從庫生成兩個線程，一個I/O線程，一個SQL線程；

i/o線程去請求主庫 的binlog，并將得到的binlog日志寫到relay log（中繼日志） 文件中；

主庫會生成一個 log dump 線程，用來給從庫 i/o線程傳binlog；

SQL 線程，會讀取relay log文件中的日志，并解析成具體操作，來實現主從的操作一致，而最終數據一致；

規劃

centos7.6

mysql-5.7.17.tar

mysql-proxy-0.8.5-linux-debian6.0-x86-64bit.tar.gz

mysql01 主 mysql02從 mysql03 讀寫分離 mysql04測試機

mysql搭建

1.解壓

[root@mysql01 ~]# ls
anaconda-ks.cfg  mysql-5.7.17.tar
[root@mysql01 ~]# tar -xvf mysql-5.7.17.tar 
./mysql-community-client-5.7.17-1.el7.x86_64.rpm
./mysql-community-common-5.7.17-1.el7.x86_64.rpm
./mysql-community-devel-5.7.17-1.el7.x86_64.rpm
./mysql-community-embedded-5.7.17-1.el7.x86_64.rpm
./mysql-community-embedded-compat-5.7.17-1.el7.x86_64.rpm
./mysql-community-embedded-devel-5.7.17-1.el7.x86_64.rpm
./mysql-community-libs-5.7.17-1.el7.x86_64.rpm
./mysql-community-libs-compat-5.7.17-1.el7.x86_64.rpm
./mysql-community-minimal-debuginfo-5.7.17-1.el7.x86_64.rpm
./mysql-community-server-5.7.17-1.el7.x86_64.rpm
./mysql-community-test-5.7.17-1.el7.x86_64.rpm

2.安裝

[root@mysql01 ~]# ls
anaconda-ks.cfg
mysql-5.7.17.tar
mysql-community-client-5.7.17-1.el7.x86_64.rpm    #安裝
mysql-community-common-5.7.17-1.el7.x86_64.rpm    #安裝
mysql-community-devel-5.7.17-1.el7.x86_64.rpm  
mysql-community-embedded-5.7.17-1.el7.x86_64.rpm
mysql-community-embedded-compat-5.7.17-1.el7.x86_64.rpm
mysql-community-embedded-devel-5.7.17-1.el7.x86_64.rpm
mysql-community-libs-5.7.17-1.el7.x86_64.rpm      #安裝
mysql-community-libs-compat-5.7.17-1.el7.x86_64.rpm  #安裝
mysql-community-minimal-debuginfo-5.7.17-1.el7.x86_64.rpm
mysql-community-server-5.7.17-1.el7.x86_64.rpm   #安裝
mysql-community-test-5.7.17-1.el7.x86_64.rpm

[root@mysql01 ~]#yum install -y mysql-community-client-5.7.17-1.el7.x86_64.rpm mysql-community-common-5.7.17-1.el7.x86_64.rpm mysql-community-libs-5.7.17-1.el7.x86_64.rpm mysql-community-libs-compat-5.7.17-1.el7.x86_64.rpm mysql-community-server-5.7.17-1.el7.x86_64.rpm

3.啟動mysql服務

[root@mysql01 ~]# systemctl start mysqld
[root@mysql01 ~]# cat /var/log/mysqld.log | grep password
2022-03-11T13:48:31.592028Z 1 [Note] A temporary password is generated for root@localhost: +i2yM_qvqtxj

4 修改密碼，否則不能正常使用

[root@mysql01 ~]# mysql_secure_installation

Securing the MySQL server deployment.

Enter password for user root: 初始密碼

The existing password for the user account root has expired. Please set a new password.

New password:  新密碼

Re-enter new password: 再次輸入新密碼

Re-enter new password: 
The 'validate_password' plugin is installed on the server.
The subsequent steps will run with the existing configuration
of the plugin.
Using existing password for root.

Estimated strength of the password: 100 
Change the password for root ? ((Press y|Y for Yes, any other key for No) : 

 ... skipping.
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.

Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.


Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.

Disallow root login remotely? (Press y|Y for Yes, any other key for No) : y
Success.

By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.


Remove test database and access to it? (Press y|Y for Yes, any other key for No) : y
 - Dropping test database...
Success.

 - Removing privileges on test database...
Success.

Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.

Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.

All done!

5 登錄mysql

[root@mysql01 ~]# mysql -uroot -p123qqq...A
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 6
Server version: 5.7.17 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

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>

主從搭建

mysql01和mysql02完成以上數據庫部署

1 mysql01主操作

[root@mysql01 ~]# vim /etc/my.cnf
log-bin=mysql-bin  # 啟用二進制功能，主從復制基礎
server-id=1        # id唯一
[root@mysql01 ~]# systemctl restart mysqld

2 驗證配置是否生效

mysql> show variables like "server_id";
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 1     |  #為配置文件配置的server_id
+---------------+-------+
1 row in set (0.01 sec)
mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin       | ON    |  #為on
+---------------+-------+
1 row in set (0.00 sec)
mysql> show variables like '%skip_networking%';
#skip_networking默認是OFF關閉狀態，啟用后主從將無法通信
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| skip_networking | OFF   |
+-----------------+-------+
1 row in set (0.00 sec)

3 mysql02從服務器操作

[root@mysql02 ~]# vim /etc/my.cnf
server-id=3  添加  
[root@mysql02 ~]# systemctl restart mysqld

4 驗證配置是否生效

mysql> show variables like "server_id";
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 3     |
+---------------+-------+
1 row in set (0.01 sec)

5 gitd實現主從同步

相比于傳統的主從復制優點：不需要知道復制哪個文件，也不需要知道從哪個號開始復制 ?

