MariaDB [(none)]> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'cpuser'@'10.1.72.100' IDENTIFIED BY 'userpass';
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='10.1.72.100',MASTER_USER='cpuser',MASTER_PASSWORD='userpass',MASTER_LOG_FILE='mysql-bin.000003',MASTER_LOG_POS=506;
Query OK, 0 rows affected (0.04 sec)

MariaDB [(none)]> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000003 |      506 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.01 sec)


在两个节点上同时启动IO和SQL Thread

MariaDB [(none)]> START SLAVE;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SHOW SLAVE STATUS\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.1.72.100
                  Master_User: cpuser
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 506
               Relay_Log_File: relay-log.000002
                Relay_Log_Pos: 529
        Relay_Master_Log_File: mysql-bin.000003
             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: 506
              Relay_Log_Space: 817
              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
1 row in set (0.00 sec)


验证

在Master1上创建数据库test1,可同步至Master2上,相反在Master2上创建test2也可同步至Master1

wKioL1g74JDCfUAuAAAzxp7FLW4235.png




半同步复制配置

拓扑

wKiom1g7402CWfW7AACPcKQ--sk722.png


半同步的插件在/usr/lib64/mysql/plugin下, master用的semisync_master.so,slave用的semisync_slave.so

配置Master

MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so';
Query OK, 0 rows affected (0.01 sec)

MariaDB [(none)]> SET GLOBAL rpl_semi_sync_master_enabled=1;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SET GLOBAL rpl_semi_sync_master_timeout=2000;
Query OK, 0 rows affected (0.00 sec)


配置Slave

MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so';
Query OK, 0 rows affected (0.03 sec)

MariaDB [(none)]> SET GLOBAL rpl_semi_sync_slave_enabled=1;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> STOP SLAVE;
Query OK, 0 rows affected (0.02 sec)

MariaDB [(none)]> START SLAVE;
Query OK, 0 rows affected (0.00 sec)


验证

wKiom1g76hqAp-koAABSZ78o1lM480.png