Tomcat实现session保持案例
apache: tomcats
(1) apache:
mod_proxy
mod_proxy_http 实现代理
mod_proxy_balancer 实现负载均衡
tomcat:
http connector http连接器
(2) apache:
mod_proxy
mod_proxy_ajp ajp模块
mod_proxy_balancer
tomcat:
ajp connector ajp连接器
(3) apache:
mod_jk
tomcat:
ajp connector
方案一：使用nginx反代用户请求到tomcat：（实现负载均衡和session绑定）
配置hosts文件：
192.168.20.1 node1.lee.com node1
192.168.20.2 node2.lee.com node2
192.168.20.8 node4.lee.com node4
192.168.20.7 node3.lee.com node3
前端nginx配置实现负载均衡：
1.在http上下文定义upstream server
upstream tcsrvs {
ip_hash； 实现session绑定
server node1.lee.com:8080;
server node2.lee.com:8080;
}
2.在server段中调用：
location / {
root /usr/share/nginx/html;
}
location ~* \.(jsp|do)$ {
proxy_pass http://tcsrvs;
}
后端两个tomcat配置server.xml：
示例只给了第一台的配置，第二台的只需将所有node1改为node2即可
<Engine name="Catalina" defaultHost="node1.lee.com">
<Host name="node1.lee.com" appBase="/data/webapps/" unpackWARs="true" autoDeploy="true">
<Context path="" docBase="/data/webapps" reloadable="true">
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="/data/logs"
prefix="web1_access_log" suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" />
/data/webapps/index.jsp文件：
<%@ page language="java" %>
<%@ page import="java.util.*" %>
<html>
<head>
<title>JSP Test Page</title>
</head>
<body>
<% out.println("Hello, world."); %>
</body>
</html>
方案二：使用httpd反代用户请求到tomcat
前端httpd反代配置：
<proxy balancer://lbcluster1>
BalancerMember http://172.16.100.68:8080 loadfactor=10 route=TomcatA
BalancerMember http://172.16.100.69:8080 loadfactor=10 route=TomcatB
</proxy>
<VirtualHost *:80>
ServerName web1.lee.com
ProxyVia On
ProxyRequests Off
ProxyPreserveHost On
<Proxy *>
Order Deny,Allow
Allow from all
</Proxy>
ProxyPass /status !
ProxyPass / balancer://lbcluster1/
ProxyPassReverse / balancer://lbcluster1/
<Location />
Order Deny,Allow
Allow from all
</Location>
</VirtualHost>
后端tomcat主机配置：此处为node1主机，node2主机设置为 jvmRoute="TomcatB"，测试页也做相应替换
<Engine name="Catalina" defaultHost="node1.lee.com" jvmRoute="TomcatA"> #jvmRoute为了让前端httpd可以精确识别自己，使用jvmRoute作为标示
编辑测试页面：/data/webapps/index.jsp
<%@ page language="java" %>
<html>
<head><title>TomcatA</title></head>
<body>
<h1><font color="red">TomcatA.lee.com</font></h1>
<table align="centre" border="1">
<tr>
<td>Session ID</td> <% session.setAttribute("lee.com","lee.com"); %>
<td><%= session.getId() %></td>
</tr>
<tr>
<td>Created on</td>
<td><%= session.getCreationTime() %></td>
</tr>
</table>
</body>
</html>
测试：
发现即便调度到同一主机session也会变，更不用说不调度在同一主机
解决：修改这两行，使用session粘性功能
Header add Set-Cookie "ROUTEID=.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED
<proxy balancer://lbcluster1>
BalancerMember http://192.168.20.1:8080 loadfactor=10 route=TomcatA
BalancerMember http://192.168.20.2:8080 loadfactor=10 route=TomcatB
ProxySet stickysession=ROUTEID
</proxy>
测试后发现session绑定成功
使用ajp连接：只需要修改两行
#Header add Set-Cookie "ROUTEID=.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED
注释上面一行是因为使用ajp协议的话只需要ProxySet stickysession=ROUTEID一条语句即可绑定
<proxy balancer://lbcluster1>
BalancerMember ajp://172.16.100.68:8009 loadfactor=10 route=TomcatA
BalancerMember ajp://172.16.100.69:8009 loadfactor=10 route=TomcatB
ProxySet stickysession=ROUTEID
</proxy>
方案三：使用mod_jk作反向代理，使用mod_jk后端连接只能使用ajp协议
tar xf tomcat-connectors-1.2.40-src.tar.gz
cd tomcat-connectors-1.2.40-src/native
准备编译环境：
yum install httpd-devel gcc glibc-devel
yum groupinstall "Development tools"
mod_jk依赖于apxs
[root@node3 rpm]# which apxs
/usr/sbin/apxs
在native目录下：
./configure --with-apxs=/usr/sbin/apxs
装载mod_jk模块：在httpd.conf文件中：
LoadModule jk_module modules/mod_jk.so
查看是否装载成功：
[root@node3 conf]# httpd -M | grep jk
Syntax OK
jk_module (shared)
配置jk_module属性：httpd.conf中
JkWorkersFile /etc/httpd/conf.d/workers.properties
JkLogFile logs/mod_jk.log
JkLogLevel debug
JkMount /* TomcatA #此处的TomcatA必须与后端Tomcat的engine中定义哪个TomcatA的一致
JkMount /status/ stat1
创建/etc/httpd/conf.d/workers.properties
worker.list=TomcatA,stat1
worker.TomcatA.port=8009
worker.TomcatA.host=192.168.20.1
worker.TomcatA.type=ajp13
worker.TomcatA.lbfactor=1
worker.stat1.type = status
访问mod_jk自带的status页面：此页面也有管理功能
改为负载均衡：并且会话绑定功能
修改httpd.conf：
JkWorkersFile /etc/httpd/conf.d/workers.properties
JkLogFile logs/mod_jk.log
JkLogLevel debug
JkMount /* lbcluster1
JkMount /jkstatus/ stat1
修改/etc/httpd/conf.d/workers.properties
worker.list = lbcluster1,stat1
worker.TomcatA.type = ajp13
worker.TomcatA.host = 192.168.20.1
worker.TomcatA.port = 8009
worker.TomcatA.lbfactor = 5
worker.TomcatB.type = ajp13
worker.TomcatB.host = 192.168.20.2
worker.TomcatB.port = 8009
worker.TomcatB.lbfactor = 5
worker.lbcluster1.type = lb
worker.lbcluster1.sticky_session = 1
worker.lbcluster1.balance_workers = TomcatA, TomcatB
worker.stat1.type = status
测试成功
介绍：proxy-balancer-manager模块页面的使用
<proxy balancer://lbcluster1>
BalancerMember http://192.168.20.1:8080 loadfactor=10 route=TomcatA
BalancerMember http://192.168.20.2:8080 loadfactor=10 route=TomcatB
ProxySet stickysession=ROUTEID
</proxy>
<VirtualHost *:80>
ServerName web1.lee.com
ProxyVia On
ProxyRequests Off
ProxyPreserveHost On
<Location /balancer-manager>
SetHandler balancer-manager
ProxyPass !
