Session CentOS上的Tomcat群集无法共享会话？

我在CentOS 7上有一个由三个Tomcat组成的集群，但它们不能共享会话。当我打开第二页时，第一页的会话会立即更新。 其中一个server.xml，我指的是官方示例：

<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="228.0.0.4"
       port="45564"
       frequency="500"
       dropTime="3000"/>
  <Receiver className="org.apache.catalina.tribes.transport.nio.NioReceiver"
       address="127.0.0.1"
       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.MessageDispatchInterceptor"/>
</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>

最后，他们不能共享会话