Nginx-负载均衡实现

Nginx 负载均衡操作案例

Nginx负载均衡的组件模块

upstream模块介绍->点我<

环境准备

 

1)四台服务器都需操作如下步骤:

# systemctl stop firewalld        //关闭防火墙
# sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/sysconfig/selinux        //关闭selinux,重启生效
# setenforce 0        //关闭selinux,临时生效
# ntpdate 0.centos.pool.ntp.org        //时间同步

2)LB节点源码安装nginx:

# yum install openssl openssl-devel pcre pcre-devel gcc gcc-c++ make autoconf automake -y        //安装依赖工具包

//编写安装脚本 # cat >installNginx.sh<<EOF     mkdir /home/tools cd /home/tools wget -q http://nginx.org/download/nginx-1.12.2.tar.gz ls -l nginx-1.12.2.tar.gz useradd nginx -s /sbin/nologin -M tar xf nginx-1.12.2.tar.gz cd nginx-1.12.2 ./configure --user=nginx --group=nginx --prefix=/application/nginx-1.12.2 --with-http_stub_status_module --with-http_ssl_module make make install ln -s /application/nginx-1.12.2/ /application/nginx EOF
# bash installNginx.
sh //执行安装脚本

说明:上面源码安装的nginx,配置文件路径:/application/nginx/conf/nginx.conf    二进制启动命令路径:/application/nginx/sbin/nginx

3)web节点yum安装nginx及准备测试文件:

# yum install nginx -y        //安装nginx
# mkdir /application/nginx/html/{www,bbs,blog} -p        //创建web站点目录
# for dir in www bbs blog; do echo "`hostname` $dir" >/application/nginx/html/$dir/index.html;done        //创建站点目录测试文件
# vim /etc/nginx/nginx.conf        //编辑配置文件
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

http {
    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;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;
    include /etc/nginx/conf.d/*.conf;

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

        location / {
        root /application/nginx/html/www;
        }
        access_log      /var/log/nginx/access_www.log main;
    }

    server {
        listen       80;
        server_name  bbs.etiantian.org;

        location / {
        root /application/nginx/html/bbs;
        }
        access_log      /var/log/nginx/access_bbs.log main;
    }
    server {
        listen       80;
        server_name  blog.etiantian.org;

        location / {
        root /application/nginx/html/blog;
        }
        access_log      /var/log/nginx/access_blog.log main;
    }
}

# systemctl start nginx        //启动nginx
# systemctl enable nginx        //加入开机自启动

4)web站点配置hosts解析及测试nginx是否能够正常访问

//web1站点编辑后的/etc/hosts文件
[root@centos7-3 ~]# tail -3 /etc/hosts
192.168.3.103   www.etiantian.org
192.168.3.103   bbs.etiantian.org
192.168.3.103   blog.etiantian.org

//web2站点编辑后的/etc/hosts文件
[root@centos7-4 ~]# tail -3 /etc/hosts
192.168.3.104   www.etiantian.org
192.168.3.104   bbs.etiantian.org
192.168.3.104   blog.etiantian.org

//web1站点测试
[root@centos7-3 ~]# curl www.etiantian.org
centos7-3 www
[root@centos7-3 ~]# curl bbs.etiantian.org
centos7-3 bbs
[root@centos7-3 ~]# curl blog.etiantian.org
centos7-3 blog

//web2站点测试
[root@centos7-4 ~]# curl www.etiantian.org
centos7-4 www
[root@centos7-4 ~]# curl bbs.etiantian.org
centos7-4 bbs
[root@centos7-4 ~]# curl blog.etiantian.org
centos7-4 blog

