javatomcatcluster-computingload-balancingsession-replication

session replication and clustering in tomcat?


I have configured the HttpServer2.2 to achieve the load balancing and the Clusteringfor my java application.

But the Load Balancing works fine and Clustering(session replication) not works .

My worker.properties in HttpServer will be ,

workers.java_home=C:/Program Files/Java/jdk1.6.0_25

#worker.list=worker1,worker2
worker.list=balancer

worker.worker1.port=8009
worker.worker1.host=localhost
worker.worker1.type=ajp13
worker.worker1.lbfactor=1

worker.worker2.port=8019
worker.worker2.host=192.168.100.84
worker.worker2.type=ajp13
worker.worker2.lbfactor=1

worker.balancer.type=lb
worker.balancer.balance_workers=worker1,worker2
worker.balancer.method=B
# Specifies whether requests with SESSION ID's 
# should be routed back to the same #Tomcat worker.
worker.balancer.sticky_session =True

and the httpd.conf will be,

<IfModule jk_module>

JkWorkersFile conf/workers.properties
JkLogFile logs/mod_jk.log
JkLogLevel info

JkMount /CustomerChat_V1.02.00 balancer
JkMount /CustomerChat_V1.02.00/* balance

</IfModule>

In my server.xml for Tomcat one,

<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="228.0.0.8"

            port="45564"
            frequency="500"
            dropTime="3000" />

        <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
              address="auto"
              port="4200"
              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;" />

     <Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer"
           tempDir="D:/cluster/temp/war-temp/"
           deployDir="D:/cluster/temp/war-deploy/"
           watchDir="D:/cluster/temp/war-listen/"
           watchEnabled="false" />

     <ClusterListener className="org.apache.catalina.ha.session.JvmRouteSessionIDBinderListener"/>

     <ClusterListener className="org.apache.catalina.ha.session.ClusterSessionListener"/>
</Cluster>

In my server.xml for Tomcat two,

       <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
                  address="192.168.0.1"
                  port="4100"
                  autoBind="100"
                  selectorTimeout="5000"
                  maxThreads="6" />

But Still having the problem.

When I shutdown the Tomcat one ,the new request will be automatically goes to the tomcat two. But the Tomcat two doesn't know about the current user state and his stored session object of the application.

hope our stack members will help me with this.

Good answers are definitely appreciated.


Solution

  • Some comments/suggestions

    EDIT:

    In your configuration you are mentioning

    worker.balancer.sticky_session =True
    

    this will make the HttpServer to send all the request to a tomcat where the session was created for first time (the session is stuck to that server hence the name sticky session). This defeats your purpose of session clustering. Please set this to false.