?5.1 mysql01?

[root@mysql01 ~]# vim /etc/my.cnf
gtid_mode =ON
enforce-gtid-consistency=true
[root@mysql01 ~]# systemctl restart mysqld

mysql> grant replication slave on *.* to repl@'192.168.226.%' identified by '123qqq...A';
Query OK, 0 rows affected, 1 warning (0.00 sec)
#  為服務器創建一個連接賬戶并授予權限，*.*表示所有權限;192.168.226.%表示這個網段的所有用戶都有這個權限

mysql> show master status;
+------------------+----------+--------------+------------------+----------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                      |
+------------------+----------+--------------+------------------+----------------------------------------+
| mysql-bin.000002 |      449 |              |                  | f02849a0-a141-11ec-a0a1-000c29a6904c:1 |
+------------------+----------+--------------+------------------+----------------------------------------+
1 row in set (0.00 sec)

5.2 mysql02

[root@mysql02 ~]# vim /etc/my.cnf
gtid_mode =ON
enforce-gtid-consistency=true
[root@mysql02 ~]# systemctl restart mysqld

mysql> change master to master_host='192.168.226.127',master_user='repl',master_password='123qqq...A',MASTER_AUTO_POSITION=1;
Query OK, 0 rows affected, 2 warnings (0.09 sec)
# 改變slave服務器用于連接master服務器的參數，此處把MASTER值設為動態
mysql> start slave ;
mysql> show slave status G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.226.127
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000002
          Read_Master_Log_Pos: 449
               Relay_Log_File: mysql02-relay-bin.000002
                Relay_Log_Pos: 662
        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: 449
              Relay_Log_Space: 871
              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: f02849a0-a141-11ec-a0a1-000c29a6904c
             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: f02849a0-a141-11ec-a0a1-000c29a6904c:1
            Executed_Gtid_Set: f02849a0-a141-11ec-a0a1-000c29a6904c:1
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

change master to master_host='192.168.226.127',master_user='repl',master_password='123qqq...A',master_log_file='mysql-bin.000002',master_log_pos=449;
不用gitd用這個命令

測試

mysql01

mysql> create database test;
Query OK, 1 row affected (0.00 sec)

mysql> use test;

mysql> create table tese01(name varchar(10) not null, age varchar(5) not null);
Query OK, 0 rows affected (0.03 sec)

mysql> insert into tese01 values("tom","18")；

mysql> select * from tese01;
+------+-----+
| name | age |
+------+-----+
| tom  | 18  |
+------+-----+
1 row in set (0.00 sec)

mysql02

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

mysql> use test;
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_test |
+----------------+
| tese01         |
+----------------+
1 row in set (0.00 sec)

mysql> select * from tese01;
+------+-----+
| name | age |
+------+-----+
| tom  | 18  |
+------+-----+
1 row in set (0.01 sec)

mysql-proxy安裝

mysql03

[root@mysql03 ~]# ls
anaconda-ks.cfg  mysql-5.7.17.tar  mysql-proxy-0.8.5-linux-debian6.0-x86-64bit.tar.gz
[root@mysql03 ~]# tar -zxvf mysql-proxy-0.8.5-linux-debian6.0-x86-64bit.tar.gz
[root@mysql03 ~]# mv mysql-proxy-0.8.5-linux-debian6.0-x86-64bit /usr/local/mysql-proxy
[root@mysql03 ~]# cd /usr/local/mysql-proxy/
[root@mysql03 mysql-proxy]# ls
bin  include  lib  libexec  licenses  share
[root@mysql03 mysql-proxy]# mkdir conf logs
[root@mysql03 mysql-proxy]# cd conf/
[root@mysql03 conf]# vim mysql-proxy.conf
[mysql-proxy]
 user=root   運行mysql-proxy用戶
 proxy-address=0.0.0.0:3306  
 proxy-backend-addresses=172.25.44.1:3306 #指定后端主master寫入數據
 proxy-read-only-backend-addresses=172.25.44.2:3306  #指定后端從slave讀取數據
 proxy-lua-script=/usr/local/mysql-proxy/share/doc/mysql-proxy/rw-splitting.lua    #指定讀寫分離配置文件位置
 log-file=/usr/local/mysql-proxy/logs/mysql-proxy.log    #日志位置
 log-level=debug  #定義log日志級別，由高到低分別有(error|warning|info|message|debug)

[root@mysql03 conf]#chmod 660 /usr/local/mysql-proxy/conf/mysql-proxy.conf
[root@mysql03 conf]#mysql-proxy --defaults-file=/usr/local/mysql-proxy/conf/mysql-proxy.conf

測試

mysql01

mysql> grant  all privileges on *.* to root@'%' identified by'123qqq...A'；

mysql04

[root@mysql04 ~]# yum install mysql -y
[root@mysql04 ~]# mysql -h 192.168.226.129 -uroot -p123qqq...A
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MySQL connection id is 14
Server version: 5.7.17-log MySQL Community Server (GPL)

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MySQL [(none)]>

驗證

mysql01數據庫建庫建表，在mysql04上可以查看到。

mysql03自動抓包

[root@mysql03 conf]# mysql-proxy --defaults-file=/usr/local/mysql-proxy/conf/mysql-proxy.conf
    server default db: 
    client default db: test
    syncronizing

原文鏈接：
https://www.tuicool.com/articles/6jmyQvi