6.2. Local Mode

Using Red Hat JBoss Data Grid's local mode instead of a map provides a number of benefits.
Caches offer features that are unmatched by simple maps, such as:
  • Write-through and write-behind caching to persist data.
  • Entry eviction to prevent the Java Virtual Machine (JVM) running out of memory.
  • Support for entries that expire after a defined period.
JBoss Data Grid is built around a high performance, read-based data container that uses techniques such as optimistic and pessimistic locking to manage lock acquisitions.
JBoss Data Grid also uses compare-and-swap and other lock-free algorithms, resulting in high throughput multi-CPU or multi-core environments. Additionally, JBoss Data Grid's Cache API extends the JDK's ConcurrentMap, resulting in a simple migration process from a map to JBoss Data Grid.

6.2.1. Configure Local Mode (Remote Client-Server Mode)

A local cache can be added to any cache container. The following example demonstrates how to add the local-cache element.

Procedure 6.2. The local-cache Element

<cache-container name="local"
                  default-cache="default" 
                  statistics="true">
         <local-cache name="default"
                          start="EAGER"
                          batching="false"
                          statistics="true">
                  <indexing index="NONE">
	                <property name="default.directory_provider">ram</property>
                  </indexing>
         </local-cache>
The local-cache element specifies information about the local cache used with the cache container using the following parameters:
  1. The name parameter specifies the name of the local cache to use.
  2. The start parameter indicates when the cache container starts, i.e. whether it will start lazily when requested or "eagerly" when the server starts up. Valid values for this parameter are EAGER and LAZY.
  3. The batching parameter specifies whether batching is enabled for the local cache.
  4. If statistics are enabled at the container level, per-cache statistics can be selectively disabled for caches that do not require monitoring by setting the statistics attribute to false.
  5. The index attribute of the indexing parameter specifies the type of indexing used for the local cache. Valid values for this attribute are NONE, LOCAL and ALL.
Alternatively, create a DefaultCacheManager with the "no-argument" constructor. Both of these methods create a local default cache.
Local and clustered caches are able to coexist in the same cache container, however where the container is without a <transport/> it can only contain local caches. The container used in the example can only contain local caches as it does not have a <transport/>.
The cache interface extends the ConcurrentMap and is compatible with multiple cache systems.

6.2.2. Configure Local Mode (Library Mode)

In Red Hat JBoss Data Grid's Library mode, setting a cache's mode parameter to local equals not specifying a clustering mode at all. In the case of the latter, the cache defaults to local mode, even if its cache manager defines a transport.
Set the cluster mode to local as follows:
<clustering mode="local" />