实现MySQL8.0.25集群主从复制

Posted 2021-06-08 白-胖-子

mysql集群

• 避免单点故障
• 负载均衡读写分离
• 主从复制依赖于二进制日志
• 主从节点版本应该一直，如不一致，从节点应用高版本

主从复制原理

• 主开启一个线程监听并传递修改
• 从节点开启两个线程，接受修改，完成修改

配置实现MySQL主从复制

主节点配置

• 确认启用二进制日志，把二进制文件放在独立的目录中
• 分配ID号，默认是1，修改配置文件/etc/my.cnf
  建议使用ip地址的主机位最后一位作为server-ID 避免ID冲突
• 确定二进制日志文件位置和二进制日志中所在位置
• 创建有复制权限的账号
  MySQL8.0分成两步实现

从节点配置

• 确认启用二进制日志
• 从节点设置和主节点不同的ID号
• 从数据库开启只读模式

配置实现

• 主节点配置服务器配置文件my.cnf

[root@C8-183 ~]# cat /etc/my.cnf 
[mysqld]
server-id=183 ##确保唯一的ID号
#log-bin
log-bin=/data/mysql/mysql-bin ## 独立存放的二进制日志
datadir=/data/mysql
socket=/data/mysql/mysql.sock
log-error=/data/mysql/mysql.log
pid-file=/data/mysql/mysql.pid
[client]
socket=/data/mysql/mysql.sock

• 在mysel内创建专门用于复制的用户并赋权

mysql> create user 'cper'@'10.0.0.%' identified by 'bbbbbbbb';
Query OK, 0 rows affected (0.01 sec)

mysql> grant replication slave on *.* to 'cper'@'10.0.0.%';
Query OK, 0 rows affected (0.01 sec)

• 查看当前二进制日志所记录的条目

mysql> show master logs;
+------------------+-----------+-----------+
| Log_name         | File_size | Encrypted |
+------------------+-----------+-----------+
| mysql-bin.000001 |       179 | No        |
| mysql-bin.000002 |       949 | No        |
+------------------+-----------+-----------+
2 rows in set (0.00 sec)

• 从节点配置服务器配置文件my.cnf

[root@C8-185 ~]# cat /etc/my.cnf 
[mysqld]
server-id=185 ##确保唯一的ID号
#read-only ##开启只读模式
read_only=ON #设置数据库只读，针对supper user无效
relay_log=relay-log #relay log的文件路径，默认值hostname-relay-bin
relay_log_index=relay-log.index #默认值hostname-relay-bin.index
#log-bin
log-bin=/data/mysql/mysql-bin ## 独立存放的二进制日志
datadir=/data/mysql
socket=/data/mysql/mysql.sock
log-error=/data/mysql/mysql.log
pid-file=/data/mysql/mysql.pid
[client]
socket=/data/mysql/mysql.sock

• 进入从节点MySQL服务器
• 使用有复制权限的用户账号连接至主服务

mysql> change master to master_host='10.0.0.183', ##连接至主服务器IP
    -> master_user='cper',## 主服务器创建的专门复制用的账号
    -> master_password='aaaaaaaa',## 专用复制账号的密码
    -> master_log_file='mysql-bin.000002', ## 二进制日志文件名
    -> master_log_pos=949; ## 记录条目
Query OK, 0 rows affected, 8 warnings (0.01 sec)

• 启动复制线程

mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.01 sec)

查看从节点监听状态

mysql> show slave status\\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.183
                  Master_User: cper
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000002
          Read_Master_Log_Pos: 949
               Relay_Log_File: relay-log.000002
                Relay_Log_Pos: 324
        Relay_Master_Log_File: mysql-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: 949
              Relay_Log_Space: 527
              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: 183
                  Master_UUID: 811da04d-b7bd-11eb-b225-000c29d2606b
             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: 
     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)

测试集群主从是否同步

初始状态查看

主节点导入数据库

mysql> system wget 10.0.0.88/mysql/hellodb_innodb.sql
--2021-05-18 18:32:26--  http://10.0.0.88/mysql/hellodb_innodb.sql
Connecting to 10.0.0.88:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 7786 (7.6K) [application/sql]
Saving to: ‘hellodb_innodb.sql’

hellodb_innodb.sql         100%[======================================>] 

2021-05-18 18:32:26 (1.08 GB/s) - ‘hellodb_innodb.sql’ saved [7786/7786]

mysql> system ls;
anaconda-ks.cfg  hellodb_innodb.sql  original-ks.cfg
mysql> source /root/hellodb_innodb.sql
Query OK, 0 rows affected (0.01 sec

从节点查看数据库

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| hellodb            |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

同步成功

![主从复制成功](https://img-blog.csdnimg.cn/20210518183443546.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpbW9uaXVt,size_16,color_FFFFFF,t_70)