HOWTO: Seam 2.0 and <s:cache>
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 The documentation is currently a) spotty, b) out of date, and c) will generally send you into a black hole (due to a) and b)).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:
<module> <java>jboss-cache-jdk50.jar</java> </module> <module> <java>jgroups.jar</java> </module>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 --> <!-- --> <!-- ===================================================================== --> <server> <!-- 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 --> <depends>jboss:service=Naming</depends> <depends>jboss:service=TransactionManager</depends> <!-- Configure the TransactionManager <attribute name="TransactionManagerLookupClass">org.jboss.cache.DummyTransactionManagerLookup</attribute> --> <!-- Node locking scheme: OPTIMISTIC 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) READ_COMMITTED READ_UNCOMMITTED NONE --> <attribute name="IsolationLevel">REPEATABLE_READ</attribute> <!-- Valid modes are LOCAL REPL_ASYNC REPL_SYNC INVALIDATION_ASYNC INVALIDATION_SYNC --> <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"> <config> <!-- 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="228.1.2.5" 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" /> </config> </attribute> <!-- 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"> <config> <attribute name="wakeUpIntervalSeconds">5</attribute> <!-- Cache wide default --> <region name="/_default_"> <attribute name="maxNodes">5000</attribute> <attribute name="timeToLiveSeconds">5</attribute> </region> <region name="/aop"> <attribute name="maxNodes">5</attribute> <attribute name="timeToLiveSeconds">4</attribute> </region> <region name="/pojo"> <attribute name="maxNodes">100</attribute> <attribute name="timeToLiveSeconds">4</attribute> </region> <region name="/TopOrders"> <attribute name="maxNodes">100</attribute> <attribute name="timeToLiveSeconds">0</attribute> <attribute name="maxAgeSeconds">5</attribute> </region> </config> </attribute> </mbean> </server>
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.
Stephen
