环境简介

主服务器：JD云 CentOS

从服务器：Vultr云 CentOS

为了方便测试，都使用Docker运行Mysql，Docker启动命令如下：

 docker run --name mysql-server-01 -p 3306:3306 -v "$PWD"/conf.d:/etc/mysql/conf.d -v /my/own/datadir:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw  -d mysql:latest

以上均把mysql配置目录和data目录映射到了宿主机。

配置Master

为了方便，专门建一个目录用来操作master数据库，结构如下

mysql
└── server01
    ├── conf.d
    ├── data
    └── start.sh

在cond.d建立my.cnf用来配置master

[mysqld]
log-bin=mysql-bin
server-id=1
innodb_flush_log_at_trx_commit=1
sync_binlog=1

然后就可以启动容器了。

启动后，进入容器操作mysql

# 进入容器
docker exec -it 容器ID bash

# 进入msyql客户端
mysql -u root -p

# 新建salve用户并配置权限，格式如下
mysql> CREATE USER 'repl'@'%.example.com' IDENTIFIED BY 'password';
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%.example.com';

# 查看master状态，这里file和position后面配置salve会用到

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |     1092 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

配置slave服务器

slave my.cnf配置文件如下（这里为了简便，省去很多参数，勿用于生产环境）：

[mysqld]
server-id=2

然后启动容器，进入mysql客户端。

# 配置master到slave
mysql> CHANGE MASTER TO
    ->     MASTER_HOST='master_host_name',
    ->     MASTER_USER='replication_user_name',
    ->     MASTER_PASSWORD='replication_password',
    ->     MASTER_LOG_FILE='recorded_log_file_name',
    ->     MASTER_LOG_POS=recorded_log_position;

上面的MASTER_LOG_FILE和MASTER_LOG_POS就是前面show master stuas 看到的file和position

然后启动slave

START SLAVE;

查看运行状态：

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: xxx.com
                  Master_User: slave1
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 1092
               Relay_Log_File: ca210e4caaaa-relay-bin.000002
                Relay_Log_Pos: 813
        Relay_Master_Log_File: mysql-bin.000001
             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: 1092
              Relay_Log_Space: 1027
              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: 5c2073ab-0ad6-11e8-a871-0242ac110005
             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)

上面Slave_IO_Running和Slave_SQL_Running都为YES，说明主从已经配置好了。

总结

mysql常见架构有三种

• 单实例架构
• 主从复制
• MHA高可用架构

其中主从复制一种是基于上面的binary log复制的方式，还有一种是基于全局事务标识（GTID）的方式。

后续我会调研MHA架构的实现。基于Docker的mysql主从复制