文档课题：rhel 7.3搭建mysql的主从复制—非单机场景.
数据库：mysql 8.0.27
系统：rhel 7.3
安装包：mysql-8.0.27-linux-glibc2.12-x86_64.tar.xz
环境介绍：
1、理论知识
master将操作语句记录到binlog日志，然后授予slave远程连接权限(master需开启binlog，为数据安全考虑，slave也开启binlog）.
slave开启IO线程和SQL线程，其中IO线程负责读取master的binlog到中继日志；SQL线程负责从中继日志读出binlog内容，并更新到slave的数据库里，如此保证slave和master数据一致性.
Mysql复制至少需要两个Mysql服务，当然Mysql服务可以分布在不同的服务器上，也可以分布在一台服务器上，此次测试Mysql在不同的服务器上.master和slave两节点间时间需同步.
2、开始搭建
2.1、安装mysql
准备两台安装好mysql 8.0.27的服务器.
2.2、主库配置
2.2.1、修改配置文件
--修改主节点配置文件
[root@leo-mysql-master etc]# vi /etc/my.cnf
添加如下内容：
log_bin=master_bin --开启二进制
server_id=1 --设置当前节点全局唯一ID，后续在创建连接时需要该参数.
2.2.2、重启mysql服务
[root@leo-mysql-master etc]# service mysql stop
Shutting down MySQL. SUCCESS!
[root@leo-mysql-master etc]# service mysql start
Starting MySQL. SUCCESS!
[root@leo-mysql-master etc]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.27 MySQL Community Server - GPL
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show master status \G
*************************** 1. row ***************************
File: master_bin.000001
Position: 957
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.01 sec)
2.2.3、创建复制用户
创建复制用户账号，192.168.133.%表示允许IP前边是192.168.133的repluser用户连接master主机.
mysql> create user repluser@'192.168.133.%' identified by '123456';
Query OK, 0 rows affected (0.01 sec)
授权用户
mysql> grant replication slave, replication client on *.* to repluser@'192.168.133.%';
Query OK, 0 rows affected (0.00 sec)
2.3、从库配置
2.3.1、修改配置文件
[root@leo-mysql-slave etc]# cp /etc/my.cnf /etc/my_bak.cnf
[root@leo-mysql-slave etc]# vi /etc/my.cnf
添加如下：
server_id=2 --当前节点全局性ID号
log-bin=slave_log --开启二进制日志
read_only=ON --设置从库只读，对root用户无效
relay_log=relay-log --relay log的文件路径
relay_log_index=relay-log.index -默认值hostname-relay-bin.index
2.3.2、重启mysql服务
重启从库mysql服务.
[root@leo-mysql-slave etc]# service mysql stop
Shutting down MySQL.. SUCCESS!
[root@leo-mysql-slave etc]# service mysql start
Starting MySQL. SUCCESS!
2.3.3、启动复制线程
从库使用有复制权限的用户连接至主库，并启动复制线程
[root@leo-mysql-slave etc]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.27 MySQL Community Server - GPL
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> change master to master_host='192.168.133.111',master_user='repluser',master_password='123456',master_log_file='master_bin.000001',MASTER_LOG_POS=957;
Query OK, 0 rows affected, 8 warnings (0.02 sec)
mysql> start slave;
Query OK, 0 rows affected, 1 warning (0.01 sec)
2.3.4、查看状态
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for source to send event
Master_Host: 192.168.133.111
Master_User: repluser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: master_bin.000001
Read_Master_Log_Pos: 957
Relay_Log_File: relay-log.000002
Relay_Log_Pos: 325
Relay_Master_Log_File: master_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: 957
Relay_Log_Space: 528
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: 3393dd41-fb9f-11ed-a80f-000c291140b1
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Replica 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: 1
Network_Namespace:
1 row in set, 1 warning (0.00 sec)
mysql> show warnings;
+---------+------+-------------------------------------------------------------------------------------------------------------------+
| Level | Code | Message |
+---------+------+-------------------------------------------------------------------------------------------------------------------+
| Warning | 1287 | 'SHOW SLAVE STATUS' is deprecated and will be removed in a future release. Please use SHOW REPLICA STATUS instead |
+---------+------+-------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
3、数据测试
3.1、建测试数据
现在主库上创建测试库booksDB，然后创建表books并插入记录.测试数据是否会同步到两个从库.
