3 Replies Latest reply on Oct 12, 2007 9:33 AM by Pete Muir

    HOWTO: Seam 2.0 and <s:cache>

    sstrenn Newbie

      I found it difficult to get <s:cache> to work with seam 2.0 and JBoss 4.2. The documentation is currently a) spotty, b) out of date, and c) will generally send you into a black hole (due to a) and b)).

      I made my way out of the black hole, and here are the steps I used:

      a. Add the following to application.xml:

      b. In build.xml, add the following to the fileset dir=${lib.dir} element of the ear target:
      <include name="jgroups.jar" />
       <include name="jboss-cache-jdk50.jar" />

      c. Also in build.xml, add the following to the of the ear target:
      <include name="treecache.xml" />

      d. Save the following XML in a file called treecache.xml in your resources directory:

      <?xml version="1.0" encoding="UTF-8"?>
      <!-- ===================================================================== -->
      <!-- -->
      <!-- PojoCache Service Configuration -->
      <!-- -->
      <!-- ===================================================================== -->
       <!-- Used inside JBoss AS
       <classpath codebase="./lib" archives="jboss-cache.jar, jgroups.jar"/>
       <!-- ==================================================================== -->
       <!-- Defines configuration -->
       <!-- ==================================================================== -->
       <mbean code="org.jboss.cache.aop.PojoCache" name="jboss.cache:service=testPojoCache">
       <!-- Used inside JBoss AS -->
       Configure the TransactionManager
       <attribute name="TransactionManagerLookupClass">org.jboss.cache.DummyTransactionManagerLookup</attribute>
       Node locking scheme:
       PESSIMISTIC (default)
       <attribute name="NodeLockingScheme">PESSIMISTIC</attribute>
       Note that this attribute is IGNORED if your NodeLockingScheme above is OPTIMISTIC.
       Isolation level : SERIALIZABLE
       REPEATABLE_READ (default)
       <attribute name="IsolationLevel">REPEATABLE_READ</attribute>
       Valid modes are LOCAL
       <attribute name="CacheMode">LOCAL</attribute>
       <!-- Name of cluster. Needs to be the same for all clusters, in order
       to find each other
       <attribute name="ClusterName">Sample-Cluster</attribute>
       <!-- JGroups protocol stack properties. Can also be a URL,
       e.g. file:/home/bela/default.xml
       <attribute name="ClusterProperties"></attribute>
       <attribute name="ClusterConfig">
       <!-- UDP: if you have a multihomed machine,
       set the bind_addr attribute to the appropriate NIC IP address -->
       <!-- UDP: On Windows machines, because of the media sense feature
       being broken with multicast (even after disabling media sense)
       set the loopback attribute to true -->
       <UDP mcast_addr="" mcast_port="45577" 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 shun="true" up_thread="true" down_thread="true" />
       <VERIFY_SUSPECT timeout="1500" up_thread="false" down_thread="false" />
       <pbcast.NAKACK gc_lag="50" retransmit_timeout="600,1200,2400,4800" up_thread="false" down_thread="false" />
       <pbcast.STABLE desired_avg_gossip="20000" up_thread="false" down_thread="false" />
       <UNICAST timeout="600,1200,2400" window_size="100" min_threshold="10" 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="false" down_thread="false" />
       The max amount of time (in milliseconds) we wait until the
       initial state (ie. the contents of the cache) are retrieved from
       existing members in a clustered environment
       <attribute name="InitialStateRetrievalTimeout">20000</attribute>
       Number of milliseconds to wait until all responses for a
       synchronous call have been received.
       <attribute name="SyncReplTimeout">15000</attribute>
       <!-- Max number of milliseconds to wait for a lock acquisition -->
       <attribute name="LockAcquisitionTimeout">10000</attribute>
       <!-- Name of the eviction policy class. We have commented it off to disable eviction.
       <attribute name="EvictionPolicyClass">org.jboss.cache.aop.eviction.AopLRUPolicy</attribute>
       <!-- Specific eviction policy configurations. This is LRU -->
       <attribute name="EvictionPolicyConfig">
       <attribute name="wakeUpIntervalSeconds">5</attribute>
       <!-- Cache wide default -->
       <region name="/_default_">
       <attribute name="maxNodes">5000</attribute>
       <attribute name="timeToLiveSeconds">5</attribute>
       <region name="/aop">
       <attribute name="maxNodes">5</attribute>
       <attribute name="timeToLiveSeconds">4</attribute>
       <region name="/pojo">
       <attribute name="maxNodes">100</attribute>
       <attribute name="timeToLiveSeconds">4</attribute>
       <region name="/TopOrders">
       <attribute name="maxNodes">100</attribute>
       <attribute name="timeToLiveSeconds">0</attribute>
       <attribute name="maxAgeSeconds">5</attribute>

      e. The file is a modified version of JBossCache-1.4.1.SP4\etc\META-INF\pojocache-service.xml with the following changes:
      i. Commented out the classpath element.
      ii. Commented out the transaction manager
      iii. Added a new region called /TopOrders.

      f. To perform page fragment caching, enclose the fragment to cache in a <s:cache> tag with the key and region set. e.g.:
      <s:cache key="topOrders" region="/TopOrders" enabled="true"> ... </s:cache>

      This would cache the fragment in the /TopOrders region for 5 seconds.

      NOTE: The treecache.xml file provided above is configured for local cache mode with no transaction manager set. If that isn't applicable to your app (e.g. you have a clustered environment), you'll need to dig into the JBossCache documentation to learn more about its cache configuration settings.