操作目的
前端的web服務器接收請求,若是jsp頁面,就通過mod_jk/mod_proxy連接器轉發至後端的tomcat服務器,並實現tomcat的負載均衡,session會話的保持
簡單拓撲圖
準備工作:
兩臺服務器
172.16.220.11 安裝httpd tomcat 把web服務器和tomcat做在一臺服務器上 主機名爲tomcat1
172.16.220.12 安裝tomcat 做爲tomcat服務器 主機名爲tomcat2
同步兩臺服務器的時間
hwclock -s
一、準備兩臺服務器
- tomcat1
- 編譯安裝httpd
- 準備的包apr-1.4.6.tar.bz2 apr-util-1.4.1.tar.bz2 httpd-2.4.2.tar.bz2
- 安裝apr
- #tar xf apr-1.4.6.tar.bz2
- #cd apr-1.4.6
- #./configure --prefix=/usr/local/apr
- #make
- #make install
- #tar xf apr-util-1.4.1.tar.bz2
- #cd apr-util-1.4.1
- #./configure --prefix=/usr/local/apr-util --with-apr=/usr/local/apr
- #make
- #make install
- 編譯安裝apache
- (注意:編譯的時候要啓用--enable-so 指定apr的位置 啓用--enable-proxy --enable-proxy-http --enable-proxy=ajp模塊)
- #yum -y install pcre-devel
- #tar xf httpd-2.4.2.tar.bz2
- #cd httpd-2.4.2
- #./configure --prefix=/usr/local/apache --sysconfdir=/etc/httpd --enable-so --enable-sll --enable-zlib --enable-cgi --enable-rewrite --with-zlib --with-pcre --with-apr=/usr/local/apr --with-apr-util=/usr/local/apr-util --enable-proxy --enable-proxy-http --enable-proxy-ajp
- #make
- #make install
添加PidFile文件
- #vim /etc/httpd/httpd.conf
- 添加
- PidFile "/var/run/httpd.pid"
提供服務腳本編輯/etc/rc.d/init.d/httpd
- #!/bin/bash
- #
- # httpd Startup script for the Apache HTTP Server
- #
- # chkconfig: - 85 15
- # description: Apache is a World Wide Web server. It is used to serve \
- # HTML files and CGI.
- # processname: httpd
- # config: /etc/httpd/conf/httpd.conf
- # config: /etc/sysconfig/httpd
- # pidfile: /var/run/httpd.pid
- # Source function library.
- . /etc/rc.d/init.d/functions
- if [ -f /etc/sysconfig/httpd ]; then
- . /etc/sysconfig/httpd
- fi
- # Start httpd in the C locale by default.
- HTTPD_LANG=${HTTPD_LANG-"C"}
- # This will prevent initlog from swallowing up a pass-phrase prompt if
- # mod_ssl needs a pass-phrase from the user.
- INITLOG_ARGS=""
- # Set HTTPD=/usr/sbin/httpd.worker in /etc/sysconfig/httpd to use a server
- # with the thread-based "worker" MPM; BE WARNED that some modules may not
- # work correctly with a thread-based MPM; notably PHP will refuse to start.
- # Path to the apachectl script, server binary, and short-form for messages.
- apachectl=/usr/local/apache/bin/apachectl
- httpd=${HTTPD-/usr/local/apache/bin/httpd}
- prog=httpd
- pidfile=${PIDFILE-/var/run/httpd.pid}
- lockfile=${LOCKFILE-/var/lock/subsys/httpd}
- RETVAL=0
- start() {
- echo -n $"Starting $prog: "
- LANG=$HTTPD_LANG daemon --pidfile=${pidfile} $httpd $OPTIONS
- RETVAL=$?
- echo
- [ $RETVAL = 0 ] && touch ${lockfile}
- return $RETVAL
- }
- stop() {
- echo -n $"Stopping $prog: "
- killproc -p ${pidfile} -d 10 $httpd
- RETVAL=$?
- echo
- [ $RETVAL = 0 ] && rm -f ${lockfile} ${pidfile}
- }
- reload() {
- echo -n $"Reloading $prog: "
- if ! LANG=$HTTPD_LANG $httpd $OPTIONS -t >&/dev/null; then
- RETVAL=$?
- echo $"not reloading due to configuration syntax error"
- failure $"not reloading $httpd due to configuration syntax error"
- else
- killproc -p ${pidfile} $httpd -HUP
- RETVAL=$?
- fi
- echo
- }
- # See how we were called.
- case "$1" in
- start)
- start
- ;;
- stop)
- stop
- ;;
- status)
- status -p ${pidfile} $httpd
- RETVAL=$?
- ;;
- restart)
- stop
- start
- ;;
- condrestart)
- if [ -f ${pidfile} ] ; then
- stop
- start
- fi
- ;;
- reload)
- reload
- ;;
- graceful|help|configtest|fullstatus)
- $apachectl $@
- RETVAL=$?
