Configuring an evictor for the near cache

To control the size of the near cache, configure a client-side override that enables an evictor on the client.

• XML file configuration:
  Use the following ObjectGrid XML file as an example to create a client-side configuration file to configure an evictor for the near cache.

  <?xml version="1.0" encoding="UTF-8"?>
  <objectGridConfig xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://ibm.com/ws/objectgrid/config ../objectGrid.xsd"
    xmlns="http://ibm.com/ws/objectgrid/config">      
    <objectGrids>
      <objectGrid name="CompanyGrid">
        <backingMap name="Customer" nearCacheEnabled="true"
          pluginCollectionRef="customerPlugins" />
      </objectGrid>
    </objectGrids>
    <backingMapPluginCollections>
      <backingMapPluginCollection id="customerPlugins">
        <!-- Limit the near cache size to 53*1000=53,000 entries using a least recently used algorithm -->
        <bean id="Evictor" className="com.ibm.websphere.objectgrid.plugins.builtins.LRUEvictor">
         <property name="numberOfLRUQueues" type="int" value="53" description="set number of LRU queues" />
         <property name="maxSize" type="int" value="1000" description="set max size for each LRU queue" />
      </backingMapPluginCollection>
    </backingMapPluginCollections>
  </objectGridConfig>

• Programmatic configuration:

  Use the following code snippet to programmatically configure an LRU evictor for the near cache:

  ObjectGridConfiguration companyGridConfig = ObjectGridConfigFactory
    .createObjectGridConfiguration("CompanyGrid");
  BackingMapConfiguration customerMapConfig = ObjectGridConfigFactory
    .createBackingMapConfiguration("Customer");
  Plugin evictorPlugin = ObjectGridConfigFactory.createPlugin(PluginType.EVICTOR,
    "com.ibm.websphere.objectgrid.plugins.builtins.LRUEvictor");
  ConfigProperty numQueues=ObjectGridConfigFactory.createConfigProperty(ConfigPropertyType.INT_PRIM, 
    "numberOfLRUQueues", "53");
  evictorPlugin.addConfigProperty(numQueues);
  ConfigProperty maxSize=ObjectGridConfigFactory.createConfigProperty(ConfigPropertyType.INT_PRIM,
    "maxSize", "1000");
  evictorPlugin.addConfigProperty(maxSize);
  customerMapConfig.addPlugin(evictorPlugin);
  companyGridConfig.addBackingMapConfiguration(customerMapConfig);
  ClientClusterContext client = ogManager.connect(catalogServerEndpoints, null, null);
  ObjectGrid companyGrid = ogManager.getObjectGrid(client, objectGridName,companyGridConfig);