All properties of the cache are configured via setters and can be retrieved via getters. This can be done either manually, or via the PropertyConfigurator and an XML file.
A sample XML configuration file is shown below:
<?xml version="1.0" encoding="UTF-8" ?>
<server>
<classpath codebase="./lib" archives="jboss-cache.jar, jgroups.jar" />
<!-- ==================================================================== -->
<!-- Defines TreeCache configuration -->
<!-- ==================================================================== -->
<mbean code="org.jboss.cache.TreeCache" name="jboss.cache:service=TreeCache">
<depends>jboss:service=Naming</depends>
<depends>jboss:service=TransactionManager</depends>
<!-- Configure the TransactionManager -->
<attribute name="TransactionManagerLookupClass">org.jboss.cache.DummyTransactionManagerLookup</attribute>
<!--
Node locking scheme :
PESSIMISTIC (default)
OPTIMISTIC
-->
<attribute name="NodeLockingScheme">PESSIMISTIC</attribute>
<!--
Node locking isolation level :
SERIALIZABLE
REPEATABLE_READ (default)
READ_COMMITTED
READ_UNCOMMITTED
NONE
(ignored if NodeLockingScheme is OPTIMISTIC)
-->
<attribute name="IsolationLevel">REPEATABLE_READ</attribute>
<!-- Lock parent before doing node additions/removes -->
<attribute name="LockParentForChildInsertRemove">true</attribute>
<!-- Valid modes are LOCAL
REPL_ASYNC
REPL_SYNC
INVALIDATION_ASYNC
INVALIDATION_SYNC
-->
<attribute name="CacheMode">LOCAL</attribute>
<!-- Whether each interceptor should have an mbean
registered to capture and display its statistics. -->
<attribute name="UseInterceptorMbeans">true</attribute>
<!-- Name of cluster. Needs to be the same for all TreeCache nodes in a
cluster, in order to find each other -->
<attribute name="ClusterName">JBoss-Cache-Cluster</attribute>
<!-- Uncomment next three statements to enable JGroups multiplexer.
This configuration is dependent on the JGroups multiplexer being
registered in an MBean server such as JBossAS. -->
<!--
<depends>jgroups.mux:name=Multiplexer</depends>
<attribute name="MultiplexerService">jgroups.mux:name=Multiplexer</attribute>
<attribute name="MultiplexerStack">udp</attribute>
-->
<!-- JGroups protocol stack properties. ClusterConfig isn't used if the
multiplexer is enabled and successfully initialized. -->
<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="228.1.2.3" mcast_port="45566" 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" max_xmit_size="8192" retransmit_timeout="600,1200,2400,4800" 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="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">5000</attribute>
<!-- Number of milliseconds to wait until all responses for a
synchronous call have been received.
-->
<attribute name="SyncReplTimeout">10000</attribute>
<!-- Max number of milliseconds to wait for a lock acquisition -->
<attribute name="LockAcquisitionTimeout">15000</attribute>
<!-- Name of the eviction policy class. -->
<attribute name="EvictionPolicyClass">org.jboss.cache.eviction.LRUPolicy</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">1000</attribute>
<!-- Maximum time an object is kept in cache regardless of idle time -->
<attribute name="maxAgeSeconds">120</attribute>
</region>
<region name="/org/jboss/data">
<attribute name="maxNodes">5000</attribute>
<attribute name="timeToLiveSeconds">1000</attribute>
</region>
<region name="/org/jboss/test/data">
<attribute name="maxNodes">5</attribute>
<attribute name="timeToLiveSeconds">4</attribute>
</region>
</config>
</attribute>
<!-- New 1.3.x cache loader config block -->
<attribute name="CacheLoaderConfiguration">
<config>
<!-- if passivation is true, only the first cache loader is used; the rest are ignored -->
<passivation>false</passivation>
<preload>/a/b, /allTempObjects, /some/specific/fqn</preload>
<shared>false</shared>
<!-- we can now have multiple cache loaders, which get chained -->
<cacheloader>
<class>org.jboss.cache.loader.FileCacheLoader</class>
<!-- same as the old CacheLoaderConfig attribute -->
<properties>
location=/tmp/myFileStore
</properties>
<!-- whether the cache loader writes are asynchronous -->
<async>false</async>
<!-- only one cache loader in the chain may set fetchPersistentState to true.
