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 Apache DirectMemory EHCache Integration
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 Olivier Lamy
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 2012-06-17
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EHCache Integration

 You can mix the use of the ehcache framework with DirectMemory. Recent versions of ehcache have some features to store elements
  in a heap off storage when overflow a number of objects or bytes in heap cache.


 First you need to declare dependency to the DirectMemory ehcache integration:

+------------------------
  <dependency>
    <groupId>org.apache.directmemory</groupId>
    <artifactId>directmemory-ehcache</artifactId>
    <version>${currentRelease}</version>
  </dependency>
+------------------------

  Note the heap off cache class to use is not currently configurable in ehcahce see issue {{{https://jira.terracotta.org/jira/browse/EHC-940}https://jira.terracotta.org/jira/browse/EHC-940}}.
  So Apache DirectMemory contains same package/class name as needed by ehcache.

  Activate the feature in ehcache:

+------------------------
  CacheConfiguration cacheConfiguration = new CacheConfiguration();
  cacheConfiguration.setName( "foo" );

  cacheConfiguration.setOverflowToOffHeap( true );

  cacheConfiguration.setMaxBytesLocalHeap( Long.valueOf( 100 * 1024 * 1024 ) );
  cacheConfiguration.setMaxBytesLocalOffHeap( Long.valueOf( 100 * 1024 * 1024 ) );

  Cache cache = new Cache( cacheConfiguration );
  CacheManager.getInstance().addCache( cache );
+------------------------