负载均衡之七层负载均衡nginx实现动静分离

╰半橙微兮° 2022-05-22 06:43 255阅读 0赞

# 一，集群的分类：    #

**高可用集群 HA high availability**  
 避免单节点故障  
软件：keepalived   
  
**负载均衡集群 LB load balance**  
提高负载，提高并发量  
软件：nginx反向代理 lvs  
硬件负载均衡器 F5(BigIP)和redware  
  
HPC高性能运算集群  
**分布式存储集群**  
极大的提升存储容量，提供数据高可用，保证数据安全  
软件：ceph  
  
  
Nginx proxy 是 Nginx 的王牌功能,利用 proxy 基本可以实现一个完整的 7 层负载均。  
1. 功能强大,性能卓越,运行稳定。  
2. 配置简单灵活。  
3. 能够自动剔除工作不正常的后端服务器。  
4. 上传文件使用异步模式。  
5. 支持多种分配策略,可以分配权重,分配方式灵活。

# 二，实验的过程（七层负载均衡） #

## 1.实验环境：三台机器 ##

192.168.78.131 \#安装apache，php  
192.168.78.136 \#安装apache，php  
192.168.78.143 \#需要源码安装的nginx ，作为代理服务器负责负载均衡，还需要在安装之前创建用户nginx -s /sbin/nologin 指定它不能登陆

## 2.开启被代理机器的服务及配置： ##

对机器192.168.78.131：  
systemctl start httpd  
\# cd /var/www/html  
\# rm -rf index.html \#删除它默认的主页  
\#vim index.html  
192.168.78.131 \#保存退出  
准备一张图片名字叫做pic.jpg放在/var/www/html里面  
\#vim test.php  
192.168.78.131-php  
<?php  
phpinfo();  
?>  
此时在/var/www/html里面就有index.html,test.php,pic.jpg三个文件  
\#systemctl restart httpd \#重启服务  
对机器192.168.78.136：  
systemctl start httpd  
\# cd /var/www/html  
\# rm -rf index.html \#删除它默认的主页  
\#vim index.html  
192.168.78.136 \#保存退出  
准备一张图片名字叫做pic.jpg放在/var/www/html里面 和上面的图片不一样，只是名字一样  
\#vim test.php  
192.168.78.136-php  
<?php  
phpinfo();  
?>  
此时在/var/www/html里面就有index.html,test.php,pic.jpg三个文件  
\#systemctl restart httpd \#重启服务

## 3.配置nginx服务器192.168.78.143 ##

假如我的nginx安装在/usr/local/目录里面  
  
配置如下：  
\#vim /usr/local/nginx/conf/nginx.conf  
\#user nobody;  
user nginx; **\#把用户改为nginx**  
  
location / \{  **\# location是放在server\{\}里面的**  
root html;  
index index.html index.htm;  
  
if ($request\_uri ~\* \\.html$)\{  
proxy\_pass http://htmlservers;  
\}  
  
if ($request\_uri ~\* \\.php$)\{  
proxy\_pass http://phpservers;  
\}  
  
proxy\_pass http://picservers;  
\}  
  
  
upstream htmlservers \{ **\#这是负载均衡的服务器，注意这一块要放在http\{\}里面和server\{\}的外面**  
server 192.168.78.131:80;  
server 192.168.78.136:80;  
\}  
upstream phpservers \{  
server 192.168.78.131:80;  
server 192.168.78.136:80;  
\}  
upstream picservers \{  
server 192.168.78.131:80;  
server 192.168.78.136:80;  
\}  
  
\#/usr/local/nginx/sbin/nginx -s reload **\#重新加载配置文件并启动**

## 4.测试： ##

在其他任意机器上或者192.168.78.143机器上面  
在网址栏里面输入http://192.168.78.143/index.html  
不断的刷新，界面会轮流显示 192.168.78.131和192.168.78.136  
在网址栏里面输入http://192.168.78.143/test.php  
不断的刷新，界面会轮流显示 192.168.78.131-php(包括php的界面)和192.168.78.136 -php(包含php的界面)  
在网址栏里面输入http://192.168.78.143/pic.jpg  
不断的刷新，界面会轮流显示 192.168.78.131里面的图片pic.jpg和192.168.78.136里面的图片pic.jpg,图片只是名字相同  
  
