You can configure an eXtreme Scale client based on your requirements such as the need to override settings.
An ObjectGrid XML file can be used to alter settings on the client side. To change the settings on an eXtreme Scale client, you must create an ObjectGrid XML file that is similar in structure to the file that was used for the eXtreme Scale server.
Assume that the following XML file was paired with a deployment policy XML file, and these files were used to start an eXtreme Scale server.
companyGridServerSide.xml <?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"> <bean id="TransactionCallback" className="com.company.MyTxCallback" /> <bean id="ObjectGridEventListener" className="com.company.MyOgEventListener" /> <backingMap name="Customer" pluginCollectionRef="customerPlugins" /> <backingMap name="Item" /> <backingMap name="OrderLine" numberOfBuckets="1049" timeToLive="1600" ttlEvictorType="LAST_ACCESS_TIME" /> <backingMap name="Order" lockStrategy="PESSIMISTIC" pluginCollectionRef="orderPlugins" /> </objectGrid> </objectGrids> <backingMapPluginCollections> <backingMapPluginCollection id="customerPlugins"> <bean id="Evictor" className="com.ibm.websphere.objectGrid.plugins.builtins.LRUEvictor" /> <bean id="MapEventListener" className="com.company.MyMapEventListener" /> </backingMapPluginCollection> <backingMapPluginCollection id="orderPlugins"> <bean id="MapIndexPlugin" className="com.company.MyMapIndexPlugin" /> </backingMapPluginCollection> </backingMapPluginCollections> </objectGridConfig>
On an eXtreme Scale server, the ObjectGrid instance named CompanyGrid behaves as defined by the companyGridServerSide.xml file. By default, the CompanyGrid client has the same settings as the CompanyGrid instance running on the server. However, some of the settings can be overridden on the client, as follows:
The following ObjectGrid XML file can be used to specify some of the attributes and plug-ins on the CompanyGrid client.
companyGridClientSide.xml <?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"> <bean id="TransactionCallback" className="com.company.MyClientTxCallback" /> <bean id="ObjectGridEventListener" className="" /> <backingMap name="Customer" numberOfBuckets="1429" pluginCollectionRef="customerPlugins" /> <backingMap name="Item" /> <backingMap name="OrderLine" numberOfBuckets="701" timeToLive="800" ttlEvictorType="LAST_ACCESS_TIME" /> <backingMap name="Order" lockStrategy="PESSIMISTIC" pluginCollectionRef="orderPlugins" /> </objectGrid> </objectGrids> <backingMapPluginCollections> <backingMapPluginCollection id="customerPlugins"> <bean id="Evictor" className="com.ibm.websphere.objectGrid.plugins.builtins.LRUEvictor" /> <bean id="MapEventListener" className="" /> </backingMapPluginCollection> <backingMapPluginCollection id="orderPlugins"> <bean id="MapIndexPlugin" className="com.company.MyMapIndexPlugin" /> </backingMapPluginCollection> </backingMapPluginCollections> </objectGridConfig>
To create the CompanyGrid client using the companyGridClientSide.xml file, pass the ObjectGrid XML file as a URL to one of the connect methods on the ObjectGridManager.
creating the client for XML ObjectGridManager ogManager = ObjectGridManagerFactory.ObjectGridManager(); ClientClusterContext clientClusterContext = ogManager.connect("MyServer1.company.com:2809", null, new URL( "file:xml/companyGridClientSide.xml"));
You can also override client-side ObjectGrid settings programmatically. Create an ObjectGridConfiguration object that is similar in structure to the server-side ObjectGrid instance. The following code creates a client-side ObjectGrid instance that is functionally equivalent to the client override in the previous section which uses an XML file.