mysql> create database booksDB;
Query OK, 1 row affected (0.00 sec)
mysql> use booksDB;
Database changed
mysql> create table books
-> (
-> bk_id int not null primary key,
-> bk_title varchar(50) not null,
-> copyright year not null
-> );
Query OK, 0 rows affected (0.00 sec)
mysql> insert into books values
-> (11078,'Learning MYSQL',2010),
-> (11033,'Study Html',2011),
-> (11035,'How to use php',2003),
-> (11072,'Teach yourself javascript',2005),
-> (11028,'Learning C++',2005),
-> (11069,'MYSQL professional',2009),
-> (11026,'Guide to MySQL 5.7',2008),
-> (11041,'Inside VC++',2011);
Query OK, 8 rows affected (0.01 sec)
Records: 8 Duplicates: 0 Warnings: 0
mysql> select * from books;
+-------+---------------------------+-----------+
| bk_id | bk_title | copyright |
+-------+---------------------------+-----------+
| 11026 | Guide to MySQL 5.7 | 2008 |
| 11028 | Learning C++ | 2005 |
| 11033 | Study Html | 2011 |
| 11035 | How to use php | 2003 |
| 11041 | Inside VC++ | 2011 |
| 11069 | MYSQL professional | 2009 |
| 11072 | Teach yourself javascript | 2005 |
| 11078 | Learning MYSQL | 2010 |
+-------+---------------------------+-----------+
8 rows in set (0.00 sec)
3.2、验证数据
在从库执行以下命令，查看数据是否已经同步.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| booksDB |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)
mysql> use booksDB
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+-------------------+
| Tables_in_booksDB |
+-------------------+
| books |
+-------------------+
1 row in set (0.00 sec)
mysql> select * from books;
+-------+---------------------------+-----------+
| bk_id | bk_title | copyright |
+-------+---------------------------+-----------+
| 11026 | Guide to MySQL 5.7 | 2008 |
| 11028 | Learning C++ | 2005 |
| 11033 | Study Html | 2011 |
| 11035 | How to use php | 2003 |
| 11041 | Inside VC++ | 2011 |
| 11069 | MYSQL professional | 2009 |
| 11072 | Teach yourself javascript | 2005 |
| 11078 | Learning MYSQL | 2010 |
+-------+---------------------------+-----------+
8 rows in set (0.00 sec)
mysql> show replica status \G
*************************** 1. row ***************************
Replica_IO_State: Waiting for source to send event
Source_Host: 192.168.133.111
Source_User: repluser
Source_Port: 3306
Connect_Retry: 60
Source_Log_File: master_bin.000001
Read_Source_Log_Pos: 1897
Relay_Log_File: relay-log.000002
Relay_Log_Pos: 1265
Relay_Source_Log_File: master_bin.000001
Replica_IO_Running: Yes
Replica_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_Source_Log_Pos: 1897
Relay_Log_Space: 1468
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Source_SSL_Allowed: No
Source_SSL_CA_File:
Source_SSL_CA_Path:
Source_SSL_Cert:
Source_SSL_Cipher:
Source_SSL_Key:
Seconds_Behind_Source: 0
Source_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Source_Server_Id: 1
Source_UUID: 3393dd41-fb9f-11ed-a80f-000c291140b1
Source_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Replica_SQL_Running_State: Replica has read all relay log; waiting for more updates
Source_Retry_Count: 86400
Source_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Source_SSL_Crl:
Source_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Source_TLS_Version:
Source_public_key_path:
Get_Source_public_key: 1
Network_Namespace:
1 row in set (0.00 sec)
说明：如上所示，主节点数据成功同步到从节点.
参考网址：
https://blog.csdn.net/weixin_46780832/article/details/129657998
https://blog.csdn.net/weixin_45648789/article/details/129125997