测试性能：  
ab -n 2000 -c 2000 [http://192.168.78.143/index.html][http_192.168.78.143_index.html] \#2000个请求，同时2000个并发  
会报错，因为进程的默认最大连接数是1024  
  
ulimit -a \#显示目前资源限的设置  
ulimit -u \#可以看到系统默认一个进程最多同时允许打开1024个文件  
ulimit -u '数值' \#可以设置最大的连接数

## 总结，扩展： ##

如果有tomcat,apache,squid 设置为如下：

\#vim /usr/local/nginx/conf/nginx.conf \# 在最后添加以下内容，定义服务器组

upstream tomcat\_servers\{  
server 192.168.78.131:8080;  
server 192.168.78.136:8080;  
server 192.168.78.135:8080;  
\}  
upstream apache\_servers\{  
server 192.168.78.131:80;  
server 192.168.78.136:80;  
server 192.168.78.135:80;  
\}  
upstream squid\_servers\{  
server 192.168.78.131:3128;  
server 192.168.78.136:3128;  
server 192.168.78.135:3128;  
\}

# 三，加入keepalived实现调度（如下面例子） #

拓扑  
  
\++++++++++++  
\+ Client + 192.168.122.1/24 (真实机做客户端)  
\++++++++++++  
|  
|  
\++++++++++++ 192.168.122.254/24  
\+ Nginx +  
\++++++++++++  
|  
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_|\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_  
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_|\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_|\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_  
| | | |  
\++++++++++++ ++++++++++++ ++++++++++++ ++++++++++++  
\+ HTML A + + HTML B + + PHP A + + PHP B +  
\++++++++++++ ++++++++++++ ++++++++++++ ++++++++++++  
eth0 192.168.122.10/24 eth0 192.168.122.20/24 eth0 192.168.122.30/24 eth0 192.168.122.40/24  
  
nginx dr director  
|  
\--------------------  
| |  
nginx nginx rs realserver  
  
  
给realserver安装nginx，作页面，启动服务，保证能正常访问  
  
HTML A & HTML B  
\[root@localhost ~\]\# yum install httpd  
分别创建测试页面 index.html ,开启服务  
  
PHP A & php B  
\[root@localhost ~\]\# yum install httpd  
分别创建测试页面 index.php ,开启服务  
  
  
安装配置Nginx  
\[root@localhost ~\]\# rpm -ivh nginx-0.6.36-1.el5.i386.rpm  
\[root@localhost ~\]\# vim /etc/nginx/nginx.conf  
location / \{  
root /usr/share/nginx/html;  
index index.html index.htm;  
if ($request\_uri ~\* \\.html$) \{  
proxy\_pass http://htmlserver;  
\}  
  
if ($request\_uri ~\* \\.php$) \{  
proxy\_pass http://phpserver;  
\}  
\}  
  
\[root@localhost ~\]\# vim /etc/nginx/conf.d/test.conf  
upstream htmlserver \{  
server 192.168.122.10;  
server 192.168.122.20;  
\}  
upstream phpserver \{  
server 192.168.122.30;  
server 192.168.122.40;  
\}  
  
\[root@localhost ~\]\# service nginx start  
  
  
在客户端访问 Nginx 测试  
\[root@localhost ~\]\# elinks –dump http:// 192.168.122.254  
\[root@localhost ~\]\# elinks –dump http:// 192.168.122.254/index.html  
\[root@localhost ~\]\# elinks –dump http:// 192.168.122.254/index.php  
  
===============================  
  
**upstream支持的负载均衡算法**(面试题)  
**轮询（默认）**: 可以通过weight指定轮询的权重，权重越大，被调度的次数越多 **rr round robin**  
权重:用数字 谁数字大谁权重就高 按比例 1 3  
rr  
wrr  
**ip\_hash**： 根据每个请求IP进行调度，可以解决session的问题，不能使用weight  
client\_ip 192.168.1.8 nginx反向 webserver1  
fair：  可以根据请求页面的大小和加载时间长短进行调度，使用第三方的upstream\_fair模块  
url\_hash： 按请求的url的hash进行调度，从而使每个url定向到同一服务器，使用第三方的hash模块  
  
upstream支持的状态参数  
down： 暂停对该服务器的调度  
backup: 类似于LVS Sorry Server，当所有的非backup的服务器故障  
max\_fails: 请求失败的次数，默认为1  
fail\_timeout: 在经历max\_fails次失败后，暂停服务的时间  
  
upstream tianyun.com \{  
\# ip\_hash;  
server 192.168.10.137 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.10.20 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.10.251 max\_fails=2 fail\_timeout=5 **down**;  
server 192.168.10.253 backup;  
\}  
  