An exception is thrown if more than one cache loader sets this to true. -->
<fetchPersistentState>true</fetchPersistentState>
<!-- determines whether this cache loader ignores writes - defaults to false. -->
<ignoreModifications>false</ignoreModifications>
<!-- if set to true, purges the contents of this cache loader when the cache starts up.
Defaults to false. -->
<purgeOnStartup>false</purgeOnStartup>
</cacheloader>
<cacheloader>
<class>org.jboss.cache.loader.JDBCCacheLoader</class>
<!-- same as the old CacheLoaderConfig attribute -->
<properties>
cache.jdbc.driver=com.mysql.jdbc.Driver
cache.jdbc.url=jdbc:mysql://localhost:3306/jbossdb
cache.jdbc.user=root
cache.jdbc.password=
</properties>
<!-- whether the cache loader writes are asynchronous -->
<async>true</async>
<!-- only one cache loader in the chain may set fetchPersistentState to true.
An exception is thrown if more than one cache loader sets this to true. -->
<fetchPersistentState>false</fetchPersistentState>
<!-- determines whether this cache loader ignores writes - defaults to false. -->
<ignoreModifications>true</ignoreModifications>
<!-- if set to true, purges the contents of this cache loader when the cache starts up.
Defaults to false. -->
<purgeOnStartup>false</purgeOnStartup>
</cacheloader>
</config>
</attribute>
</mbean>
</server> The PropertyConfigurator.configure() method needs to have as argument a filename which is located on the classpath; it will use be used to configure JBoss Cache from the properties defined in it. Note that this configuration file is used to configure JBoss Cache both as a standalone cache, and as an MBean if run inside the JBoss container.[8]
A list of definitions of each of the XML attributes used above:
Name | Description |
BuddyReplicationConfig | An XML element that contains detailed buddy replication configuration. See section above on Buddy Replication. |
CacheLoaderConfiguration | An XML element that contains detailed cache loader configuration. See section above on Cache Loaders. |
CacheMode | LOCAL, REPL_SYNC, REPL_ASYNC, INVALIDATION_SYNC or INVALIDATION_ASYNC |
ClusterConfig | The configuration of the underlying JGroups stack. Ignored if MultiplexerService and MultiplexerStack are used. See the various *-service.xml files in the source distribution etc/META-INF folder for examples. See the JGroups documentation or the JGroups wiki page for more information. |
ClusterName | Name of cluster. Needs to be the same for all nodes in a cluster in order for them to communicate with each other. |
EvictionPolicyClass | The name of a class implementing EvictionPolicy. Deprecated; it is preferable to configure the eviction policy class as part of the EvictionPolicyConfig. |
EvictionPolicyConfig | Configuration parameter for the specified eviction policy. Note that the content is provider specific. |
FetchInMemoryState (renamed from FetchStateOnStartup) | Whether or not to acquire the initial in-memory state from existing members. Allows for hot/cold caches (true/false). Also see the fetchPersistentState element in CacheLoaderConfiguration. |
InactiveOnStartup | Whether or not the entire tree is inactive upon startup, only responding to replication messages after activateRegion() is called to activate one or more parts of the tree. If true, property FetchInMemoryState is ignored. This property should only be set to true if UseRegionBasedMarshalling is also true. |
InitialStateRetrievalTimeout | Time in milliseconds to wait for initial state retrieval. This should be longer than LockAcquisitionTimeout as the node providing state may need to wait that long to acquire necessary read locks on the cache. |
IsolationLevel | Node locking isolation level : SERIALIZABLE, REPEATABLE_READ (default), READ_COMMITTED, READ_UNCOMMITTED, and NONE. Note that this is ignored if NodeLockingScheme is OPTIMISTIC. Case doesn't matter. See documentation on Transactions and Concurrency for more details. |
LockAcquisitionTimeout | Time in milliseconds to wait for a lock to be acquired. If a lock cannot be acquired an exception will be thrown. |
LockParentForChildInsertRemove | Controls whether inserting or removing a node requires a write lock on the node's parent (when pessimistic locking is used). The default value is false. |
