Apache+Tomcat负载均衡与群集

环境:
  • 操作系统均为:CentOS 5.1
  • Apache2.X服务器一台:IP地址192.168.232.4;安装路径/usr/local/apache
  • Tomcat6服务器一台:IP地址192.168.232.5;安装路径/usr/local/tomcat
  • Tomcat6服务器一台:IP地址192.168.232.6;安装路径/usr/local/tomcat
 
配置:
  1. Apache安装:
#./configure --prefix=/usr/local/apache --enable-modules=so --enable-mods-shared=all --enable-proxy --enable-proxy-connect --enable-proxy-ftp --enable-proxy-http --enable-proxy-ajp --enable-proxy-balancer --enable-rewrite
注释:激活tomcat集群需要的 enable-proxyenable-proxy-httpenable-proxy-connectenable-proxy-ajpenable-proxy-balancer,其中proxy-ajpproxy-balancer必须依赖proxy,如果是自定义的编译除了以上几个必须的模块外,mod_status也要编译进去,切记。enable-proxy-ftp可以不编译。
#make;make install
 
  1. 制作Apache启动项:
#cp support/apachectl /etc/rc.d/init.d/httpd
#vi /etc/rc.d/init.d/httpd
添加以下内容:(包括#号)
# Startup script for the Apache Web Server
# chkconfig: 2345 85 15
# description: Apache is a World Wide Web server .It is used to server
# HTML files and CGI.
# processname: httpd
# pidfile: /usr/local/apache/log/httpd.pid
# config: /usr/local/apache/conf/httpd.conf
增加服务项
#chkconfig --add httpd
#chmod 755 /etc/rc.d/init.d/httpd
#chkconfig --level 345 httpd on
 
  1. JDK安装:
#chmod a+x jdk-6u4-linux-i586-rpm.bin
#./jdk-6u4-linux-i586-rpm.bin
 
  1. JAVA环境变量设置:
#vi /etc/profile
在文件最后添加以下内容:
JAVA_HOME=/usr/java/jdk1.6.0_04
CLASSPATH=.:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar
PATH=$JAVA_HOME/bin:$PATH
CATALINA_HOME=/usr/local/tomcat
export JAVA_HOME CLASSPATH PATH CATALINA_HOME
执行如下命令使环境变量生效:
source /etc/profile
测试配置是否成功:
java version
 
  1. Tomcat安装:
#tar zxvf apache-tomcat-6.0.16.tar.gz
#mv apache-tomcat-6.0.16 /usr/local/tomcat
 
  1. Tomcat随机启动:
#vi /etc/rc.local
添加以下内容:
/usr/local/tomcat/bin/startup.sh
 
  1. tomcat6配置文件server.xml
<!-- You should set jvmRoute to support load-balancing via AJP ie :
<Engine name="Standalone" defaultHost="localhost" jvmRoute="jvm1">
-->
<Engine name="Catalina" defaultHost="localhost">
改成
 
<!-- You should set jvmRoute to support load-balancing via AJP ie :
-->
<Engine name="Standalone" defaultHost="localhost" jvmRoute="tomcatX">
<!--
<Engine name="Catalina" defaultHost="localhost">
-->
说明:
第一台tomcat就把jvmRoute="tomcat1"
第二台tomcat就把jvmRoute="tomcat2"
 
<!--
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
-->
去掉注释变为
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
***群集详细配置***
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
channelSendOptions="8">
 
<Manager className="org.apache.catalina.ha.session.DeltaManager"
expireSessionsOnShutdown="false"
notifyListenersOnReplication="true"/>
 
<Channel className="org.apache.catalina.tribes.group.GroupChannel">
<Membership className="org.apache.catalina.tribes.membership.McastService"
address="228.0.0.4"
port="45564"
frequency="500"
dropTime="3000"/>
<Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
address="auto"
port="4000"
autoBind="100"
selectorTimeout="5000"
maxThreads="6"/>
 
<Sender className="org.apache.catalina.tribes.transport.ReplicationTransmitter">
<Transport className="org.apache.catalina.tribes.transport.nio.PooledParallelSender"/>
</Sender>
<Interceptor className="org.apache.catalina.tribes.group.interceptors.TcpFailureDetector"/>
<Interceptor className="org.apache.catalina.tribes.group.interceptors.MessageDispatch15Interceptor"/>
</Channel>
 
<Valve className="org.apache.catalina.ha.tcp.ReplicationValve"
filter=""/>
<Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/>
 
<Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer"
tempDir="/tmp/war-temp/"
deployDir="/tmp/war-deploy/"
watchDir="/tmp/war-listen/"
watchEnabled="false"/>
 
<ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/>
<ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/>
</Cluster>
 
  1. 配置应用的web.xml
在每个webapps应用中,修改配置文件web.xml文件 添加元素<distributable/>
web.xml文件中<web-app>元素下增加以下内容:
<!--此应用将与群集服务器复制Session-->
<distributable/>
具体修改如下:
修改前:
<?xml version="1.0" encoding="ISO-8859-1"?>
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee [url]http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd[/url]"
version="2.5">
</web-app>
修改后:
<?xml version="1.0" encoding="ISO-8859-1"?>
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee [url]http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd[/url]"
version="2.5">
<!--此应用将与群集服务器复制Session-->
<distributable/>
</web-app>
  1. 配置apacheajp负载均衡功能:
确保将以下Module的注释去掉
LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_connect_module modules/mod_proxy_connect.so
LoadModule proxy_ftp_module modules/mod_proxy_ftp.so
LoadModule proxy_http_module modules/mod_proxy_http.so
LoadModule proxy_ajp_module modules/mod_proxy_ajp.so
LoadModule proxy_balancer_module modules/mod_proxy_balancer.so
LoadModule status_module modules/mod_status.so
增加以下内容:
# Proxypass Config
Include conf/extra/httpd-modproxy.conf
建立文件httpd-modproxy.conf输入内容:
<Location /server-status>
SetHandler server-status
Order Deny,Allow
Deny from all
Allow from all
</Location>
<Location /balancer-manager>
SetHandler balancer-manager
Order Deny,Allow
Deny from all
Allow from all
</Location>
ProxyRequests Off
ProxyPass / balancer://tomcatcluster stickysession=jsessionid nofailover=On
 
<Proxy balancer://tomcatcluster>
BalancerMember [url]http://192.168.232.5:8080[/url] loadfactor=1
BalancerMember [url]http://192.168.232.6:8080[/url] loadfactor=2
</Proxy>
注释:
  • ProxyRequests Off 表示启用反向代理,必须开启;
  • ProxyPass为代理转发的Url,即将所有访问/的请求转发到群集balancer://tomcatcluster,这里为/即将所有访问/的请求转发到群集balancer://tomcatcluster/test目录;
  • BalancerMember为群集的成员,即群集服务器12,负载均衡服务器会根据均衡规则来将请求转发给BalancerMember
 
  1. 调试负载均衡集群系统:
访问apache服务器的web服务:[url]http://192.168.232.4/balancer-manager[/url]
如果显示负载均衡有关信息则说明成功了,接着可以访问[url]http://192.168.232.4/[/url]即访问到了tomcat的应用
***必须先启动Tomcat服务再启动Apache服务!***
 
参考文档:
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