apache+tomcat 负载均衡+session绑定 配置集群环境
其中负载均衡由Apache2.2.4担任 内部服务器为Tomcat 6
实验中本机运行1个Apache与两个Tomcat 6
当然 目前只知道怎么配置 能大概理解部分配置文件属性 具体配置文件的所有含义还不明白……
安装好Apache与Tomcat后开始配置
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1 下载Tomcat Connector(jk.1.2.6)
Tomcat Connector下载地址：http://archive.apache.org/dist/tomcat/tomcat-connectors/jk/binaries/win32/jk-1.2.26/
此处注意一定要下载与Apache版本匹配的jk。jk文件名后半部分名称反应Apache的版本，如：mod_jk-1.2.26-httpd-2.2.4.so其匹配的Apache为2.2.4，与本次安装的Apache版本一致。
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2 Apache配置
?????? 把下载的 mod_jk-1.2.28-httpd-2.2.3.so 改名为 mod_jk2.so 放到apache的modules目录下（不改名不行么？不知道为什么我的没改名，就出问题了，当然我的配置文件中也是mod_jk-1.2.28-httpd-2.2.3.so 但是就是不知道为什么会有问题），修改apache的conf目录下的httpd.conf，在文件最后加入一行include conf\mod_jk2.conf，在conf目录下创建mod_jk2.conf文件，内容如下：
#?Load?mod_jk2?module ??
LoadModule?jk_module?modules/mod_jk2.so???
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#?Where?to?find?workers.properties ??
JkWorkersFile?conf/workers.properties????
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#?Where?to?put?jk?logs ??
JkLogFile?logs/mod_jk2.log ??
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#?Set?the?jk?log?level?[debug/error/info] ??
JkLogLevel?info ??
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#?Select?the?log?format ??
JkLogStampFormat?"[%a?%b?%d?%H:%M:%S?%Y]?"??
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#?JkOptions?indicate?to?send?SSL?KEY?SIZE, ??
JkOptions?+ForwardKeySize?+ForwardURICompat?-ForwardDirectories ??
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#?JkRequestLogFormat?set?the?request?format ??
JkRequestLogFormat?"%w?%V?%T"??
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#?Send?JSPs?for?context?/?to?worker?named?loadBalancer ??
JkMount?/*.jsp?loadBalancer??
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2??jk2配置
???jk2的配置全在一个配置文件中，文件名为workers.properties，和apache 的httpd.conf放在同一个目录下。以下是这个文件的内容：
#??
# workers.properties??
#??
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# list the workers by name??
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worker.list=tomcat1, tomcat2, loadBalancer??
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# ------------------------??
# First tomcat server??
# ------------------------??
worker.tomcat1.port=8009?
worker.tomcat1.host=192.168.2.203?
worker.tomcat1.type=ajp13??
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# Specify the size of the open connection cache.??
#worker.tomcat1.cachesize??
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#??
# Specifies the load balance factor when used with??
# a load balancing worker.??
# Note:??
# ----> lbfactor must be > 0?
# ----> Low lbfactor means less work done by the worker.??
#分发权重 值越大负载越大 测试时可以通过控制分发权值定负载顺序 测试session绑定是否成功
worker.tomcat1.lbfactor=9?
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# ------------------------??
# Second tomcat server??
# ------------------------??
worker.tomcat2.port=9009?
worker.tomcat2.host=192.168.2.203
worker.tomcat2.type=ajp13??
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# Specify the size of the open connection cache.??
#worker.tomcat2.cachesize??
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#??
# Specifies the load balance factor when used with??
# a load balancing worker.??
# Note:??
# ----> lbfactor must be > 0?
# ----> Low lbfactor means less work done by the worker.??
worker.tomcat2.lbfactor=100?
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# ------------------------??
# Load Balancer worker??
# ------------------------??
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#??
# The loadbalancer (type lb) worker performs weighted round-robin??
# load balancing with sticky sessions.??
# Note:??
# ----> If a worker dies, the load balancer will check its state??
# once in a while. Until then all work is redirected to peer??
# worker.??
worker.loadBalancer.type=lb??
worker.loadBalancer.balanced_workers=tomcat1, tomcat2??
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#??
# END workers.properties??
#?
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3 配置tomcat（绑定session）
Tomcat配置文件Service.xml主要注意两个地方，一个是Engine节点需要增加节点标识jvmRoute，一个是将原本注释掉的Session复制节点改为有效。具体如下：
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<!-- Define the top level container in our container hierarchy -->
<!--jvmRoute在各个Tomcat配置中不能重复且要与worker.properties文件中的名称一致-->
<Engine name="Catalina" defaultHost=" saas " ?jvmRoute=" tomcat1">
<!—每个Tomcat的Hostname必须一样-->
<Host name="saas" appBase="webapps "
?????? unpackWARs="true" autoDeploy="true"
?????? xmlValidation="false" xmlNamespaceAware="false">
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到此为止，负载均衡配置完毕
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这里省略N多注释
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将下面的注释变去掉（session复制需做以下操作）
<!--
??????? <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
????
????????????? <Valve className="org.apache.catalina.valves.RequestDumperValve"/>
-->
增加：
<Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"?
???????????????? channelSendOptions="8">??
????????? <Manager className="org.apache.catalina.ha.session.DeltaManager"?
?????????????????? expireSessionsOnShutdown="false"?
?????????????????? notifyListenersOnReplication="true"/>??
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????????? <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"/>??
??????????? <!-- timeout="60000"-->??
??????????? <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"/>??
???????? <Interceptor className="org.apache.catalina.tribes.group.interceptors.ThroughputInterceptor"/>??
????????? </Channel>??
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????????? <Valve className="org.apache.catalina.ha.tcp.ReplicationValve"?
???????????????? filter=""/>??
????????? <Valve className="org.apache.catalina.ha.session.JvmRouteBinderValve"/>??
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????????? <Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer"?
??????????????????? tempDir="/tmp/war-temp/"?
??????????????????? deployDir="/tmp/war-deploy/"?
??????????????????? watchDir="/tmp/war-listen/"?
??????????????????? watchEnabled="false"/>??
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????????? <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/>??
????????? <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/>??
??????? </Cluster>
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<!—Host节点增加一下内容表示站点根路径-->
??????? <Context path="/sc" docBase="." privileged="true"/>
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我们分别将两个Tomcat配置文件中的jvmRoute设置为tomcat1、tomcat2，Server节点 端口分别配置为8005和9005， Connector节点端口分别配置为8080和9090，AJPConnector端口分别配置为8009和9009，Connector端口配置参照单主机多站点场景。请注意两个Tomcat配置文件Host节点的域名配置必须一样，Server.xml中的jvmRoute名称必须和worker.properties中的tomcat实例名称一致，不然无法实现session_stricky。
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Host节点的域名配置方法：修改C:\WINDOWS\system32\drivers\etc 下的 hosts文件增加一行
127.0.0.1?????? saas
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?实现session 复制 需要在web.xml 中加上<distributable/>
<?xml version="1.0" encoding="ISO-8859-1"?>
省略N多代码。。。。。。
??? <welcome-file-list>
??????? <welcome-file>index.html</welcome-file>
??????? <welcome-file>index.htm</welcome-file>
??????? <welcome-file>index.jsp</welcome-file>
??? </welcome-file-list>
<distributable/>
</web-app>
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