MySQL数据库主从复制原理及作用分析

#二进制安装：https://blog.csdn.net/qq_47945825/article/details/116848970?spm=1001.2014.3001.5501
#或者网络仓库安装：（一般二进制安装）
https://blog.csdn.net/qq_47945825/article/details/116245442?spm=1001.2014.3001.5501

[root@mysql01 ~]# mysql -uroot -e 'show databases;'
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
[root@mysql02 ~]# mysql -uroot -e 'show databases;'
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+

mysql> create user 'vvv'@'192.168.136.191' identified by 'vvv0917';
Query OK, 0 rows affected (0.00 sec)
mysql> grant replication slave on *.*to 'vvv'@'192.168.136.191';
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

[root@mysql02 ~]# mysql -uvvv -vvv0917 -h192.168.136.145
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
+--------------------+
1 row in set (0.00 sec)

[root@mysql01 ~]# cat /etc/my.cnf 
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
pid-file = /opt/data/mysql.pid
user = mysql
skip-name-resolve
log-bin=mysql_bin #启动binlog日志
server-id=10   #数据库服务器唯一标识，id必须比从数据库小
#重启服务 （此重启方式，前提已配置mysqld.service文件）
[root@mysql01 ~]# systemctl restart mysqld
观察主数据库状态：
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql_bin.000004 |      962 |              |                  |                   |
+------------------+----------+--------------+------------------+---

[root@mysql02 ~]# cat /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql 
datadir = /opt/data 
socket = /tmp/mysql.sock 
port = 3307
user = mysql
pid-file = /opt/data/mysql.pid
skip-name-resolve
#skip-grant-tables 
server-id=20               #服务器id，大于主数据库id
relay-log=mysql_relay_log  #启动中继日志
#log-bin=mysql-bin 
#重启服务：
[root@mysql02 ~]# systemctl restart mysqld

[root@slave02 ~]# mysql -uroot -p
mysql> change master to
    -> master_host='192.168.136.145',
    -> master_user='vvv',
    -> master_password='vvv0917',
    -> master_log_file='mysql_bin.000004',
    -> master_log_pos=962;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;   #stop slave为关闭
Query OK, 0 rows affected (0.01 sec)
#查看配置状态：
mysql> show slave status\G; 
   Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.136.145
                  Master_User: vvv
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_bin.000004
          Read_Master_Log_Pos: 962
               Relay_Log_File: mysql_relay_log.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql_bin.000004
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
            #此处必须俩个都是yes，就是配置成功，否则失败

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+

mysql> create database clq;
Query OK, 1 row affected (0.00 sec)
mysql> create table clq01(id int(11)not null primary key auto_increment,name varchar(100)not null,age tinyint(4)); 
mysql> insert clq01(name,age) values('A',20),('B',21),('C',22);
Query OK, 3 rows affected (0.00 sec)

mysql> select * from clq01;
+----+------+------+s
| id | name | age  |
+----+------+------s+
|  1 | A    |   20 |
|  2 | B    |   21 |
|  3 | C    |   22 |
+----+------+------+
                              #主从复制完成！

flush tables with read lock：
quit：退出即可为解锁（备份完之后才能解锁）

#先对主库进行全备
[root@mysql01 ~]# mysqldump -uroot -A > all-databases.sql 
#拷贝数据到从数据库上
[root@mysql01 ~]# ls /clq
all-databases.sql
[root@mysql01 ~]# scp /clq/all-databases.sql root@192.168.136.193:/clq/
The authenticity of host '192.168.136.193 (192.168.136.193)' can't be established.
ECDSA key fingerprint is SHA256:XIAQEoJ+M0vOHmCwQvhUdw12u5s2nvkN0A4TMKLaFiY.
Are you sure you want to continue connecting (yes/no/[fingerprint])yes
root@192.168.136.193's password: 
all-databases.sql                                                 100%  853KB 115.4MB/s   00:00  
[root@mysql02 clq]# ll
总用量 896                       #从库上查看
-rw-r--r--. 1 root root 873266 5月  17 19:36 all-databases.sql

[root@mysql02 clq]# mysql -uroot -pHuawei0917@ < all-databases.sql 
mysql: [Warning] Using a password on the command line interface can be insecure.
[root@mysql02 clq]# mysql -uroot -pHuawei0917@ -e 'show databases;'
mysql: [Warning] Using a password on the command line interface can be insecure.
+--------------------+
| Database           |
+--------------------+
| information_schema |
| clq                |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
主库：
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| clq                |
| mysql              |
| performance_schema |
| sys                |
+--------------------+

[root@mysql01 ~]# cat /etc/my.cnf 
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
pid-file = /opt/data/mysql.pid
user = mysql
skip-name-resolve
log-bin=mysql_bin     #日志文件
server-id=10          #唯一标识服务id
[root@mysql02 ~]# cat /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql 
datadir = /opt/data 
socket = /tmp/mysql.sock 
port = 3307
user = mysql
pid-file = /opt/data/mysql.pid
skip-name-resolve
#skip-grant-tables 
server-id=20                #唯一标识服务id（大于主库）
relay-log=mysql_relay_log     #中继日志
#log-bin=mysql-bin 

mysql> show processlist;
+----+------+-----------------------+------+-------------+------+---------------------------------------------------------------+------------------+
| Id | User | Host                  | db   | Command     | Time | State                                                         | Info             |
+----+------+-----------------------+------+-------------+------+---------------------------------------------------------------+------------------+
|  5 | repl | 192.168.136.219:39788 | NULL | Binlog Dump | 1575 | Master has sent all binlog to slave; waiting for more updates | NULL             |
|  7 | root | localhost             | NULL | Query       |    0 | starting                                                      | show processlist |
+----+------+-----------------------+------+-------------+------+---------------------------------------------------------------+------------------+
2 rows in set (0.00 sec)