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Nginx实现负载均衡

程序员文章站 2024-01-31 23:19:16
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1.Nginx简介

Nginx是一款高性能的http 服务器/反向代理服务器及电子邮件（IMAP/POP3）代理服务器。由俄罗斯的程序设计师Igor Sysoev所开发，官方测试nginx能够支支撑5万并发链接，并且cpu、内存等资源消耗却非常低，运行非常稳定。

2.Nginx应用场景

1、http服务器。Nginx是一个http服务可以独立提供http服务。可以做网页静态服务器。
2、虚拟主机。可以实现在一台服务器虚拟出多个网站。例如个人网站使用的虚拟主机。
3、反向代理，负载均衡。当网站的访问量达到一定程度后，单台服务器不能满足用户的请求时，需要用多台服务器集群可以使用nginx做反向代理。并且多台服务器可以平均分担负载，不会因为某台服务器负载高宕机而某台服务器闲置的情况。

[root@server2 ~]# ls
anaconda-ks.cfg  install.log  install.log.syslog  nginx-1.14.0.tar.gz
[root@server2 ~]# tar zxf nginx-1.14.0.tar.gz 
[root@server2 ~]# ls
anaconda-ks.cfg  install.log.syslog  nginx-1.14.0.tar.gz
install.log      nginx-1.14.0
[root@server2 ~]# cd nginx-1.14.0
[root@server2 nginx-1.14.0]# ls
auto     CHANGES.ru  configure  html     man     src
CHANGES  conf        contrib    LICENSE  README
[root@server2 ~]# cd nginx-1.14.0/src/core/
[root@server2 core]# ls
nginx.c           ngx_inet.h             ngx_radix_tree.h
nginx.h           ngx_list.c             ngx_rbtree.c


.........略
[root@server2 core]# vim nginx.h
[root@server2 core]# cd ..
[root@server2 src]# cd ..
[root@server2 nginx-1.14.0]# ls
auto     CHANGES.ru  configure  html     man     src
CHANGES  conf        contrib    LICENSE  README
[root@server2 nginx-1.14.0]# cd auto/
[root@server2 auto]# ls
cc          feature       headers  install  module   options  stubs    types
define      have          include  lib      modules  os       summary  unix
endianness  have_headers  init     make     nohave   sources  threads
[root@server2 auto]# cd cc/
[root@server2 cc]# ls
acc  bcc  ccc  clang  conf  gcc  icc  msvc  name  owc  sunc
[root@server2 cc]# vim gcc 
注释掉debug如下
# debug
#CFLAGS="$CFLAGS -g"

[root@server2 cc]# cd ..
[root@server2 auto]# cd ..
[root@server2 nginx-1.14.0]# ls
auto     CHANGES.ru  configure  html     man     src
CHANGES  conf        contrib    LICENSE  README
[root@server2 nginx-1.14.0]# ./conf
conf/      configure  
[root@server2 nginx-1.14.0]# ./configure --help

 略

[root@server2 nginx-1.14.0]# ./configure --prefix=/usr/local/nginx --with-http_ssl_module --with-http_stub_status_module --with-threads --with-file-aio
checking for OS
 + Linux 2.6.32-431.el6.x86_64 x86_64
checking for C compiler ... not found

./configure: error: C compiler cc is not found
解决依赖性，这里一次性解决，值得注意的是，一般来说编译过程中报的依赖性错误，包名后需要加-devel    
[root@server2 nginx-1.14.0]# yum install -y gcc pcre-devel openssl-devel


Complete!
[root@server2 nginx-1.14.0]# ./configure --prefix=/usr/local/nginx --with-http_ssl_module --with-http_stub_status_module --with-threads --with-file-aio
略
[root@server2 nginx-1.14.0]# make
[root@server2 nginx-1.14.0]# make install
[root@server2 nginx-1.14.0]# cd /usr/local/nginx/
[root@server2 nginx]# ls
conf  html  logs  sbin
[root@server2 nginx]# du -sh
980K    .
[root@server2 nginx]# cd sbin/
[root@server2 sbin]# pwd
/usr/local/nginx/sbin
[root@server2 sbin]# ls
nginx
创建可执行软连接
[root@server2 sbin]# ln -s /usr/local/nginx/sbin/nginx /sbin/
检查语法
[root@server2 sbin]# nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful
打开nginx
[root@server2 sbin]# nainx
-bash: nainx: command not found
[root@server2 sbin]# nginx
关闭nginx
[root@server2 sbin]# nginx -s stop
[root@server2 sbin]# nginx
重启nginx
[root@server2 sbin]# nginx -s reload
这是nginx的发布目录，网络访问页面如下