注：当使用ip\_hash时，服务器状态不可使用weight和backup  
=================================================================================  
**Nginx实现七层的负载均衡**  
  
调度到同一组上游服务器  
=================================================================================  
  
拓扑结构  
  
\[**LB Nginx**\]  
192.168.1.2  
  
\[**httpd**\] \[**httpd**\] \[**httpd**\]  
192.168.1.3 192.168.1.4 192.168.1.5  
  
  
实施过程  
1. nginx  
http \{  
 **upstream httpservers \{  
server 192.168.1.3**:80 weight=1 max\_fails=2 fail\_timeout=2;  
**server 192.168.1.4**:80 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.1.5:80 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.1.100:80 backup;  
**\}  
  
location / \{  
proxy\_pass** http://httpservers;  
proxy\_next\_upstream error timeout invalid\_header http\_500 http\_502 http\_503 http\_504;  
 **\}**  
\}  
  
proxy\_next\_upstream：这个指令属于 http\_proxy 模块的，指定后端返回什么样的异常响应时，使用另一个realserver  
  
2.Apache LogFormat 可选  
LogFormat "%\{X-Real-IP\}i %l %u %t \\"%r\\" %>s %b \\"%\{Referer\}i\\" \\"%\{User-Agent\}i\\"" combined  
LogFormat "%h %l %u %t \\"%r\\" %>s %b" common  
LogFormat "%\{Referer\}i -> %U" referer  
LogFormat "%\{User-agent\}i" agent  
  
=================================================================================  
  
**Nginx实现七层的负载均衡**  
  
调度到不同组上游服务器  
1. 动静分离  
2. 网站进行分区  
=================================================================================  
  
拓扑结构  
  
\[**vip: 192.168.1.80**\]  
  
\[**LB1 Nginx**\] \[**LB2 Nginx**\]  
192.168.1.2 192.168.1.3  
  
\[**news**\] \[**milis**\] \[**videos**\] \[**images**\] \[**others**\]  
1.11 1.21 1.31 1.41 1.51  
1.12 1.22 1.32 1.42 1.52  
1.13 1.23 1.33 1.43 1.53  
... ... ... ... ...  
  
  
一、实施过程  
1. 根据站点分区进行调度  
http \{  
upstream news \{  
server 192.168.1.11:80 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.1.12:80 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.1.13:80 weight=2 max\_fails=2 fail\_timeout=2;  
\}  
  
upstream milis \{  
server 192.168.1.21:80 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.1.22:80 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.1.23:80 weight=2 max\_fails=2 fail\_timeout=2;  
\}  
  
upstream videos \{  
server 192.168.1.31:80 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.1.32:80 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.1.33:80 weight=2 max\_fails=2 fail\_timeout=2;  
\}  
  
upstream images \{  
server 192.168.1.41:80 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.1.42:80 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.1.43:80 weight=2 max\_fails=2 fail\_timeout=2;  
\}  
  
upstream others \{  
server 192.168.1.51:80 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.1.52:80 weight=2 max\_fails=2 fail\_timeout=2;  
server 192.168.1.53:80 weight=2 max\_fails=2 fail\_timeout=2;  
\}  
  
server \{  
location / \{  
proxy\_pass http://others;  
\}  
  
location /news \{  
proxy\_pass http://news;  
\}  
  
location /mili \{  
proxy\_pass http://milis;  
\}  
  
location ~\* \\.(wmv|mp4|rmvb)$ \{  
proxy\_pass http://videos;  
\}  
  
location ~\* \\.(png|gif|jpg)$ \{  
proxy\_pass http://images;  
\}  
\}  
  
  
2. 根据动静分离进行调度  
http \{  
upstream htmlservers \{  
server 192.168.1.3:80 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.1.4:80 weight=2 max\_fails=2 fail\_timeout=2;  
\}  
  
upstream phpservers \{  
server 192.168.1.3:80 weight=1 max\_fails=2 fail\_timeout=2;  
server 192.168.1.4:80 weight=2 max\_fails=2 fail\_timeout=2;  
\}  
  
server \{  
location ~\* \\.html$ \{  
proxy\_pass http://htmlservers;  
\}  
  
location ~\* \\.php$ \{  
proxy\_pass http://phpservers;  
\}  
\}  
\}  
  
  
二、Keepalived实现调度器HA  
注：主/备调度器均能够实现正常调度  
1. 主/备调度器安装软件  
\[root@master ~\]\# yum -y install ipvsadm keepalived  
\[root@backup ~\]\# yum -y install ipvsadm keepalived  
  