案例

完成上面的lb节点的软件安装及web节点的测试文件准备后,下面开始配置案例,说明,先配置单节点的lb,也就是先只在(centos7-1)lb1 上面进行配置。

案例一:最基本的负载均衡

编辑lb1(192.168.3.101)配置文件,编辑之前记得将默认配置文件进行备份

# cp /application/nginx/conf/nginx.conf /application/nginx/conf/nginx.conf.default        //备份配置文件
# sed -i '/^[ ]*$/d' /application/nginx/conf/nginx.conf        //去掉配置文件中的注释及空行
# vim /application/nginx/conf/nginx.conf        //编辑配置文件
worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;

    upstream myapp1 {
        #<== upstream 是关键字必须要有,后面的myapp1为一个Upstream集群组的名字,可以自定义,调用时就用这个名字。
        server 192.168.3.103 weight=1;
        #<==server 关键字是固定的,后面可以接域名或IP,如果不指定端口,默认是80端口。weight 代表权重,数值越大被分配到请求越多,默认值为1,所以此处可写可不写。结尾有分号,别忘了;
        server 192.168.3.104 weight=1;
     }
    server {
        listen       80;
        server_name  localhost;
    location / {
            proxy_pass http://myapp1;
        }
    }
}

# /application/nginx/sbin/nginx -t        //检查语法是否错误
# /application/nginx/sbin/nginx -s reload        //重新加载配置文件

我们用lb2机器来测试(用任何一台都可以),测试结果可以看出,会轮循调度到后端web节点上

[root@centos7-2 ~]# curl 192.168.3.101
centos7-3 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-4 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-3 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-4 www

案例二:基于权重(wrr)

修改配置文件 upstream 段为以下内容

upstream myapp1 {
    server 192.168.3.103 weight=1;
    server 192.168.3.104 weight=2;
}

同样使用lb2机器来进行测试,可以发现调度后端节点编程了1:2,调度到web2节点上面总是会多一次。

[root@centos7-2 ~]# curl 192.168.3.101
centos7-3 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-4 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-4 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-3 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-4 www
[root@centos7-2 ~]# curl 192.168.3.101
centos7-4 www

案例三:较完整的 upstream 配置案例

修改配置文件 upstream 段为以下内容

upstream myapp1 {
    server 192.168.3.103 weight=1 max_fails=3 fail_timeout=20s;
    server 192.168.3.104 weight=1 max_fails=3 fail_timeout=20s;
}
//max_fails 尝试连接后端主机失败的次数; fail_timeout 在max_fails定义的失败次数后,距离下次检查的间隔时间。

同样使用lb2机器来进行测试,在测试过程中,关闭其中一个web节点,会发现只是调度到另外一个节点上面,然后再重启关闭的节点,观察测试输出内容,会发现尝试的时间。

[root@centos7-2 ~]# for n in {1..100}; do curl 192.168.3.101 ; date +%T; sleep 1; done

案例四:基于域名的负载

修改配置文件为以下内容

worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;

    upstream myapp1 {
        server 192.168.3.103 weight=1 max_fails=3 fail_timeout=20s;
        server 192.168.3.104 weight=1 max_fails=3 fail_timeout=20s;
     }

    server {
        listen       80;
        server_name  www.etiantian.org;
    location / {
            proxy_pass http://myapp1;
            proxy_set_header Host $host;
        }
    }

    server {
        listen       80;
        server_name  bbs.etiantian.org;
    location / {
            proxy_pass http://myapp1;
            proxy_set_header Host $host;
        }
    }

    server {
        listen       80;
        server_name  blog.etiantian.org;
    location / {
            proxy_pass http://myapp1;
            proxy_set_header Host $host;
        }
    }
}

编辑/etc/hosts文件,进行域名解析,此处为了方便,直接在lb1节点上面编辑并测试(如果需要在别的节点进行测试,那么进行域名解析即可)

# vim /etc/hosts
192.168.3.101   www.etiantian.org bbs.etiantian.org blog.etiantian.org

测试发现基于域名ok,因为上面配置的权重都为1,所以不论我们访问哪一个域名,都会轮循去调度后端web节点。

[root@centos7-1 ~]# curl www.etiantian.org
centos7-4 www
[root@centos7-1 ~]# curl www.etiantian.org
centos7-3 www
[root@centos7-1 ~]# curl bbs.etiantian.org
centos7-4 bbs
[root@centos7-1 ~]# curl bbs.etiantian.org
centos7-3 bbs
[root@centos7-1 ~]# curl blog.etiantian.org
centos7-4 blog
[root@centos7-1 ~]# curl blog.etiantian.org
centos7-3 blog

