1 Reply Latest reply on Apr 10, 2007 6:30 PM by brian.stansberry

    HTTP Session Replication - immediate eviction

    lava_surfer
    lava_surfer Apr 10, 2007 5:45 PM

      I am prototyping HTTP session replication for fail over in a 2 node cluster. JBoss AS version 4.0.3SP1, JBoss Cache version 1.4.0.SP1, JGroups default as per AS, JDK 1.5.0_08.

      I have a simple two node cluster and a simple web application that writes a java.util.Date to the session each time the user clicks a submit button. The cluster appears to be working properly. Both nodes are present as verified via jmx-console in looking at the jboss service=My-Test-Partition-Tomcat and jboss.cache service=TomcatClusteringCache.

      I have a jmx-console open on each node and observe the contents of the cache via the TomcatClusteringCache MBean printDetails() method.

      I have enabled jboss cache DEBUG in log4j.xml.

      Here's what happens in my test case:

      1) Hit submit
      2) Both nodes 1 and 2 store the updated session data as seen via jmx.
      3) A second or two later, node 2 evicts the session data.
      4) Node 1 retains the session data as per the configured eviction policy.

      Perhaps I don't understand how the cache is supposed to work, but I am under the impression that each node would receive a copy of the session data as per the clustering configuration.

      Thanks in advance for your help.


      My tc5-cluster-service.xml is shown below.

      
<?xml version="1.0" encoding="UTF-8"?>

<!-- ===================================================================== -->
<!-- -->
<!-- Customized TreeCache Service Configuration for Tomcat 5 Clustering -->
<!-- -->
<!-- ===================================================================== -->

<server>

 <!-- ==================================================================== -->
 <!-- Defines TreeCache configuration -->
 <!-- ==================================================================== -->

 <mbean code="org.jboss.cache.TreeCache"
 name="jboss.cache:service=TomcatClusteringCache">

 <depends>jboss:service=Naming</depends>
 <depends>jboss:service=TransactionManager</depends>

 <!-- Configure the TransactionManager -->
 <attribute name="TransactionManagerLookupClass">org.jboss.cache.JBossTransactionManagerLookup</attribute>

 <!--
 Node locking scheme:
 OPTIMISTIC
 PESSIMISTIC (default)
 -->
 <attribute name="NodeLockingScheme">OPTIMISTIC</attribute>

 <!--
 Isolation level : SERIALIZABLE
 REPEATABLE_READ (default)
 READ_COMMITTED
 READ_UNCOMMITTED
 NONE
 -->
 <attribute name="IsolationLevel">REPEATABLE_READ</attribute>

 <!--
 Valid modes are LOCAL, REPL_ASYNC and REPL_SYNC
 -->
 <attribute name="CacheMode">REPL_ASYNC</attribute>

 <!-- Name of cluster. Needs to be the same for all clusters, in order
 to find each other
 -->
 <attribute name="ClusterName">${jboss.partition.name:DefaultPartition}-Tomcat</attribute>


 <!-- JGroups protocol stack properties. Can also be a URL,
 e.g. file:/home/bela/default.xml
 <attribute name="ClusterProperties"></attribute>
 -->

 <attribute name="ClusterConfig">
 <!--
 The default UDP stack:
 - If you have a multihomed machine, set the UDP protocol's bind_addr attribute to the
 appropriate NIC IP address, e.g bind_addr="192.168.0.2".
 - On Windows machines, because of the media sense feature being broken with multicast
 (even after disabling media sense) set the UDP protocol's loopback attribute to true
 -->
 <config>
 <UDP mcast_addr="${jboss.partition.udpGroup:228.1.2.3}" mcast_port="48866"
 ip_ttl="64" ip_mcast="true"
 mcast_send_buf_size="150000" mcast_recv_buf_size="80000"
 ucast_send_buf_size="150000" ucast_recv_buf_size="80000"
 loopback="false"/>
 <PING timeout="2000" num_initial_members="3"
 up_thread="false" down_thread="false"/>
 <MERGE2 min_interval="10000" max_interval="20000"/>
 <FD_SOCK/>
 <VERIFY_SUSPECT timeout="1500"
 up_thread="false" down_thread="false"/>
 <pbcast.NAKACK gc_lag="50" retransmit_timeout="600,1200,2400,4800"
 max_xmit_size="8192" up_thread="false" down_thread="false"/>
 <UNICAST timeout="600,1200,2400" window_size="100" min_threshold="10"
 down_thread="false"/>
 <pbcast.STABLE desired_avg_gossip="20000"
 up_thread="false" down_thread="false"/>
 <FRAG frag_size="8192"
 down_thread="false" up_thread="false"/>
 <pbcast.GMS join_timeout="5000" join_retry_timeout="2000"
 shun="true" print_local_addr="true"/>
 <pbcast.STATE_TRANSFER up_thread="true" down_thread="true"/>
 </config>

 </attribute>

 <!-- Max number of milliseconds to wait for a lock acquisition -->
 <attribute name="LockAcquisitionTimeout">15000</attribute>


 <attribute name="EvictionPolicyClass">org.jboss.cache.eviction.LRUPolicy</attribute>

 <attribute name="EvictionPolicyConfig">
 <config>
 <attribute name="wakeUpIntervalSeconds">30</attribute>
 <region name="/_default_">
 <attribute name="maxNodes">10000</attribute>
 <attribute name="timeToLiveSeconds">1800</attribute>
 <attribute name="maxAgeSeconds">1800</attribute>
 </region>
 </config>
 </attribute>

 </mbean>
</server>


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