Apache + Tomcat基于AJP协议实现反代、动静分离、负载均衡和session会话保持

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"%>

color="red">TomcatA

Session ID	<%= session.getId() %>
Created ON	<%= session.getCreationTime() %>

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"%>

color="blue">TomcatB

Session ID	<%= session.getId() %>
Created ON	<%= session.getCreationTime() %>

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

修改为

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

修改为

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 :8009

7、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：

SetHandler server-status

Require all granted

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

BalancerMember ajp://192.168.1.144:8009 loadfactor=1 route=TomcatA

BalancerMember ajp://192.168.1.145:8009 loadfactor=1 route=TomcatB

ServerName web.qiuyue.com

ProxyVia On

ProxyRequests Off

ProxyPreserveHost Off

Require all granted

ProxyPass /server-status !

ProxyPass / balancer://testcluster/

ProxyPa***everse / balancer://testcluster/

Require all granted

# 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：

8、 配置proxy_balancer_module内置的Load Balancer Manager：# vim /etc/httpd/conf.d/vhosts.conf

BalancerMember ajp://192.168.1.144:8009 loadfactor=1 route=TomcatA

BalancerMember ajp://192.168.1.145:8009 loadfactor=1 route=TomcatB

ServerName web.qiuyue.com

ProxyVia On

ProxyRequests Off

ProxyPreserveHost Off

Require all granted

ProxyPass /server-status !

ProxyPass /balancer-manager !

ProxyPass / balancer://testcluster/

ProxyPa***everse / balancer://testcluster/

Require all granted

SetHandler balancer-manager

Require all granted

# httpd -t  # systemctl reload httpd.service  # ss -tunlp | grep -w :80

本地浏览器访问：192.168.1.143/balancer-manager

9、实现session会话保持：# vim /etc/httpd/conf.d/vhosts.conf

Header add Set-Cookie "ROUTEID=.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED

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

ServerName web.qiuyue.com

ProxyVia On

ProxyRequests Off

ProxyPreserveHost Off

Require all granted

ProxyPass /server-status !

ProxyPass /balancer-manager !

ProxyPass / balancer://testcluster/

ProxyPa***everse / balancer://testcluster/

Require all granted

SetHandler balancer-manager

Require all granted

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