437 lines
14 KiB
Markdown
437 lines
14 KiB
Markdown
# Nginx动静分离+负载均衡
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x86
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windows linux 部分unix
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小型机
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IBM HP 安装不了普通的操作系统（windows linux）
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只能安装厂商自身提供的UNIX系统
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常见的Unix系统：IBM的AIX HP的HP-UX 这些系统只能安装在他们自身厂商的小型机上
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大型机
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国企 还不是一般的国企 搞科研 真正的高科技 航天 军工 导弹
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集群的分类：cluster
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高可用集群 HA high availability
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避免单节点故障
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软件：keepalived
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负载均衡集群 **LB** **load balance**
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提高负载，提高并发量
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软件：nginx反向代理(7层) lvs(4层) haproxy(7层)
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硬件：硬件负载均衡器 F5(BigIP)和redware
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HPC高性能运算集群
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分布式存储集群
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极大的提升存储容量，提供数据高可用，保证数据安全
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软件：ceph glusterfs hdfs
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存储分类：NAS SAN DAS
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Nginx proxy 是 Nginx 的王牌功能,利用 proxy 基本可以实现一个完整的 7 层负载均衡。
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1. 功能强大,性能卓越,运行稳定。
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2. 配置简单灵活。
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3. 能够自动剔除工作不正常的后端服务器。
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4. 上传文件使用异步模式。
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5. 支持多种分配策略,可以分配权重,分配方式灵活。
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lvs和nginx组合代理负载均衡 面试题(lvs和nginx的区别)
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nginx用来做http的反向代理，能够upsteam实现http请求的多种方式的均衡转发。由于采用的是**异步转发可以做到如果一个服务器请求失败，立即切换到其他服务器，直到请求成功或者最后一台服务器失败为止**。这可以最大程度的提高系统的请求成功率。
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lvs采用的是**同步请求转发**的策略。这里说一下同步转发和异步转发的区别。同步转发是在lvs服务器接收到请求之后，立即redirect到一个后端服务器，由客户端直接和后端服务器建立连接。**异步转发**是nginx在保持客户端连接的同时，发起一个相同内容的新请求到后端，等后端返回结果后，由nginx返回给客户端。
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进一步来说：当做为负载均衡服务器的nginx和lvs处理相同的请求时，所有的请求和响应流量都会经过nginx；但是使用lvs时，仅请求流量经过lvs的网络，响应流量由后端服务器的网络返回。
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也就是，当作为后端的服务器规模庞大时，nginx的网络带宽就成了一个巨大的瓶颈。
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但是仅仅使用lvs作为负载均衡的话，一旦后端接受到请求的服务器出了问题，那么这次请求就失败了。但是如果在lvs的后端在添加一层nginx（多个），每个nginx后端再有几台应用服务器，那么结合两者的优势，既能避免单nginx的流量集中瓶颈，又能避免单lvs时一锤子买卖的问题。
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lvs/dr 同步传输
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nginx 异步传输
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**拓扑**
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[]()
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**环境**
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1. 修改主机名称
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2. 名称解析
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3. ip互通 所有机器全部在同一个网段
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4. 关闭防火墙和selinux
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5 . HTML A & HTML B
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```bash
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[root@localhost ~]# yum install httpd -y
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分别创建测试页面 index.html 开启服务
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```
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6. PHP A & PHP B
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```bash
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[root@localhost ~]# yum install httpd php -y
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分别创建测试页面 index.php 开启服务
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<?php
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print "hello A";
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phpinfo();
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?>
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```
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7. 测试4台真实服务器的页面是否能正常访问
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8. 安装配置负载均衡器上的Nginx（负载均衡器、分发器、反向代理）
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```bash
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# yum install nginx -y
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# vim /etc/nginx/nginx.conf
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location / {
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root /usr/share/nginx/html;
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index index.html index.htm;
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if ($request_uri ~* \.html$) {
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proxy_pass http://htmlserver;
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}
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if ($request_uri ~* \.php$) {
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proxy_pass http://phpserver;
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}
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}
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# vim /etc/nginx/conf.d/test.conf
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upstream htmlserver {
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server 192.168.122.10;
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server 192.168.122.20;
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}
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upstream phpserver {
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server 192.168.122.30;
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server 192.168.122.40;
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}
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# systemctl restart nginx
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```
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在客户端访问 Nginx 测试
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```bash
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# elinks --dump http:// 192.168.122.254
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# elinks --dump http:// 192.168.122.254/index.html
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# elinks --dump http:// 192.168.122.254/index.php
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```
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**upstream支持的负载均衡算法**(面试题)
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**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**
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权重:用数字 谁数字大谁权重就高 按比例 1 3
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rr
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wrr
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**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
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client_ip 192.168.1.8 nginx反向 webserver1
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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
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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
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**upstream支持的状态参数**
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```
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down： 暂停对该服务器的调度
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backup: 类似于LVS Sorry Server，当所有的非backup的服务器故障
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max_fails: 请求失败的次数，默认为1
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fail_timeout: 在经历max_fails次失败后，暂停服务的时间
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```
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upstream htmlservers {
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```bash
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# ip_hash;