[root@server2 sbin]# curl localhost
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

Nginx实现负载均衡

[root@server2 sbin]# cd /usr/local/nginx/
[root@server2 nginx]# ls
client_body_temp  fastcgi_temp  logs        sbin       uwsgi_temp
conf              html          proxy_temp  scgi_temp
[root@server2 nginx]# cd html/
[root@server2 html]# pwd
/usr/local/nginx/html
[root@server2 html]# ls
50x.html  index.html
[root@server2 html]# vim test.html
[root@server2 html]# cat test.html 
<h1>test test.html</h1>

Nginx实现负载均衡

[aaa@qq.com ~]# cd /usr/local/nginx/
[aaa@qq.com nginx]# ls
client_body_temp  fastcgi_temp  logs        sbin       uwsgi_temp
conf              html          proxy_temp  scgi_temp
[aaa@qq.com nginx]# cd conf/
[aaa@qq.com conf]# ls
fastcgi.conf            koi-win             scgi_params
fastcgi.conf.default    mime.types          scgi_params.default
fastcgi_params          mime.types.default  uwsgi_params
fastcgi_params.default  nginx.conf          uwsgi_params.default
koi-utf                 nginx.conf.default  win-utf



``查看本机cpu
[aaa@qq.com conf]# lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                1
On-line CPU(s) list:   0
Thread(s) per core:    1
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 42
Stepping:              1
CPU MHz:               2491.904
BogoMIPS:              4983.80
Hypervisor vendor:     KVM
Virtualization type:   full
L1d cache:             32K
L1i cache:             32K
L2 cache:              4096K
NUMA node0 CPU(s):     0
[aaa@qq.com conf]# vim nginx.conf
[aaa@qq.com conf]# sysctl -a|grep file
fs.file-nr = 448098863
fs.file-max = 98863

[aaa@qq.com conf]# vim /etc/security/limits.conf 
[aaa@qq.com conf]# vim nginx.conf
[aaa@qq.com conf]# useradd -M -d /usr/local/nginx/ nginx     添加用户
[aaa@qq.com conf]# id nginx
uid=500(nginx) gid=500(nginx) groups=500(nginx)
[aaa@qq.com conf]# nginx -s reload
[aaa@qq.com conf]# ps ax 

[aaa@qq.com conf]# vim nginx.conf     主配置文件


user  nginx;            ##用户
#cpu worker          
worker_processes  1;




events {
    worker_connections  65535;          进程文件数
}

轮叫配置
http {  
    upstream westos {
    #ip_hash;
    server 172.25.53.3:80 weight=2;
    server 172.25.53.4:80;
    server 127.0.0.1:80 backup;
    }
    include       mime.types;
    default_type  application/octet-stream;



    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;
端口
    server {
        listen       80;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
            root   html;
            index  index.html index.htm;
        }

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }


    }


    server {
        listen 80;
        server_name www.westos.org;

        location / {
        proxy_pass http://westos;
        }
    }
}
检查语法
[aaa@qq.com conf]# nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful
[aaa@qq.com conf]# nginx -s reload


----------


[aaa@qq.com 777]# for i in {1..10}; do curl www.westos.org; done
www.westos.org - server4 
www.westos.org - server3
www.westos.org - server4 
www.westos.org - server3
www.westos.org - server4 
www.westos.org - server3
www.westos.org - server4 
www.westos.org - server3
www.westos.org - server4 
www.westos.org - server3


----------


Done掉server3后
[aaa@qq.com 777]# for i in {1..10}; do curl www.westos.org; done
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 


----------


都done掉后
[aaa@qq.com 777]# curl www.westos.org
<html>
<head><title>502 Bad Gateway</title></head>
<body bgcolor="white">
<center><h1>502 Bad Gateway</h1></center>
<hr><center>nginx/</center>
</body>
</html>


----------


打开server4后
[aaa@qq.com 777]# for i in {1..10}; do curl www.westos.org; done
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 
www.westos.org - server4 


----------


添加权重后
[aaa@qq.com 777]# for i in {1..10}; do curl www.westos.org; done
www.westos.org - server3
www.westos.org - server4 
www.westos.org - server3
www.westos.org - server3
www.westos.org - server4 
www.westos.org - server3
www.westos.org - server3
www.westos.org - server4 
www.westos.org - server3
www.westos.org - server3


----------


添加
server 127.0.0.1:80 backup; 后，nginx发布自己的
[aaa@qq.com 777]# curl www.westos.org
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>


----------

添加ip_hash;
ip_hash

             每个请求按照客户端IP的hash结果分配，新的请求到达时，先将客户端IP通过哈希算法哈希出一个值，在随后的的客户端请求中，客户IP的哈希值只要相同，就会被分配至同一台服务器，该调度算法可以解决动态网页的session共享问题，但是会导致请求分配不均

