1、演示环境：
IP |
操作系统 |
部署程序 |
192.168.1.143 |
CentOS 7.6 |
Apache |
192.168.1.144 |
CentOS 7.6 |
Tomcat |
192.168.1.145 |
CentOS 7.6 |
Tomcat |
2、192.168.1.144节点创建测试页：
# vim /usr/local/tomcat/webapps/ROOT/test.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
<head><title>TomcatA</title></head>
<body>
<h1><font color="red">TomcatA</font></h1>
<table border="1">
<tr>
<td>Session ID</td>
<td><%= session.getId() %></td>
</tr>
<tr>
<td>Created ON</td>
<td><%= session.getCreationTime() %></td>
</tr>
</table>
</body>
</html>
3、192.168.1.145节点创建测试页：
# vim /usr/local/tomcat/webapps/ROOT/test.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
<head><title>TomcatB</title></head>
<body>
<h1><font color="blue">TomcatB</font></h1>
<table border="1">
<tr>
<td>Session ID</td>
<td><%= session.getId() %></td>
</tr>
<tr>
<td>Created ON</td>
<td><%= session.getCreationTime() %></td>
</tr>
</table>
</body>
</html>
4、192.168.1.144节点新增jvmRoute参数：
# cd /usr/local/tomcat/conf
# cp server.xml server.xml.bak
# vim server.xml
<Engine name="Catalina" defaultHost="localhost">修改为
<Engine name="Catalina" defaultHost="localhost" jvmRoute="TomcatA">
5、192.168.1.145节点新增jvmRoute参数：
# cd /usr/local/tomcat/conf
# cp server.xml server.xml.bak
# vim server.xml
<Engine name="Catalina" defaultHost="localhost">修改为
<Engine name="Catalina" defaultHost="localhost" jvmRoute="TomcatB">
6、分别启动192.168.1.144节点和192.168.1.145节点上的Tomcat：
# catalina.sh stop # catalina.sh configtest # catalina.sh start # ss -tunlp | grep -w :8080
7、在192.168.1.143节点中使用curl命令访问：
# curl http://192.168.1.144:8080/test.jsp //能正常显示文本内容
# curl http://192.168.1.145:8080/test.jsp //能正常显示文本内容
8、192.168.1.143节点安装Apache实现反代、动静分离和负载均衡：
# yum -y install httpd
# cd /etc/httpd/conf
# cp httpd.conf httpd.conf.bak
# vim httpd.conf
Ø 新增代码：ServerName localhost:80
Ø 注释代码：DocumentRoot "/var/www/html"
# httpd -t # systemctl start httpd.service # ss -tunlp | grep -w :80
# httpd -M | grep proxy
（1）配置status状态页面：
# vim /etc/httpd/conf/httpd.conf，末尾新增如下代码：
<Location /server-status>
SetHandler server-status
Require all granted
</Location>
备注：此处未做访问控制，status状态页面用于测试反代功能
# httpd -t # systemctl reload httpd.service # ss -tunlp | grep -w :80
本地浏览器访问：
192.168.1.143
192.168.1.143/server-status
（2）配置虚拟主机：# vim /etc/httpd/conf.d/vhosts.conf
<Proxy balancer://testcluster>
BalancerMember ajp://192.168.1.144:8009 loadfactor=1 route=TomcatA
BalancerMember ajp://192.168.1.145:8009 loadfactor=1 route=TomcatB
</Proxy>
<VirtualHost *:80>
ServerName web.qiuyue.com
ProxyVia On
ProxyRequests Off
ProxyPreserveHost Off
<Proxy *>
Require all granted
</Proxy>
ProxyPass /server-status !
ProxyPass / balancer://testcluster/
ProxyPa***everse / balancer://testcluster/
<Location />
Require all granted
</Location>
</VirtualHost>
# httpd -t # systemctl reload httpd.service # ss -tunlp | grep -w :80
备注：常用指令说明
Ø ProxyVia On：每个请求和响应报文的HTTP首部均添加Via，用于在多级代理中控制代理请求的流向
Ø ProxyRequests Off：关闭Apache正向代理功能，开启反代功能必须关闭正向代理功能
Ø ProxyPreserveHost Off：启用此功能，代理会将用户请求报文中的Host:行发送给后端服务器，而不再使用ProxyPass指定的服务器地址，如果想在反代中支持虚拟主机，则需要开启此项
Ø ProxyPass PATH !|URL：将后端服务器某URL与当前服务器的某虚拟路径关联起来作为提供服务的路径，PATH为当前服务器上的某虚拟路径，URL为后端服务器上某URL路径，使用此指令时必须将ProxyRequests的值设置为Off，而且如果PATH以/结尾，则对应的URL也必须以/结尾，反之亦然
Ø ProxyPa***everse：让Apache调整HTTP重定向响应报文中的Location、Content-Location及URI标签所对应的URL，在反代环境中必须使用此指令避免重定向报文绕过Proxy服务器
（3）本地浏览器访问：
192.168.1.143
192.168.1.143/server-status
192.168.1.143/test.jsp
轮询显示，且Session ID一直在变：
9、 配置proxy_balancer_module内置的Load Balancer Manager：# vim /etc/httpd/conf.d/vhosts.conf
<Proxy balancer://testcluster>
BalancerMember ajp://192.168.1.144:8009 loadfactor=1 route=TomcatA
BalancerMember ajp://192.168.1.145:8009 loadfactor=1 route=TomcatB
</Proxy>
<VirtualHost *:80>
ServerName web.qiuyue.com
ProxyVia On
ProxyRequests Off
ProxyPreserveHost Off
<Proxy *>
Require all granted
</Proxy>
ProxyPass /server-status !
ProxyPass /balancer-manager !
ProxyPass / balancer://testcluster/
ProxyPa***everse / balancer://testcluster/
<Location />
Require all granted
</Location>
<Location /balancer-manager>
SetHandler balancer-manager
Require all granted
</Location>
</VirtualHost>
# httpd -t # systemctl reload httpd.service # ss -tunlp | grep -w :80
本地浏览器访问：192.168.1.143/balancer-manager
10、实现session会话保持：# vim /etc/httpd/conf.d/vhosts.conf
<Proxy balancer://testcluster>
BalancerMember ajp://192.168.1.144:8009 loadfactor=1 route=TomcatA
BalancerMember ajp://192.168.1.145:8009 loadfactor=1 route=TomcatB
ProxySet lbmethod=bytraffic stickysession=ROUTEID
</Proxy>
<VirtualHost *:80>
ServerName web.qiuyue.com
ProxyVia On
ProxyRequests Off
ProxyPreserveHost Off
<Proxy *>
Require all granted
</Proxy>
ProxyPass /server-status !
ProxyPass /balancer-manager !
ProxyPass / balancer://testcluster/
ProxyPa***everse / balancer://testcluster/
<Location />
Require all granted
</Location>
<Location /balancer-manager>
SetHandler balancer-manager
Require all granted
</Location>
</VirtualHost>
备注：lbmethod为Apache实现负载均衡的调度方法，默认为byrequests，即基于请求次数进行调度；bytraffic为基于流量进行调度；bybusyness为基于繁忙程序进行调度。
# httpd -t # systemctl reload httpd.service # ss -tunlp | grep -w :80
本地浏览器访问：
192.168.1.143/test.jsp，无论如何刷新，页面都不会改变：
360安全浏览器F12：
备注：关闭浏览器，重新打开并访问192.168.1.143/test.jsp，会基于新的Cookie进行会话保持
192.168.1.143/balancer-manager
