Apache + Tomcat基于HTTP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、配置192.168.1.144节点的主机名：

# vim /etc/hosts --> 192.168.1.144 TomcatA.qiuyue.com TomcatA

# vim /etc/hostname --> TomcatA

# hostnamectl set-hostname TomcatA

# hostname TomcatA

# logout

Ctrl + Shift + r

# hostname

3、配置192.168.1.145节点的主机名：

# vim /etc/hosts --> 192.168.1.145 TomcatB.qiuyue.com TomcatB

# vim /etc/hostname --> TomcatB

# hostnamectl set-hostname TomcatB

# hostname TomcatB

# logout

Ctrl + Shift + r

# hostname

4、192.168.1.144节点自定义Tomcat Host虚拟主机：

# cd /usr/local/tomcat/conf

# cp server.xml server.xml.bak

# vim server.xml，在和之间新增如下代码：

name="TomcatA.qiuyue.com" appBase="/data/webapps" unpackWARs="true" autoDeploy="true">

docBase="ROOT" reloadable="true" />

directory="/data/logs" prefix="TomcatA_access_log" suffix=".txt" pattern="%h %l %u %t "%r" %s %b" />

5、192.168.1.145节点自定义Tomcat Host虚拟主机：

# cd /usr/local/tomcat/conf

# cp server.xml server.xml.bak

# vim server.xml，在和之间新增如下代码：

name="TomcatB.qiuyue.com" appBase="/data/webapps" unpackWARs="true" autoDeploy="true">

docBase="ROOT" reloadable="true" />

directory="/data/logs" prefix="TomcatB_access_log" suffix=".txt" pattern="%h %l %u %t "%r" %s %b" />

6、192.168.1.144节点创建如下目录及测试页：

# mkdir -pv /data/{webapps,logs}

# mkdir -pv /data/webapps/ROOT

# vim /data/webapps/ROOT/index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

color="red">TomcatA.qiuyue.com

<% session.setAttribute("qiuyue.com","qiuyue.com"); %>

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

7、192.168.1.145节点创建如下目录及测试页：

# mkdir -pv /data/{webapps,logs}

# mkdir -pv /data/webapps/ROOT

# vim /data/webapps/ROOT/index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

color="blue">TomcatB.qiuyue.com

<% session.setAttribute("qiuyue.com","qiuyue.com"); %>

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

8、192.168.1.144节点新增jvmRoute参数：# vim /usr/local/tomcat/conf/server.xml

修改为

jvmRoute="TomcatA">

9、192.168.1.145节点新增jvmRoute参数：# vim /usr/local/tomcat/conf/server.xml

修改为

jvmRoute="TomcatB">

10、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

11、配置192.168.1.143节点/etc/hosts文件：# vim /etc/hosts

192.168.1.144 TomcatA.qiuyue.com TomcatA

192.168.1.145 TomcatB.qiuyue.com TomcatB

12、在192.168.1.143节点中使用curl命令访问：

# curl http://TomcatA.qiuyue.com:8080         //能正常显示文本内容

# curl http://TomcatB.qiuyue.com:8080         //能正常显示文本内容

13、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 http://TomcatA.qiuyue.com:8080 loadfactor=1 route=TomcatA

BalancerMember http://TomcatB.qiuyue.com:8080 loadfactor=1 route=TomcatB

ServerName web.qiuyue.com

ProxyVia On

ProxyRequests Off

ProxyPreserveHost On

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 On：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/index.jsp，访问的是默认虚拟主机

（4）修改192.168.1.144节点Tomcat默认虚拟主机：

# catalina.sh stop

# vim server.xml

修改为

defaultHost="TomcatA.qiuyue.com" jvmRoute="TomcatA">

# catalina.sh configtest  # catalina.sh start  # ss -tunlp | grep -w :8080

（5）修改192.168.1.145节点Tomcat默认虚拟主机：

# catalina.sh stop

# vim server.xml

修改为

defaultHost="TomcatB.qiuyue.com" jvmRoute="TomcatB">

# catalina.sh configtest  # catalina.sh start  # ss -tunlp | grep -w :8080

（6）本地浏览器重新访问192.168.1.143/index.jsp

轮询显示，Session ID一直在变：

14、配置proxy_balancer_module内置的manager：# vim /etc/httpd/conf.d/vhosts.conf

BalancerMember http://TomcatA.qiuyue.com:8080 loadfactor=1 route=TomcatA

BalancerMember http://TomcatB.qiuyue.com:8080 loadfactor=1 route=TomcatB

ServerName web.qiuyue.com

ProxyVia On

ProxyRequests Off

ProxyPreserveHost On

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

15、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 http://TomcatA.qiuyue.com:8080 loadfactor=1 route=TomcatA

BalancerMember http://TomcatB.qiuyue.com:8080 loadfactor=1 route=TomcatB

ProxySet lbmethod=bybusyness stickysession=ROUTEID

ServerName web.qiuyue.com

ProxyVia On

ProxyRequests Off

ProxyPreserveHost On

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，即基于权重将统计请求个数进行调度；bytraffic则基于权重的流量计数调度；bybusyness通过考量每个后端服务器的当前负载进行调度。

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

本地浏览器访问：

192.168.1.143，无论如何刷新，页面都不会改变：

Google Chrome浏览器F12：

备注：关闭浏览器，重新打开并访问192.168.1.143，会基于新的Cookie值进行会话保持

192.168.1.143/balancer-manager