案例五:记录客户端真实IP

先到web节点上面查看访问日志

[root@centos7-3 ~]# tailf /var/log/nginx/access_www.log 
192.168.3.101 - - [08/Apr/2019:00:18:14 +0800] "GET / HTTP/1.0" 200 14 "-" "curl/7.29.0" "-"
192.168.3.101 - - [08/Apr/2019:00:18:16 +0800] "GET / HTTP/1.0" 200 14 "-" "curl/7.29.0" “-"

通过观察日志发现,记录的都负载均衡器节点的IP,实际生产环境中都是记录真实客户端IP。

进行修改配置文件(lb节点)将location 段加上 proxy_set_header X-Forwarded-For $remote_addr;

location / {
        proxy_pass http://myapp1;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $remote_addr;
    }

使用lb2节点进行测试(我们将lb2当做一个客户端访问),然后我们再去查看日志就可以发现,记录了客户端的真实IP地址。

[root@centos7-3 ~]# tailf /var/log/nginx/access_www.log 
192.168.3.101 - - [08/Apr/2019:00:36:06 +0800] "GET / HTTP/1.0" 200 14 "-" "curl/7.29.0" "192.168.3.102"
192.168.3.101 - - [08/Apr/2019:00:36:07 +0800] "GET / HTTP/1.0" 200 14 "-" "curl/7.29.0" "192.168.3.102"

案例六:根据不同的URI 调度到不同的服务器

常见架构图

梳理:1、当用户请求 www.etiantian.org/upload/xx 地址时,实现由upload上传服务器池处理请求;2、当用户请求 www.etiantian.org/static/xx 地址时,实现由静态服务器池处理请求;3、除此之外,对于其它访问请求,全部由默认的动态服务器池处理请求。如下图:

在wab服务器上面准备测试文件

//准备测试文件web1的80 upload
[root@centos7-3 ~]# mkdir /application/nginx/html/www/upload
[root@centos7-3 ~]# echo "upload web01 192.168.3.103 " > /application/nginx/html/www/upload/index.html
//准备测试文件web2的80 static
[root@centos7-4 ~]# mkdir /application/nginx/html/www/static
[root@centos7-4 ~]# echo "static web02 192.168.3.104 " > /application/nginx/html/www/static/index.html 
//准备测试文件web2的8080 default
[root@centos7-4 ~]# mkdir /application/nginx/www_8080
[root@centos7-4 ~]# vim /etc/nginx/conf.d/www_8080.conf
server {
    listen          80;
    server_name     localhost;
    access_log      /var/log/nginx/access.log main;
    location / {
        root /application/nginx/www_8080;
        index index.html index.htm;
    }
}
[root@centos7-4 ~]# echo "default web02 192.168.3.104 " > /application/nginx/www_8080/index.html

//在lb1服务器测试后端web服务器是否能够正常访问
[root@centos7-1 ~]#curl 192.168.3.103/upload/index.html
upload web01 192.168.3.103 
[root@centos7-1 ~]# curl 192.168.3.104/static/index.html
static web02 192.168.3.104 
[root@centos7-1 ~]# curl 192.168.3.104:8080/index.html
default web02 192.168.3.104

配置LB,修改lb1配置文件进行配置

sendfile        on;
keepalive_timeout  65;

upstream upload_pools {
    server 192.168.3.103:80;
 }
upstream static_pools {
    server 192.168.3.104:80;
 }
upstream default_pools {
    server 192.168.3.104:8080;
 }

server {
    listen       80;
    server_name  www.etiantian.org;
location / {
        proxy_pass http://default_pools;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $remote_addr;
    }
location /upload {
        proxy_pass http://upload_pools;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $remote_addr;
    }
location /static {
        proxy_pass http://static_pools;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $remote_addr;
    }
}

在lb2(模拟客户端)节点上面进行测试,结果可以看到根据不同的url调度到不同的服务器上面了。

[root@centos7-2 ~]# curl 192.168.3.101
default web02 192.168.3.104 
[root@centos7-2 ~]# curl 192.168.3.101/upload/index.html
upload web01 192.168.3.103 
[root@centos7-2 ~]# curl 192.168.3.101/static/index.html
static web02 192.168.3.104

  

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转载自www.cnblogs.com/yanjieli/p/10670773.html