  （在upstream里配置,如果是ip_hash，不能有weight和bakcup）

网页粘滞


Server3和server4只需安装httpd并打开，发布目录写东西即可


















为查看    sticky;效果，我们在另一个路径下安装nginx，停掉原来的，互不影响，只是为了执行时分清，用根目录方式执行

[aaa@qq.com ~]# ls
anaconda-ks.cfg install.log.syslog nginx-1.14.0.tar.gz
install.log nginx-1.14.0
[aaa@qq.com ~]# ls
anaconda-ks.cfg nginx-1.10.1.tar.gz nginx-sticky-module-ng.tar.gz
install.log nginx-1.14.0
install.log.syslog nginx-1.14.0.tar.gz
[aaa@qq.com ~]# nginx -s stop
[aaa@qq.com ~]# tar zxf nginx-1.10.1.tar.gz
[aaa@qq.com ~]# ls
anaconda-ks.cfg nginx-1.10.1 nginx-1.14.0.tar.gz
install.log nginx-1.10.1.tar.gz nginx-sticky-module-ng.tar.gz
install.log.syslog nginx-1.14.0
[aaa@qq.com ~]# cd nginx-1.10.1
nginx-1.10.1/ nginx-1.10.1.tar.gz
[aaa@qq.com ~]# cd nginx-1.10.1
[aaa@qq.com nginx-1.10.1]# ls
auto CHANGES.ru configure html man src
CHANGES conf contrib LICENSE README
[aaa@qq.com nginx-1.10.1]# cd
[aaa@qq.com ~]# ls
anaconda-ks.cfg nginx-1.10.1 nginx-1.14.0.tar.gz
install.log nginx-1.10.1.tar.gz nginx-sticky-module-ng.tar.gz
install.log.syslog nginx-1.14.0
[aaa@qq.com ~]# tar zxf nginx-sticky-module-ng.tar.gz
[aaa@qq.com ~]# ls
anaconda-ks.cfg nginx-1.10.1 nginx-1.14.0.tar.gz
install.log nginx-1.10.1.tar.gz nginx-sticky-module-ng
install.log.syslog nginx-1.14.0 nginx-sticky-module-ng.tar.gz
[aaa@qq.com ~]# cd nginx-1.10.1
[aaa@qq.com nginx-1.10.1]# ./configure –prefix=/opt/nginx –with-http_ssl_module –with-http_stub_status_module –with-threads –with-file-aio –add-module=/root/nginx-sticky-module-ng
[aaa@qq.com nginx-1.10.1]# make
[aaa@qq.com nginx-1.10.1]# make install
[aaa@qq.com nginx-1.10.1]# cd /opt/nginx/
[aaa@qq.com nginx]# ls
conf html logs sbin
[aaa@qq.com nginx]# cd conf/
[aaa@qq.com conf]# ls
fastcgi.conf koi-win scgi_params
fastcgi.conf.default mime.types scgi_params.default
fastcgi_params mime.types.default uwsgi_params
fastcgi_params.default nginx.conf uwsgi_params.default
koi-utf nginx.conf.default win-utf
[aaa@qq.com conf]# cp /usr/local/nginx/conf/nginx.conf .
cp: overwrite `./nginx.conf’? y
[aaa@qq.com conf]# vim nginx.conf
[aaa@qq.com conf]# ll /sbin/nginx
lrwxrwxrwx 1 root root 27 Jul 31 15:40 /sbin/nginx -> /usr/local/nginx/sbin/nginx

[aaa@qq.com conf]# /opt/nginx/sbin/nginx -t
nginx: the configuration file /opt/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /opt/nginx/conf/nginx.conf test is successful
[aaa@qq.com conf]# /opt/nginx/sbin/nginx
[aaa@qq.com conf]# /opt/nginx/sbin/nginx -s reload




http {
        upstream westos {
        #ip_hash;
        sticky;
        server 172.25.53.3:80 weight=2;
        server 172.25.53.4:80;
        #server 127.0.0.1:80 backup;
        }

效果为网页访问www.westos.org时，稳定在同一页面，但curl时则不是
![这里写图片描述](https://img-blog.csdn.net/20180801144533829?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2F3b3lhb2M=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70)

[aaa@qq.com ~]# for i in {1..10}; do curl www.westos.org; done
www.westos.org - server4
www.westos.org - server3
www.westos.org - server3
www.westos.org - server4
www.westos.org - server3
www.westos.org - server3
www.westos.org - server4
www.westos.org - server3
www.westos.org - server3
www.westos.org - server4
“`

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