2024.8.15（python管理mysql、Mycat实现读写分离）

一、python管理mysql

1、搭建主mysql

[root@mysql57 ~]# tar -xf mysql-5.7.44-linux-glibc2.12-x86_64.tar.gz 
[root@mysql57 ~]# cp -r mysql-5.7.44-linux-glibc2.12-x86_64 /usr/local/mysql
[root@mysql57 ~]# rm -rf /etc/my.cnf
[root@mysql57 ~]# mkdir /usr/local/mysql/mysql-files
[root@mysql57 ~]# useradd -r -s /sbin/nologin mysql
[root@mysql57 ~]# chown mysql:mysql /usr/local/mysql/mysql-files/
[root@mysql57 ~]# chown 750 /usr/local/mysql/mysql-files/
[root@mysql57 ~]# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql
[root@mysql57 ~]# ls /usr/local/mysql/
[root@mysql57 ~]# cp /usr/local/mysql/support-files/mysql.server
 /etc/init.d/mysql57
[root@mysql57 ~]# service mysql57 start
[root@mysql57 ~]# /usr/local/mysql/bin/mysql -p
Enter password: 

mysql> alter user 'root'@'localhost' identified by 'root';
Query OK, 0 rows affected (0.00 sec)mysql> create user 'blt'@'%' identified by 'blt';
Query OK, 0 rows affected (0.00 sec)mysql> grant all on *.* to 'blt'@'%';
Query OK, 0 rows affected (0.00 sec)mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)mysql> create database if not exists test charset utf8mb4;
Query OK, 1 row affected (0.00 sec)mysql> use test;
Database changed
mysql> create table user(id int primary key auto_increment,username varchar(45) not null,password varchar(45) not null);
Query OK, 0 rows affected (0.01 sec)mysql> insert into user (username,password)values("aaa","aaa");
Query OK, 1 row affected (0.02 sec)mysql> select * from user;
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  1 | aaa      | aaa      |
+----+----------+----------+
1 row in set (0.00 sec)

2、pymysql

[root@client ~]# python3 

>>> import pymysql
>>>conn=pymysql.connect(host="192.168.8.150",port=3306,database="test",user="blt",password="blt");
>>> cursor=conn.cursor()

3、修改root权限

mysql> update mysql.user set host='%' where user='root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

>>>conn=pymysql.connect(host="192.168.8.150",port=3306,database="test",user="root",password="root");
>>> curson=conn.cursor()
>>> cursor.execute("create user 'slave0'@'%' identified by 'slave0'")
0
>>> cursor.execute("grant replication slave on *.* to 'slave0'@'%'")
>>> cursor.execute("flush privileges")
>>> cursor.execute("flush tables with read lock")
0
>>> cursor.execute("unlock tables")
0
>>> cursor.execute("flush tables with read lock")
0
>>> cursor.execute("show master status")
0
>>> print(cursor.fetchall())
()
>>> cursor.execute("show master status")

4、my.cnf

[root@mysql57 ~]# rm -rf /etc/my.cnf

[root@mysql57 ~]# vim /usr/local/mysql/my.cnf

[mysqld]
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock
port=3306
log-error=/usr/local/mysql/data/db01-master.err
log-bin=/usr/local/mysql/data/binlog
server-id=10
character_set_server=utf8mb4

[root@mysql57 ~]# service mysql57 restart

>>> conn=pymysql.connect(host="192.168.8.150",port=3306,database="test",user="blt",password="blt");
>>> cursor=conn.cursor()
>>> cursor.execute("show master status")
1
>>> print(cursor.fetchall())
(('binlog.000001', 154, '', '', ''),)
>>> cursor.execute("unlock tables")
0

5、slave数据库

[root@slave57 ~]# tar -xf mysql-5.7.44-linux-glibc2.12-x86_64.tar.gz 
[root@slave57 ~]# cp -r mysql-5.7.44-linux-glibc2.12-x86_64 /usr/local/mysql
[root@slave57 ~]# ls /usr/local/mysql/
[root@slave57 ~]# mkdir /usr/local/mysql/mysql-files
[root@slave57 ~]# useradd -r -s /sbin/nologin mysql
[root@slave57 ~]# chown mysql:mysql /usr/local/mysql/mysql-files/
[root@slave57 ~]# chmod 750 /usr/local/mysql/mysql-files/

6、主从同步

[root@mysql57 ~]# rm -rf /usr/local/mysql/data/auto.cnf 
[root@mysql57 ~]# yum -y install rsync

[root@mysql57 ~]# rsync -av /usr/local/mysql/data root@192.168.8.151:/usr/local/mysql/