2. Keepalived  
Master   
\# vim /etc/keepalived/keepalived.conf  
! Configuration File for keepalived  
  
global\_defs \{  
router\_id director1 //辅助改为director2  
\}  
  
vrrp\_instance VI\_1 \{  
state BACKUP  
nopreempt  
interface eth0 //心跳接口，尽量单独连接心跳  
virtual\_router\_id 80 //MASTER,BACKUP一致  
priority 100 //辅助改为50  
advert\_int 1  
authentication \{  
auth\_type PASS  
auth\_pass 1111  
\}  
virtual\_ipaddress \{  
192.168.1.80  
\}  
\}  
  
BACKUP  
  
  
3. 启动KeepAlived（主备均启动）  
\# chkconfig keepalived on  
\# service keepalived start  
\# ip addr  
  
  
4. 扩展对调度器Nginx健康检查（可选）  
思路：  
让Keepalived以一定时间间隔执行一个外部脚本，脚本的功能是当Nginx失败，则关闭本机的Keepalived  
a. script  
\[root@master ~\]\# cat /etc/keepalived/check\_nginx\_status.sh  
\#!/bin/bash  
/usr/bin/curl -I http://localhost &>/dev/null  
if \[ $? -ne 0 \];then  
/etc/init.d/keepalived stop  
fi   
\[root@master ~\]\# chmod a+x /etc/keepalived/check\_nginx\_status.sh  
  
b. keepalived使用script  
! Configuration File for keepalived  
  
global\_defs \{  
router\_id director1  
\}  
  
vrrp\_script check\_nginx \{  
script "/etc/keepalived/check\_nginx\_status.sh"  
interval 5  
\}  
  
vrrp\_instance VI\_1 \{  
state BACKUP  
interface eth0  
nopreempt  
virtual\_router\_id 90  
priority 100  
advert\_int 1  
authentication \{  
auth\_type PASS  
auth\_pass tianyun  
\}  
virtual\_ipaddress \{  
192.168.1.80  
\}  
  
 track\_script \{  
check\_nginx  
\}  
\}  
  
\--------------------  
proxy\_pass  
后端服务器用的非php独立进程  
apache+php模块  
fastcgi\_pass  
后端服务器用的是php-fpm  
php-fpm(fastcgi形式的php)  
  
后端服务器部署详细过程：  
安装软件：  
\# yum install nginx php php-fpm -y  
\# vim /etc/nginx/nginx.conf //添加php配置  
在server里面添加如下配置：  
location ~ \\.php$ \{  
root html;  
fastcgi\_pass 127.0.0.1:9000;  
fastcgi\_index index.php;  
fastcgi\_param SCRIPT\_FILENAME **$document\_root**$fastcgi\_script\_name;  
include fastcgi\_params;  
\}  
  
修改php-fpm进程账户并开启php-fpm的进程： 端口是9000  
\#vim /etc/php-fpm.d/www.conf //修改如下参数，默认值是apache  
user = nginx  
group = nginx  
  
为什么设置成nginx:  
因为nginx.conf配置的账户为nginx  
  
\# systemctl start php-fpm  
  
  
前端nginx反向代理服务器：  
 upstream web \{  
server 10.0.0.21;  
server 10.0.0.22;  
\}  
upstream phpserver \{  
server 10.0.0.23;  
server 10.0.0.24;  
\} \#上面的配置写到http里面server外面  
  
server \{  
listen 80;  
server\_name www.baidu.com;  
location / \{ \#html的配置  
proxy\_pass http://web;  
\}  
  
location ~\* \\.php$ \{ \#php的配置  
proxy\_pass http://phpserver;  
\}

## 补充：（php节点的安装） ##

\#yum install epel-release -y  
\#yum nginx php php-fpm -y  
  
php-fpm是独立的php进程 端口：9000

#     #

[http_192.168.78.143_index.html]: http://192.168.78.143/index.html