HTTP Session Replication - immediate eviction
lava_surfer Apr 10, 2007 5:45 PMI 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>