[root@slave57 ~]# yum -y install rsync

[root@slave57 ~]# vim /usr/local/mysql/my.cnf
[root@slave57 ~]# cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql57
[root@slave57 ~]# sed -i '$aexport PATH=$PATH:/usr/local/mysql/bin' /etc/profile
[root@slave57 ~]# sed -n '$p' /etc/profile
export PATH=$PATH:/usr/local/mysql/bin
[root@slave57 ~]# source /etc/profile
[root@slave57 ~]# chkconfig --add mysql57
[root@slave57 ~]# chkconfig mysql57
[root@slave57 ~]# chkconfig mysql57 on

7、错误

[root@slave57 ~]# service mysql57 start
Starting MySQL.2024-08-15T06:29:37.027747Z mysqld_safe error: log-error set to '/var/log/mariadb/mariadb.log', however file don't exists. Create writable for user 'mysql'.
 ERROR! The server quit without updating PID file (/usr/local/mysql/data/slave57.pid).

[root@slave57 ~]# mkdir /var/log/mariadb
[root@slave57 ~]# touch /var/log/mariadb/mariadb.log
[root@slave57 ~]# chown -R mysql:mysql /var/log/mariadb/
[root@slave57 ~]# service mysql57 start
Starting MySQL. SUCCESS! 

二、MyCat实现读写分离

1、添加新的虚拟主机，关闭防火墙

[root@mycat ~]# systemctl stop firewalld
[root@mycat ~]# setenforce 0

2、上传jdk和Mycat

[root@mycat ~]# ls

3、解压并上传到指定位置

[root@mycat ~]# tar -xf Mycat-server-1.6.5-release-20180122220033-linux.tar.gz 
[root@mycat ~]# tar -xf jdk-8u192-linux-x64.tar.gz 
[root@mycat ~]# cp -r jdk1.8.0_192/ /usr/local/jdk
[root@mycat ~]# cp -r mycat/ /usr/local/

4、查看并且配置jdk文件

[root@mycat ~]# ls /usr/local/jdk/

[root@mycat ~]# sed -i '$aexport JAVA_HOME=/usr/local/jdk' /etc/profile
[root@mycat ~]# source /etc/profile
[root@mycat ~]# $JAVA_HOME
-bash: /usr/local/jdk: 是一个目录
[root@mycat ~]# sed -i '$aexport PATH=$PATH:$JAVA_HOME/bin' /etc/profile
[root@mycat ~]# source /etc/profile

[root@mycat ~]# $PATH
-bash: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/jdk:/usr/local/jdk/bin: 没有那个文件或目录

[root@mycat ~]# javac -version
javac 1.8.0_192

5、测试启动Mycat

[root@mycat ~]# /usr/local/mycat/bin/mycat console

6、配置读写分离

[root@mycat logs]# vim /usr/local/mycat/conf/server.xml 

93         <user name="blt" defaultAccount="true">
94                 <property name="password">blt</property>
95                 <property name="schemas">test</property>
107 <!--
108         <user name="user">
109                 <property name="password">user</property>
110                 <property name="schemas">TESTDB</property>
111                 <property name="readOnly">true</property>
112         </user>
113 -->

[root@mycat logs]# vim /usr/local/mycat/conf/schema.xml  

4         <!-- 1.名称为真实数据库名称,添加一个dataNode-->
5         <schema name="test" dataNode="dn1" checkSQLschema="false" sqlMaxLimit="100">
6         </schema>
7         <!-- <dataNode name="dn1$0-743" dataHost="localhost1" database="db$0-743"
8                 /> -->
9         <dataNode name="dn1" dataHost="localhost1" database="test" />
20   <writeHost host="hostM1" url="192.168.8.150:3306" user="blt" password="blt">
21            <!-- can have multi read hosts -->
22 <readHost host="hostS2" url="192.168.8. 151:3310" user="blt" password="blt" />
23                 </writeHost>

7、测试

[root@mycat ~]# /usr/local/mycat/bin/mycat start

[root@mycat ~]# netstat -lnput | grep 8066
[root@client ~]# cd mysql-5.7.44-linux-glibc2.12-x86_64/
[root@client mysql-5.7.44-linux-glibc2.12-x86_64]# cd bin/
[root@client bin]# ./mysql -h192.168.8.152 -P8066 -ublt -pblt

mysql> show databases;
+--------------------+
| Database           |
+--------------------+              |
| test               |
+--------------------+
1 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 -ADatabase changed
mysql> select * from user;
+----+----------+----------+
| id | username | password |
+----+----------+----------+
|  1 | aaa      | aaa      |
+----+----------+----------+
1 row in set (0.00 sec)mysql> show variables like "server_id";
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 10    |
+---------------+-------+
1 row in set (0.02 sec)