nginx的4层负载均衡

nginx可以实现4层负载均衡。

软件四层负载均衡&＃xff1a;
通过报文(数据包)中的目标地址和端口&＃xff0c;加上分发机上的调度算法&＃xff0c;决定最终选择哪个RIP。
LVS

软件七层负载均衡&＃xff1a;
通过看客户端请求的具体内容(文字、图片、视频&＃xff1b;网站交互)进行最终选择。

网络中常见的 SYN Flood 攻击。DOS。DDOS

nginx的4层负载均衡有2个条件&＃xff1a;

1、版本在1.10以上

2、配置选项要有stream

[root&＃64;nginx-4c ~]# /usr/local/nginx/sbin/nginx -V
nginx version: nginx/1.17.6
built by gcc 4.8.5 20150623 (Red Hat 4.8.5-39) (GCC)
built with OpenSSL 1.0.2k-fips 26 Jan 2017
TLS SNI support enabled
configure arguments: --prefix&＃61;/usr/local/nginx --user&＃61;www --group&＃61;www --with-http_stub_status_module --with-http_v2_module --with-http_ssl_module --with-http_sub_module --with-http_gzip_static_module --with-http_realip_module --with-stream--with-stream <--要这个选项


配置&＃xff1a;

pid logs/nginx.pid;
events {worker_connections 1024;use epoll;
}
》》》》》》》》》》》》》》》》》》》》》》》》
stream {upstream p_ssh { hash $remote_addr consistent;server 172.16.12.71:22; server 172.16.12.72:22;}server {listen 24678;proxy_connect_timeout 3s; proxy_timeout 10s;proxy_pass p_ssh;}
}
》》》》》》》》》》》》》》》》》》》》》》》》


然后重启服务&＃xff1a;
查端口&＃xff0c;有24678那个新添加的端口

[root&＃64;nginx-4c nginx]# netstat -antlup | grep nginx
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 882/nginx: master p
tcp 0 0 0.0.0.0:24678 0.0.0.0:* LISTEN 882/nginx: master p

访问测试&＃xff1a;

[root&＃64;localhost mnt]# ssh -p 24678 root&＃64;172.16.12.82root&＃64;172.16.12.82&＃39;s password:
Last login: Sat Jan 4 00:59:11 2020 from 172.16.12.1
[root&＃64;chunk1 ~]# Connection to 172.16.12.82 closed by remote host.
Connection to 172.16.12.82 closed.


能够登录转发。

mysql

172.16.12.71

装个mysql

[root&＃64;chunk1 ~]# yum install mariadb-server -y [root&＃64;chunk1 ~]# systemctl restart mariadb
[root&＃64;chunk1 ~]# mysqlMariaDB [(none)]> grant select on *.* to &＃39;read&＃39;&＃64;&＃39;172.16.%&＃39; identified by &＃39;12345&＃39;;
MariaDB [(none)]> flush privileges;


172.16.12.72

MariaDB [(none)]> grant all on *.* to &＃39;write&＃39;&＃64;&＃39;172.16.%&＃39; identified by &＃39;12345&＃39;;
MariaDB [(none)]> flush privileges;


stream {upstream mysql_read {hash $remote_addr consistent;server 172.16.12.71:3306 weight&＃61;10 max_fails&＃61;3 fail_timeout&＃61;2s;} upstream mysql_write {hash $remote_addr consistent;server 172.16.12.72:3306 weight&＃61;10 max_fails&＃61;3 fail_timeout&＃61;2s;} server {listen 3306;proxy_connect_timeout 3s;proxy_timeout 10s;proxy_pass mysql_read;}server {listen 3307;proxy_connect_timeout 3s;proxy_timeout 10s;proxy_pass mysql_write;}
}


重启查端口&＃xff1a;
看到3306、3307&＃xff0c;这两个是nginx启动的端口。

[root&＃64;nginx-4c nginx]# netstat -antlup | grep nginx
tcp 0 0 0.0.0.0:3307 0.0.0.0:* LISTEN 882/nginx: master p
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 882/nginx: master p
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 882/nginx: master p


访问测试&＃xff1a;

[root&＃64;client ~]# yum install -y mariadb


[root&＃64;client ~]# mysql -h 172.16.12.82 -P 3306 -u read -p12345
Welcome to the MariaDB monitor. Commands end with ; or \g.


[root&＃64;client ~]# mysql -h 172.16.12.82 -P 3307 -u write -p12345
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 3


都能访问转发。ok了。