- ;;
- *)
- echo $"Usage: $prog {start|stop|restart|condrestart|reload|status|fullstatus|graceful|help|configtest}"
- exit 1
- esac
- exit $RETVAL
- #chmod +x /etc/rc.d/init.d/httpd
- #chkconfig --add httpd
- #service httpd start
- 添加apache的路徑
- #vim /etc/profile
- PATH:$PATH:/usr/local/apache/bin
- 而後重新載入/etc/profile
- #. /etc/profile
- # httpd -D DUMP_MODULES | grep proxy //查看加載的模塊
- proxy_http_module (shared)
- proxy_fcgi_module (shared)
- proxy_scgi_module (shared)
- proxy_ajp_module (shared)
- tomcat1 tomcat2
- 安裝tomcat
- # rpm -ivh jdk-7u5-linux-i586.rpm
- 爲JVM指定JDK路徑
- #vim /etc/profile
- JAVA_HOME=/usr/java/jdk1.7.0_05
- PATH=$PATH:$JAVA_HOME/bin:$PATH
- export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE INPUTRC JAVA_HOME
- #. /etc/profile
- # printenv
- 有如下內容
- JAVA_HOME=/usr/java/jdk1.7.0_05
- # java -version //可以測試jdk是否生效
- java version "1.7.0_05"
- Java(TM) SE Runtime Environment (build 1.7.0_05-b05)
- Java HotSpot(TM) Client VM (build 23.1-b03, mixed mode, sharing)
- #tar xf apache-tomcat-7.0.29.tar.gz -C /usr/local
- # cd /usr/local
- # ln -sv apache-tomcat-7.0.29 tomcat
- # /usr/local/tomcat/bin/catalina.sh start 啓動
- 至此,兩臺服務器準備完畢
tomcat1和tomcat2上統一做如下配置
- tomcat1
- #vim /usr/local/tomcat/conf/server.xml
- 修改
- <Engine name="Catalina" defaultHost="localhost" jvmRoute="TomcatA">
- 演示效果,在TomcatA上某context中提供特定頁面
- #cd /usr/local/tomcat/webapps
- #mkdir -pv sess/WEB-INF/{lib,classes}
- #cd sess
- #vim index.jsp
- 添加如下內容
- <%@ page language="java" %>
- <html>
- <head><title>TomcatA</title></head>
- <body>
- <h1><font color="red">TomcatA </font></h1>
- <table align="centre" 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>
- #/usr/local/tomcat/conf/catalina.sh stop
- #/usr/local/tomcat/conf/catalina.sh stop
- tomcat2
- #vim /usr/local/tomcat/conf/server.xml
- 修改
- <Engine name="Catalina" defaultHost="localhost" jvmRoute="TomcatB">
- 演示效果,在TomcatB上某context中,提供特定頁面
- #cd /usr/local/tomcat/webapps
- #mkdir -pv sess/WEB-INF/{lib,classes}
- #cd sess
- #vim index.jsp
- 添加如下
- <%@ page language="java" %>
- <html>
- <head><title>TomcatB</title></head>
- <body>
- <h1><font color="blue">TomcatB </font></h1>
- <table align="centre" 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>
- # /usr/local/tomcat/bin/catalina.sh stop
- # /usr/local/tomcat/bin/catalina.sh start
二、整合apache和tomcat
2.1 基於mod_jk 實現負載均衡
- tomcat1:
- 修改/etc/httpd/extra/httpd-jk.conf爲如下內容:
- # Load the mod_jk
- LoadModule jk_module modules/mod_jk.so
- JkWorkersFile /etc/httpd/extra/workers.properties
- JkLogFile logs/mod_jk.log
- JkLogLevel debug
- JkMount /* lbcluster1
- JkMount /status stat1
- 保存退出
- (lbcluster1 這個名字是虛的,專門是爲了實現負載均衡的)
- 編輯/etc/httpd/extra/workers.properties,添加如下內容:
- worker.list=lbcluster1,stat1
- worker.TomcatA.port=8009
- worker.TomcatA.host=172.16.220.11
- worker.TomcatA.type=ajp13
- worker.TomcatA.lbfactor=1
- worker.TomcatB.port=8009
- worker.TomcatB.host=172.16.220.12
- worker.TomcatB.type=ajp13
- worker.TomcatB.lbfactor=1
- worker.lbcluster1.type=lb
- worker.lbcluster1.balance_workers=TomcatA,TomcatB
- worker.stat1.type=status
- worker.lbcluster1.sticky_session = 0
- #service httpd restart
測試:172.16.220.11/sess 刷新訪問,可以看到兩臺tomcat主機輪詢訪問,實現了負載均衡
問題依然存在,就是會話無法保持。接下來會解決這個問題
(把/etc/httpd/extra/workers.properties中的worker.lbcluster1.sticky_session 的值改爲1,發現請求總是定向到一臺tomcat服務器上)
