早前就解了Apache和Tomcat可以搭建集群,可以负载均衡,升级就不需要停交易,真是强大。昨晚看了google reader的收藏又再次看到这篇文章,于是今天在星巴克研究了一把,发现真的很强大,负载均衡、session复制都可以做到,以后再也不用为升级系统而烦恼了。
下面就来讲讲是搭建集群的过程,首页需要下载apahce和tomcat(当然需要安装jdk,这就不多讲了,大家应该懂得),本次实践我是在windows系统的环境下进行的,apache是2.2.21版本,tomcat是7.0.16和7.0.23两个版本。
首先讲讲tomcat需要配置的文件,假设Tomcat 7.0.16为服务器A,Tomcat 7.0.23为服务器B。注意如果你的Tomcat都是放在同一台机子上,那你要修改端口,确保端口不要冲突。
服务器A的server.xml配置文件中的Engine节点中新增jvmRoute属性,值可以自己定义,例如jvm1,同时新增Cluster节点的所有内容,如果tomcat是在同一台机子的就需要注意Receiver节点的port属性不能冲突,例如:4000
服务器A的server.xml配置文件
<Connector port="8080" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" /> <Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1"> <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster" hannelSendOptions="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"/> <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"/> </Channel> </Cluster> ...... </Engine>
服务器B的server.xml配置文件,其中不同的是8180、8109和4001的几个端口的修改和jvmRoute值的不同,其它都一样
<Connector port="8180" protocol="HTTP/1.1" connectionTimeout="20000" redirectPort="8443" /> <Connector port="8109" protocol="AJP/1.3" redirectPort="8443" /> <Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm2"> <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster" hannelSendOptions="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="4001" 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"/> <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"/> </Channel> </Cluster> ...... </Engine>
tomcat配置好了,为了session复制,我们还需要在应用的web.xml文件中添加<distributeable/>这个一个配置,那接下来我们就来讲讲apache的配置,需要修改apache的httpd.conf文件,将去掉一下这些的注释,使其生效
Include conf/extra/httpd-vhosts.conf LoadModule negotiation_module modules/mod_negotiation.so LoadModule proxy_module modules/mod_proxy.so LoadModule proxy_ajp_module modules/mod_proxy_ajp.so LoadModule proxy_balancer_module modules/mod_proxy_balancer.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
在http.conf的最后面新增以下配置,使apache可以反向代理和负载均衡,注意这里的端口是tomcat的端口,同时route是刚才配置的jvmRoute的值,不能配错
ProxyRequests Off <proxy balancer://loadbalancer> BalancerMember http://127.0.0.1:8080 loadfactor=1 route=jvm1 BalancerMember http://127.0.0.1:8180 loadfactor=1 route=jvm2 </proxy>
下面是httpd-vhosts.conf文件的配置,其它就不多讲了,"ProxyPass /google !"是可以配置/google地址不反向代理,那么输入地址/google就会在你apahce的根目录里面找,"/baidu" 是配置了方向代理到百度,以上这两个配置主要是看个人需求,主要是想说明怎么配置方向代理,而"ProxyPass / balancer://loadbalancer/ stickysession=jsessionid nofailover=On" 这两句才是重点,主要是配置“/”都反向代理到tomcat,并且是负载均衡的模式
<VirtualHost *:80> ServerAdmin [email protected] DocumentRoot "D:/Program Files/Apache Software Foundation/Apache2.2/docs/dummy-host.xiaoyang.com" ServerName dummy-host.xiaoyang.com ServerAlias www.dummy-host.xiaoyang.com ErrorLog "logs/dummy-host.xiaoyang.com-error.log" CustomLog "logs/dummy-host.xiaoyang.com-access.log" common ProxyPass /google ! ProxyPass /baidu http://www.baidu.com ProxyPassReverse /baidu http://www.baidu.com ProxyPass / balancer://loadbalancer/ stickysession=jsessionid nofailover=On ProxyPassReverse / balancer://loadbalancer/ </VirtualHost>
好了这就完成了,然后就可以打开你的apache的地址了,你不停的刷新页面,会被负载分配到两个tomcat服务其上面其,同时会话是相同的。