Order Deny,Allow
Allow from all
</Location>
<Proxy *>
Order Deny,Allow
Allow from all
</Proxy>
ProxyPass /status !
ProxyPass / balancer://lbcluster1/
ProxyPassReverse / balancer://lbcluster1/
<Location />
Order Deny,Allow
Allow from all
</Location>
</VirtualHost>
测试：
delta-manager实现会话复制集群实现
在server.xml中Host上下文中添加：
<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="228.0.1.7"
port="45564"
frequency="500"
dropTime="3000"/>
<Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
address="192.168.20.1" #node2改成192.168.20.2
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.ClusterSessionListener"/>
</Cluster>
配置我们的特定应用程序调用上面的cluster功能
[root@node1 conf]# cp web.xml /data/webapps/WEB-INF/
[root@node1 conf]# vim /data/webapps/WEB-INF/web.xml
添加<distributable/>
[root@node1 conf]# scp /data/webapps/WEB-INF/web.xml node2:/data/webapps/WEB-INF/
web.xml 100% 163KB 162.7KB/s 00:00
查看日志，发现集群中加入了主机：
tail -100 /usr/local/tomcat/logs/catalina.out
01-Nov-2015 00:09:04.215 INFO [Membership-MemberAdded.] org.apache.catalina.ha.tcp.SimpleTcpCluster.memberAdded Replication member added:org.apache.catalina.tribes.membership.MemberImpl[tcp://{192, 168, 20, 2}:4000,{192, 168, 20, 2},4000, alive=1036, securePort=-1, UDP Port=-1, id={-40 -58 -73 -47 -114 -18 76 74 -81 -66 125 -30 -36 -78 -87 -23 }, payload={}, command={}, domain={}, ]
测试发现尽管负载均衡切换了主机，但是session不会改变
同理，使用Mod_jk和ajp连接后端也成功，使用nginx做反代也行，这里就不缀余了
使用msm实现session服务器实现：
借助于memcached：
yum install memcached
[root@node3 ~]# cat /etc/sysconfig/memcached
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="64"
OPTIONS=""
提供四个java类库：
[root@node1 msm-1.8.3]# ls
memcached-session-manager-1.8.3.jar msm-javolution-serializer-1.8.3.jar
memcached-session-manager-tc8-1.8.3.jar spymemcached-2.10.2.jar
javolution-5.5.1.jar
放置于两台tomcat服务器的/usr/local/tomcat/lib目录下：
[root@node1 ~]# scp -r msm-1.8.3/ node2:/usr/local/tomcat/lib
The authenticity of host 'node2 (192.168.20.2)' can't be established.
RSA key fingerprint is d5:69:d0:fc:ce:90:14:14:6d:4c:52:82:53:a5:ed:0b.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'node2,192.168.20.2' (RSA) to the list of known hosts.
root@node2's password:
spymemcached-2.10.2.jar 100% 429KB 428.8KB/s 00:00
memcached-session-manager-tc8-1.8.3.jar 100% 10KB 10.2KB/s 00:00
msm-javolution-serializer-1.8.3.jar 100% 69KB 69.4KB/s 00:00
memcached-session-manager-1.8.3.jar 100% 144KB 143.6KB/s 00:00
javolution-5.5.1.jar 100% 144KB 143.6KB/s 00:00
编辑server.xml文件Host上下文中定义context
<Context path="" docBase="/data/webapps" reloadable="true">
<Manager className="de.javakaffee.web.msm.MemcachedBackupSessionManager"
memcachedNodes="n1:192.168.20.7:11211,n2:192.168.20.8:11211"
failoverNodes="n1"
requestUriIgnorePattern=".*\.(ico|png|gif|jpg|css|js)$"
transcoderFactoryClass="de.javakaffee.web.msm.serializer.javolution.JavolutionTranscoderFactory"
/>
<Valve className="org.apache.catalina.valves.RemoteAddrValve"
deny="172\.16\.100\.100"/>
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="/data/logs"
prefix="web1_access_log" suffix=".txt"
pattern="%h %l %u %t "%r" %s %b" />
</Context>
更多Tomcat相关教程见以下内容：