D-Net

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

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:noNamespaceSchemaLocation="ehcache.xsd" >

    <diskStore path="java.io.tmpdir"/>

    <!--

    Cache configuration

    ===================

    The following attributes are required.

    name:

    Sets the name of the cache. This is used to identify the cache. It must be unique.

    maxElementsInMemory:

    Sets the maximum number of objects that will be created in memory

	maxElementsOnDisk:

    Sets the maximum number of objects that will be maintained in the DiskStore

	The default value is zero, meaning unlimited.

    eternal:

    Sets whether elements are eternal. If eternal,  timeouts are ignored and the

    element is never expired.

    overflowToDisk:

    Sets whether elements can overflow to disk when the memory store

    has reached the maxInMemory limit.

    The following attributes and elements are optional.

    timeToIdleSeconds:

    Sets the time to idle for an element before it expires.

    i.e. The maximum amount of time between accesses before an element expires

    Is only used if the element is not eternal.

    Optional attribute. A value of 0 means that an Element can idle for infinity.

    The default value is 0.

    timeToLiveSeconds:

    Sets the time to live for an element before it expires.

    i.e. The maximum time between creation time and when an element expires.

    Is only used if the element is not eternal.

    Optional attribute. A value of 0 means that and Element can live for infinity.

    The default value is 0.

    diskPersistent:

    Whether the disk store persists between restarts of the Virtual Machine.

    The default value is false.

    diskExpiryThreadIntervalSeconds:

    The number of seconds between runs of the disk expiry thread. The default value

    is 120 seconds.

    diskSpoolBufferSizeMB:

    This is the size to allocate the DiskStore for a spool buffer. Writes are made

    to this area and then asynchronously written to disk. The default size is 30MB.

    Each spool buffer is used only by its cache. If you get OutOfMemory errors consider

    lowering this value. To improve DiskStore performance consider increasing it. Trace level

    logging in the DiskStore will show if put back ups are occurring. 

    memoryStoreEvictionPolicy:

    Policy would be enforced upon reaching the maxElementsInMemory limit. Default

    policy is Least Recently Used (specified as LRU). Other policies available -

    First In First Out (specified as FIFO) and Less Frequently Used

    (specified as LFU)

    Cache elements can also contain sub elements which take the same format of a factory class

    and properties. Defined sub-elements are:

    * cacheEventListenerFactory - Enables registration of listeners for cache events, such as

      put, remove, update, and expire.

    * bootstrapCacheLoaderFactory - Specifies a BootstrapCacheLoader, which is called by a

      cache on initialisation to prepopulate itself.

    * cacheExtensionFactory - Specifies a CacheExtension, a generic mechansim to tie a class

      which holds a reference to a cache to the cache lifecycle.

    * cacheExceptionHandlerFactory - Specifies a CacheExceptionHandler, which is called when

      cache exceptions occur.

    * cacheLoaderFactory - Specifies a CacheLoader, which can be used both asynchronously and

      synchronously to load objects into a cache. More than one cacheLoaderFactory element

      can be added, in which case the loaders form a chain which are executed in order. If a

      loader returns null, the next in chain is called.

    RMI Cache Replication

    +++++++++++++++++++++

    Each cache that will be distributed needs to set a cache event listener which replicates

    messages to the other CacheManager peers. For the built-in RMI implementation this is done

    by adding a cacheEventListenerFactory element of type RMICacheReplicatorFactory to each

    distributed cache's configuration as per the following example:

    <cacheEventListenerFactory class="net.sf.ehcache.distribution.RMICacheReplicatorFactory"

         properties="replicateAsynchronously=true,

         replicatePuts=true,

         replicatePutsViaCopy=false,

         replicateUpdates=true,

         replicateUpdatesViaCopy=true,

         replicateRemovals=true

         asynchronousReplicationIntervalMillis=<number of milliseconds"

         propertySeparator="," />

    The RMICacheReplicatorFactory recognises the following properties:

    * replicatePuts=true|false - whether new elements placed in a cache are

      replicated to others. Defaults to true.

    * replicatePutsViaCopy=true|false - whether the new elements are

      copied to other caches (true), or whether a remove message is sent. Defaults to true.  

    * replicateUpdates=true|false - whether new elements which override an

      element already existing with the same key are replicated. Defaults to true.

    * replicateRemovals=true - whether element removals are replicated. Defaults to true.

    * replicateAsynchronously=true | false - whether replications are

      asynchronous (true) or synchronous (false). Defaults to true.

    * replicateUpdatesViaCopy=true | false - whether the new elements are

      copied to other caches (true), or whether a remove message is sent. Defaults to true.

