MySQL主从复制原理与配置

server-id=1                         # 设置 id，这个可以是任意数字
log-bin=/mydata/log/master-bin      # 启动 binlog 日志，名字必须是 log-bin
sync_binlog=1                       # 确保主从复制的事务安全

server-id=2                          # 这个 id 随便给，但不要和 master 的一样
relay-log=/mydata/log/slave-relay    # 这里是 relay-log 了，名字必须是 relay-log，备份的名字也就 slave-relay
sync_binlog=1
read-only=ON                         # 开启只读模式，确保主备数据一致

CHANGE MASTER TO
  MASTER_HOST='192.168.75.20',    # master IP
  MASTER_USER='slave',    # master 上创建专门用于备份的用户
  MASTER_PASSWORD='6yhn^YHN',    # 及其密码
  MASTER_PORT=3306,    # 从这行开始，都可以不输入，只要上面几行即可开启备份（而且最好不要设置，要不然会挖坑）
  MASTER_LOG_FILE='master-bin.000002',    # master 上 mysql 执行 show master status \G 查到的 File
  MASTER_LOG_POS=602,    # master 上 mysql 执行 show master status \G 查到的 Position
  MASTER_CONNECT_RETRY=10;    # 设置超时时间，超过 n 秒没连接上，则表示 master 挂了

start slave; 

	show slave status\G
    *************************** 1. row ***************************
                   Slave_IO_State: Waiting for master to send event
                      Master_Host: 192.168.75.20
                      Master_User: slave
                      Master_Port: 3306
                    Connect_Retry: 60
                  Master_Log_File: master-bin.000002
              Read_Master_Log_Pos: 602
                   Relay_Log_File: slave-relay.000003
                    Relay_Log_Pos: 817
            Relay_Master_Log_File: master-bin.000002
                 Slave_IO_Running: Yes                                  # 这里两个 Yes，则表示连接上了
                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: 602
                  Relay_Log_Space: 1235
                  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: d94faa39-e098-11ea-9c51-000c29823fb8
                 Master_Info_File: /mydata/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)