MultiplexerService | The JMX object name of the service that defines the JGroups multiplexer. In JBoss AS 5 this service is normally defined in the jgroups-multiplexer.sar. If this attribute is defined, the cache will look up the multiplexer service in JMX and will use it to obtain a multiplexed JGroups channel. The configuration of the channel will be that associated with MultiplexerStack. The ClusterConfig attribute will be ignored. |
MultiplexerStack | The name of the JGroups stack to be used with the TreeCache cluster. Stacks are defined in the configuration of the external MultiplexerService discussed above. In JBoss AS 5 this is normally done in the jgroups-multiplexer.sar\META-INF\multiplexer-stacks.xml file. The default stack is udp. This attribute is used in conjunction with MultiplexerService. |
NodeLockingScheme | May be PESSIMISTIC (default) or OPTIMISTIC. See documentation on Transactions and Concurrency for more details. |
ReplicationVersion | Tells the cache to serialize cluster traffic in a format consistent with that used by the given release of JBoss Cache. Different JBoss Cache versions use different wire formats; setting this attribute tells a cache from a later release to serialize data using the format from an earlier release. This allows caches from different releases to interoperate. For example, a 1.2.4.SP2 cache could have this value set to "1.2.3", allowing it to interoperate with a 1.2.3 cache. Valid values are a dot-separated release number, with any SP qualifer also separated by a dot, e.g. "1.2.3" or "1.2.4.SP2". |
ReplQueueInterval | Time in milliseconds for elements from the replication queue to be replicated. |
ReplQueueMaxElements | Max number of elements in the replication queue until replication kicks in. |
SyncCommitPhase | This option is used to control the behaviour of the commit part of a 2-phase commit protocol, when using REPL_SYNC (does not apply to other cache modes). By default this is set to false. There is a performance penalty to enabling this, especially when running in a large cluster, but the upsides are greater cluster-wide data integrity. See the chapter on Clustered Caches for more information on this. |
SyncReplTimeout | For synchronous replication: time in milliseconds to wait until replication acks have been received from all nodes in the cluster. |
SyncRollbackPhase | This option is used to control the behaviour of the rollback part of a 2-phase commit protocol, when using REPL_SYNC (does not apply to other cache modes). By default this is set to false. There is a performance penalty to enabling this, especially when running in a large cluster, but the upsides are greater cluster-wide data integrity. See the chapter on Clustered Caches for more information on this. |
TransactionManagerLookupClass | The fully qualified name of a class implementing TransactionManagerLookup. Default is JBossTransactionManagerLookup. There is also an option of DummyTransactionManagerLookup for example. |
UseInterceptorMbeans | Specifies whether each interceptor should have an associated mbean registered. Interceptor mbeans are used to capture statistics and display them in JMX. This setting enables or disables all such interceptor mbeans. Default value is true. |
UseRegionBasedMarshalling | When unmarshalling replicated data, this option specifies whether or not to use different classloaders (for different cache regions). This defaults to false if unspecified. |
UseReplQueue | For asynchronous replication: whether or not to use a replication queue (true/false). |
LockParentForChildInsertRemove | When used with pessimistic locking and IsolationLevel of REPEATABLE_READ, this parameter specifies whether parent nodes need to be locked for writing when adding or removing child nodes. This prevents phantom reads, providing "stronger-than-repeatable-read" data integrity. This defaults to false and is ignored if used with optimistic locking or other isolation levels. |
As of JBoss Cache 1.3.0, a new API has been introduced, to allow you to override certain behaviour of the cache on a per invocation basis. This involves creating an instance of org.jboss.cache.config.Option, setting the options you wish to override on the Option object and passing it in as a parameter to overloaded versions of get(), put() and remove(). See the javadocs on the Option class for details on these options.