    * asynchronousReplicationIntervalMillis=<number of milliseconds> - The asynchronous

      replicator runs at a set interval of milliseconds. The default is 1000. The minimum

      is 10. This property is only applicable if replicateAsynchronously=true

    JGroups Replication

    +++++++++++++++++++

	For the Jgroups replication this is done with:

	<cacheEventListenerFactory class="net.sf.ehcache.distribution.jgroups.JGroupsCacheReplicatorFactory"

                            properties="replicateAsynchronously=true, replicatePuts=true,

 							replicateUpdates=true, replicateUpdatesViaCopy=false,

 							replicateRemovals=true,asynchronousReplicationIntervalMillis=1000"/>

    This listener supports the same properties as the RMICacheReplicationFactory.

    JMS Replication

    +++++++++++++++

	For JMS-based replication this is done with:

	<cacheEventListenerFactory

          class="net.sf.ehcache.distribution.jms.JMSCacheReplicatorFactory"

          properties="replicateAsynchronously=true,

                       replicatePuts=true,

                       replicateUpdates=true,

                       replicateUpdatesViaCopy=true,

                       replicateRemovals=true,

                       asynchronousReplicationIntervalMillis=1000"

           propertySeparator=","/>

    This listener supports the same properties as the RMICacheReplicationFactory.

    Cluster Bootstrapping

    +++++++++++++++++++++

    (RMI clusters only)

    The RMIBootstrapCacheLoader bootstraps caches in clusters where RMICacheReplicators are

    used. It is configured as per the following example:

    <bootstrapCacheLoaderFactory

        class="net.sf.ehcache.distribution.RMIBootstrapCacheLoaderFactory"

        properties="bootstrapAsynchronously=true, maximumChunkSizeBytes=5000000"

        propertySeparator="," />

    The RMIBootstrapCacheLoaderFactory recognises the following optional properties:

    * bootstrapAsynchronously=true|false - whether the bootstrap happens in the background

      after the cache has started. If false, bootstrapping must complete before the cache is

      made available. The default value is true.

    * maximumChunkSizeBytes=<integer> - Caches can potentially be very large, larger than the

      memory limits of the VM. This property allows the bootstraper to fetched elements in

      chunks. The default chunk size is 5000000 (5MB).

    Cache Exception Handling

    By default, most cache operations will propagate a runtime CacheException on failure. An

    interceptor, using a dynamic proxy, may be configured so that a CacheExceptionHandler can

    be configured to intercept Exceptions. Errors are not intercepted.

    It is configured as per the following example:

      <cacheExceptionHandlerFactory class="com.example.ExampleExceptionHandlerFactory"

                                      properties="logLevel=FINE"/>

    Caches with ExceptionHandling configured are not of type Cache, but are of type Ehcache only,

    and are not available using CacheManager.getCache(), but using CacheManager.getEhcache().

    Cache Loader

    A default CacheLoader may be set which loads objects into the cache through asynchronous and

    synchronous methods on Cache. This is different to the bootstrap cache loader, which is used

    only in distributed caching.

    It is configured as per the following example:

        <cacheLoaderFactory class="com.example.ExampleCacheLoaderFactory"

                                      properties="type=int,startCounter=10"/>

    Cache Extension

    CacheExtensions are a general purpose mechanism to allow generic extensions to a Cache.

    CacheExtensions are tied into the Cache lifecycle.

    CacheExtensions are created using the CacheExtensionFactory which has a

    <code>createCacheCacheExtension()</code> method which takes as a parameter a

    Cache and properties. It can thus call back into any public method on Cache, including, of

    course, the load methods.

    Extensions are added as per the following example:

         <cacheExtensionFactory class="com.example.FileWatchingCacheRefresherExtensionFactory"

                             properties="refreshIntervalMillis=18000, loaderTimeout=3000,

                                         flushPeriod=whatever, someOtherProperty=someValue ..."/>

    -->

    <!--

    Mandatory Default Cache configuration. These settings will be applied to caches

    created programmtically using CacheManager.add(String cacheName).

    The defaultCache has an implicit name "default" which is a reserved cache name.

    -->

    <defaultCache

            maxElementsInMemory="1000"

            eternal="false"

            timeToIdleSeconds="120"

            timeToLiveSeconds="120"

            overflowToDisk="false"

            diskSpoolBufferSizeMB="30"

            maxElementsOnDisk="10000000"

            diskPersistent="false"

            diskExpiryThreadIntervalSeconds="120"

            memoryStoreEvictionPolicy="LRU"

	/>

</ehcache>