如何用nginx搭建MySQL负载均衡？域名解析与安装部署详解

[root@c-nginx-com nginx]# vim /etc/hosts

10.11.59.38 c.nginx.com
10.11.59.147 a.nginx.com
10.11.59.37 b.nginx.com

[root@c-nginx-com nginx]# ping  -c1 a.nginx.com

PING a.nginx.com (10.11.59.147) 56(84) bytes of data.
64 bytes from a.nginx.com (10.11.59.147): icmp_seq=1 ttl=64 time=0.591 ms

--- a.nginx.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.591/0.591/0.591/0.000 ms

#!/bin/bash
# by xiaohei
# time 2020-4-28

echo "此脚本用于yum 安装mysql"
if [[ $UID -ne 0 ]];then
	echo "使用root 执行此脚本"
	exit 1
fi
if [[ $# != 1 ]];then
	echo "Usage script (5.5|5.6|5.7|8.0)"
	exit 123
fi
echo "清理环境"
systemctl stop mysqld mariadb &>/dev/null
yum erase -y `rpm -qa |grep mariadb` 2>/dev/null
yum erase -y `rpm -qa |grep mysql`  2>/dev/null
rm -rvf /etc/my.cnf /var/lib/mysql /var/log/mysql*
userdel -rf mysql &>/dev/null
ping -c1 -w1 www.baidu.com &>/dev/null
if [[ $? -eq 0 ]];then
	yum install -y wget yum-utils &>/dev/null
	if [[ $? -ne 0 ]];then
		echo "yum 配置错误"
		exit 110
	fi
	yum install -y https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm
	yum clean all
	yum makecache fast
else
	echo "网络错误"
	exit 22
fi

case $1 in
5.5)
    yum-config-manager  --disable mysql80-community
    yum-config-manager  --enable mysql55-community
;;
5.6)
	yum-config-manager  --disable mysql80-community
	yum-config-manager  --enable mysql56-community
;;
5.7)
	yum-config-manager  --disable mysql80-community
	yum-config-manager  --enable mysql57-community
;;
8.0)
	:
;;
*)
	yum repolist all |grep mysql
	echo "其他版本可自行选择下载并配置"
	exit 13
;;
esac
sleep 2
yum -y install mysql-community-server
systemctl start mysqld
echo "启动成功，初始密码如下(mysql5.7前版本没有初始密码)"
grep -o 'root@localhost.*' /var/log/mysqld.log
echo "安装完成"

[root@b-nginx-com ~]# mysqladmin -u root -p"脚本显示的密码" password 'QianFeng@123'

mysql> create database db1;
mysql> use db1
mysql> create table t1(id int,name char(50));
mysql> show tables;
+---------------+
| Tables_in_db1 |
+---------------+
| t1            |
+---------------+
1 row in set (0.00 sec)

mysql> into t1(id,name) values(1,'b.mysql.com');    #在10.11.59.37上面做的，为了效果需要把name数据换成二个不一样的，其他一样
mysql> select * from t1;
+------+-------------+
| id   | name        |
+------+-------------+
|    1 | b.mysql.com |
+------+-------------+
1 row in set (0.00 sec)

mysql>grant all on db1.* to test@'%' identified by '密码';

[root@c-nginx-com nginx]# nginx -v
nginx version: nginx/1.18.0

[root@c-nginx-com ~]# vim /etc/yum.repos.d/nginx.repo

[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key

[nginx-mainline]
name=nginx mainline repo
baseurl=http://nginx.org/packages/mainline/centos/$releasever/$basearch/
gpgcheck=1
enabled=0
gpgkey=https://nginx.org/keys/nginx_signing.key

[root@c-nginx-com ~]# yum -y install nginx

[root@c-nginx-com ~]# vim /etc/nginx/nginx.conf

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}
#-----------------往下--------------------
#四层负载，四层的负载不在http模块里面，他是和http模块同级别的
stream {        
                upstream mysql {
                server 10.11.59.147:3306;  #后端数据库的ip和端口，如果进行了域名解析，直接写域名就好
                server 10.11.59.37:3306;   #同上
        }
        server {
            listen 3306;   #如果监听3306，远程登录的时候不用加-p参数
            proxy_connect_timeout 10s;
            proxy_timeout 30s;
            proxy_pass mysql;
        }
}
#------------------往上--------------------
http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  0;
    #keepalive_timeout  65;

    #gzip  on;

    include /etc/nginx/conf.d/*.conf;
}

[root@c-nginx-com ~]# systemctl start nginx
[root@c-nginx-com ~]# systemctl enable nginx

[root@c-nginx-com ~]# mysql -u test -p'QianFeng@123' -h '10.11.59.38' -e "select * from db1.t1;"
+------+-------------+
| id   | name        |
+------+-------------+
|    1 | a.mysql.com |
+------+-------------+
[root@c-nginx-com ~]# mysql -u test -p'QianFeng@123' -h '10.11.59.38' -e "select * from db1.t1;"
+------+-------------+
| id   | name        |
+------+-------------+
|    1 | b.mysql.com |
+------+-------------+
[root@c-nginx-com ~]# mysql -u test -p'QianFeng@123' -h '10.11.59.38' -e "select * from db1.t1;"
+------+-------------+
| id   | name        |
+------+-------------+
|    1 | a.mysql.com |
+------+-------------+
[root@c-nginx-com ~]# mysql -u test -p'QianFeng@123' -h '10.11.59.38' -e "select * from db1.t1;"
+------+-------------+
| id   | name        |
+------+-------------+
|    1 | b.mysql.com |
+------+-------------+