2.2 基於mod_proxy實現負載均衡
- tomcat1:
- #vim /etc/httpd/httpd.conf
- Include /etc/httpd/extra/httpd-vhosts.conf
- #Include /etc/httpd/extra/httpd-jk.conf
- #vim /etc/httpd/extra/httpd-vhosts.conf
- 內容改爲:
- ProxyRequests Off
- ProxyPass / balancer://lbcluster1/ stickysession=jsessionid
- ProxyPa***everse / balancer://lbcluster1/
- <proxy balancer://lbcluster1>
- BalancerMember ajp://172.16.220.11:8009 loadfactor=10 route=TomcatA
- BalancerMember ajp://172.16.220.12:8009 loadfactor=10 route=TomcatB
- </proxy>
- <VirtualHost *:80>
- ServerAdmin [email protected]
- ServerName tomcat.magedu.com
- </VirtualHost>
- #service httpd restart
測試tomcat.magedu.com/sess 實現了負載均衡
但是會話依然無法保持(若配置worker.lbcluster1.sticky_session = 1 這裏的sticksession=jsessionid 訪問可以實現請求定向到一臺tomcat上)
四、tomcat基於session複製的集羣
- (DeltaManager 和BackupManager都可以實現)
- 在tomcat1主機上:
- #vim /usr/local/tomcat/conf/server.xml
- <Engine...>行下面添加如下內容:
- <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="228.50.10.1" bind="172.16.220.11" port="45564"
- frequency="500" dropTime="3000"/>
- <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
- address="172.16.220.11" 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=".*\.gif;.*\.js;.*\.jpg;.*\.htm;.*\.html;.*\.txt;"/>
- <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>
- #cp /usr/local/tomcat/conf/web.xml /usr/local/tomcat/webapps/sess/WEB-INF
- #vim /usr/local/tomcat/webapps/sess/WEB-INF/web.xml
- 在
- <web-app xmlns="http://java.sun.com/xml/ns/javaee"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
- http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
- version="3.0"> 後面添加如下
- <distributable/>
- #/usr/local/tomcat/bin/catalina.sh stop
- #/usr/local/tomcat/bin/catalina.sh start
- #service httpd restart
- tomcat2上的配置和tocmat1上的配置一樣,只不過是把tomcat1的地址改爲tomcat2的地址爲172.16.220.12,然後複製web.xml,重啓服務
訪問 tomcat.magedu.com/sess 效果是負載均衡,並且會話是保持的
此時前端也可以是mod_jk(把apache的配置文件中的虛擬主機取消,mod_jk啓用即可)
- 操作過程中遇到了不少問題,這裏分享一下:
- 1、第五步中啓動httpd時,啓動成功了,但是端口並沒有監聽,什麼原因?
- # tail /usr/local/apache/logs/error_log
- [Wed Aug 29 12:25:43.918479 2012] [proxy_balancer:emerg] [pid 25008:tid 3086427904] AH01177: Failed to lookup provider 'shm' for 'slotmem': is mod_slotmem_shm loaded?
- 編譯配置文件啓用這個模塊即可
- LoadModule slotmem_shm_module modules/mod_slotmem_shm.so
- 2、 使用mod_jk總是實現不了複製均衡,什麼問題?頁面訪問的一直是TomcatA,鬱悶啊
- 原因1:worker.lbcluster1.balance_workers = TomcatA,TomcatB 中 “TomcatA和TomcatB之間多了一個空格,導致TomcatA出不來
- 2:沒有加worker.lbcluster1.sticky_session = 0 ,導致無法負載均衡,添加上之後就OK了
- 3、做mod_proxy時遇到了錯誤
- 重啓httpd 時錯誤
- # service httpd restart
- Stopping httpd: [FAILED]
- Starting httpd: [ OK ]
- # tail /usr/local/apache/logs/error_log
- [proxy_balancer:emerg] [pid 4753:tid 3086935808] (22)Invalid argument: AH01186: worker slotmem_grab failed
- [Wed Aug 29 20:15:18.609721 2012] [:emerg] [pid 4753:tid 3086935808] AH00020: Configuration Failed, exiting
- 解決:在虛擬主機的配置文件中,第一次是把
- ProxyPass / balancer://lbcluster1/ stickysession=jsessionid
- ProxyPa***everse / balancer://lbcluster1/ 這兩項內容定義在了虛擬主機內部,出了錯誤
- 定義在全局位置就可以了
- 4、在實現session複製時,定義<distributable/>時,放在其他地方就不行,即便是放在
- <web-app xmlns="http://java.sun.com/xml/ns/javaee"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
- http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
- version="3.0"> 的前面就不行,一定要放在後面纔可以,可以是下面的任何一定地方,這是文件讀取時加載的順序