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server 192.168.10.137 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.10.20 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.10.251 max_fails=2 fail_timeout=5 **down**;
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server 192.168.10.253 backup;
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}
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```
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注：当使用ip_hash时，服务器状态不可使用weight和backup
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**Nginx实现七层的负载均衡**
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调度到同一组上游服务器
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**拓扑结构**
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[**LB Nginx**]
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192.168.1.2
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[**httpd**] [**httpd**] [**httpd**]
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192.168.1.3 192.168.1.4 192.168.1.5
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**实施过程**
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\1. nginx
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http {
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**upstream httpservers {
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server 192.168.1.3**:80 weight=1 max_fails=2 fail_timeout=2;
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**server 192.168.1.4**:80 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.1.5:80 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.1.100:80 backup;
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**}**
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**location / {
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proxy_pass** http://httpservers;
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proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
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**}**
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}
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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
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\2. Apache LogFormat 可选
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LogFormat "%{X-Real-IP}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
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LogFormat "%h %l %u %t \"%r\" %>s %b" common
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LogFormat "%{Referer}i -> %U" referer
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LogFormat "%{User-agent}i" agent
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=================================================================================
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**Nginx实现七层的负载均衡**
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调度到不同组上游服务器
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\1. 动静分离
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\2. 网站进行分区
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=================================================================================
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**拓扑结构**
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[**vip: 192.168.1.80**]
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[**LB1 Nginx**] [**LB2 Nginx**]
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192.168.1.2 192.168.1.3
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[**news**] [**milis**] [**videos**] [**images**] [**others**]
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1.11 1.21 1.31 1.41 1.51
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1.12 1.22 1.32 1.42 1.52
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1.13 1.23 1.33 1.43 1.53
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... ... ... ... ...
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**一、实施过程**
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\1. 根据站点分区进行调度
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http {
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upstream news {
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server 192.168.1.11:80 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.1.12:80 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.1.13:80 weight=2 max_fails=2 fail_timeout=2;
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}
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upstream milis {
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server 192.168.1.21:80 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.1.22:80 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.1.23:80 weight=2 max_fails=2 fail_timeout=2;
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}
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upstream videos {
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server 192.168.1.31:80 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.1.32:80 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.1.33:80 weight=2 max_fails=2 fail_timeout=2;
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}
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upstream images {
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server 192.168.1.41:80 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.1.42:80 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.1.43:80 weight=2 max_fails=2 fail_timeout=2;
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}
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upstream others {
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server 192.168.1.51:80 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.1.52:80 weight=2 max_fails=2 fail_timeout=2;
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server 192.168.1.53:80 weight=2 max_fails=2 fail_timeout=2;
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}
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server {
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location / {
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proxy_pass http://others;
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}
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location /news {
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proxy_pass http://news;
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}
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location /mili {
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proxy_pass http://milis;
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}
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location ~* \.(wmv|mp4|rmvb)$ {
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proxy_pass http://videos;
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}
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location ~* \.(png|gif|jpg)$ {
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proxy_pass http://images;
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}
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}
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\2. 根据动静分离进行调度
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http {
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upstream htmlservers {
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server 192.168.1.3:80 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.1.4:80 weight=2 max_fails=2 fail_timeout=2;
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}
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upstream phpservers {
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server 192.168.1.3:80 weight=1 max_fails=2 fail_timeout=2;
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server 192.168.1.4:80 weight=2 max_fails=2 fail_timeout=2;
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}
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server {
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location ~* \.html$ {
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proxy_pass http://htmlservers;
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}
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location ~* \.php$ {
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proxy_pass http://phpservers;
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}
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}
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}
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二、Keepalived实现调度器HA
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注：主/备调度器均能够实现正常调度
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\1. 主/备调度器安装软件
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[root@master ~]# yum -y install ipvsadm keepalived
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[root@backup ~]# yum -y install ipvsadm keepalived
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\2. Keepalived
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**Master**
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\# vim /etc/keepalived/keepalived.conf
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! Configuration File for keepalived
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global_defs {
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router_id director1 //辅助改为director2
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}
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vrrp_instance VI_1 {
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state BACKUP
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nopreempt
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interface eth0 //心跳接口，尽量单独连接心跳
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virtual_router_id 80 //MASTER,BACKUP一致
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priority 100 //辅助改为50
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advert_int 1
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authentication {
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auth_type PASS
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auth_pass 1111
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}
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virtual_ipaddress {
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192.168.1.80
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}
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}
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**BACKUP**
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\3. 启动KeepAlived（主备均启动）
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\# chkconfig keepalived on
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\# service keepalived start
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\# ip addr
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\4. 扩展对调度器Nginx健康检查（可选）
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思路：
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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
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a. script
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[root@master ~]# cat /etc/keepalived/check_nginx_status.sh
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\#!/bin/bash
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/usr/bin/curl -I http://localhost &>/dev/null
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if [ $? -ne 0 ];then
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/etc/init.d/keepalived stop
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fi
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[root@master ~]# chmod a+x /etc/keepalived/check_nginx_status.sh
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b. keepalived使用script
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! Configuration File for keepalived
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global_defs {
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router_id director1
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}
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vrrp_script check_nginx {
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script "/etc/keepalived/check_nginx_status.sh"
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interval 5
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}
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vrrp_instance VI_1 {
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state BACKUP
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interface eth0
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nopreempt
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virtual_router_id 90
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priority 100
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advert_int 1
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authentication {
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auth_type PASS
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auth_pass tianyun
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}
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virtual_ipaddress {
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192.168.1.80
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}
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track_script {
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check_nginx
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}
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}
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\--------------------
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proxy_pass
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后端服务器用的非php独立进程
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apache+php模块
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fastcgi_pass
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后端服务器用的是php-fpm
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php-fpm(fastcgi形式的php)
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后端服务器部署详细过程：
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安装软件：
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\# yum install nginx php php-fpm -y
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\# vim /etc/nginx/nginx.conf //添加php配置
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在server里面添加如下配置：
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location ~ \.php$ {
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root html;
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fastcgi_pass 127.0.0.1:9000;
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fastcgi_index index.php;
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fastcgi_param SCRIPT_FILENAME **$document_root**$fastcgi_script_name;
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include fastcgi_params;
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}
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修改php-fpm进程账户并开启php-fpm的进程： 端口是9000
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\#vim /etc/php-fpm.d/www.conf //修改如下参数，默认值是apache
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user = nginx
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group = nginx
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为什么设置成nginx:
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因为nginx.conf配置的账户为nginx
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\# systemctl start php-fpm
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前端nginx反向代理服务器：
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upstream web {
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server 10.0.0.21;
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server 10.0.0.22;
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}
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upstream phpserver {
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server 10.0.0.23;
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server 10.0.0.24;
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} #上面的配置写到http里面server外面
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server {
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listen 80;
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server_name www.baidu.com;
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location / { #html的配置
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proxy_pass http://web;
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}
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location ~* \.php$ { #php的配置
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proxy_pass http://phpserver;
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} |