client-side override programmatically ObjectGridConfiguration companyGridConfig = ObjectGridConfigFactory .createObjectGridConfiguration("CompanyGrid"); Plugin txCallbackPlugin = ObjectGridConfigFactory.createPlugin( PluginType.TRANSACTION_CALLBACK, "com.company.MyClientTxCallback"); companyGridConfig.addPlugin(txCallbackPlugin); Plugin ogEventListenerPlugin = ObjectGridConfigFactory.createPlugin( PluginType.OBJECTGRID_EVENT_LISTENER, ""); companyGridConfig.addPlugin(ogEventListenerPlugin); BackingMapConfiguration customerMapConfig = ObjectGridConfigFactory .createBackingMapConfiguration("Customer"); customerMapConfig.setNumberOfBuckets(1429); Plugin evictorPlugin = ObjectGridConfigFactory.createPlugin(PluginType.EVICTOR, "com.ibm.websphere.objectgrid.plugins.builtins.LRUEvictor"); customerMapConfig.addPlugin(evictorPlugin); companyGridConfig.addBackingMapConfiguration(customerMapConfig); BackingMapConfiguration orderLineMapConfig = ObjectGridConfigFactory .createBackingMapConfiguration("OrderLine"); orderLineMapConfig.setNumberOfBuckets(701); orderLineMapConfig.setTimeToLive(800); orderLineMapConfig.setTtlEvictorType(TTLType.LAST_ACCESS_TIME); companyGridConfig.addBackingMapConfiguration(orderLineMapConfig); List ogConfigs = new ArrayList(); ogConfigs.add(companyGridConfig); Map overrideMap = new HashMap(); overrideMap.put(CatalogServerProperties.DEFAULT_DOMAIN, ogConfigs); ogManager.setOverrideObjectGridConfigurations(overrideMap); ClientClusterContext client = ogManager.connect(catalogServerAddresses, null, null); ObjectGrid companyGrid = ogManager.getObjectGrid(client, objectGridName);
The ObjectGridManager instance ogManager checks for overrides only in the ObjectGridConfiguration and BackingMapConfiguration objects that you include in the overrideMap Map. For instance, the previous code overrides the number of buckets on the OrderLine Map. However, the Order map remains unchanged on the client side because no configuration for that map is included.
Client-side ObjectGrid settings can also be overridden using the Spring Framework. The following example XML file shows how to build an ObjectGridConfiguration element, and use it to override some client side settings. This example calls the same APIs that are demonstrated in the programmatic configuration. The example is also functionally equivalent to the example in the ObjectGrid XML configuration.
client configuration with Spring <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <bean id="companyGrid" factory-bean="manager" factory-method="getObjectGrid" singleton="true"> <constructor-arg type="com.ibm.websphere.objectgrid.ClientClusterContext"> <ref bean="client" /> </constructor-arg> <constructor-arg type="java.lang.String" value="CompanyGrid" /> </bean> <bean id="manager" class="com.ibm.websphere.objectgrid.ObjectGridManagerFactory" factory-method="getObjectGridManager" singleton="true"> <property name="overrideObjectGridConfigurations"> <map> <entry key="DefaultDomain"> <list> <ref bean="ogConfig" /> </list> </entry> </map> </property> </bean> <bean id="ogConfig" class="com.ibm.websphere.objectgrid.config.ObjectGridConfigFactory" factory-method="createObjectGridConfiguration"> <constructor-arg type="java.lang.String"> <value>CompanyGrid</value> </constructor-arg> <property name="plugins"> <list> <bean class="com.ibm.websphere.objectgrid.config.ObjectGridConfigFactory" factory-method="createPlugin"> <constructor-arg type="com.ibm.websphere.objectgrid.config.PluginType" value="TRANSACTION_CALLBACK" /> <constructor-arg type="java.lang.String" value="com.company.MyClientTxCallback" /> </bean> <bean class="com.ibm.websphere.objectgrid.config.ObjectGridConfigFactory" factory-method="createPlugin"> <constructor-arg type="com.ibm.websphere.objectgrid.config.PluginType" value="OBJECTGRID_EVENT_LISTENER" /> <constructor-arg type="java.lang.String" value="" /> </bean> </list> </property> <property name="backingMapConfigurations"> <list> <bean class="com.ibm.websphere.objectgrid.config.ObjectGridConfigFactory" factory-method="createBackingMapConfiguration"> <constructor-arg type="java.lang.String" value="Customer" /> <property name="plugins"> <bean class="com.ibm.websphere.objectgrid.config.ObjectGridConfigFactory" factory-method="createPlugin"> <constructor-arg type="com.ibm.websphere.objectgrid.config.PluginType" value="EVICTOR" /> <constructor-arg type="java.lang.String" value="com.ibm.websphere.objectgrid.plugins.builtins.LRUEvictor" /> </bean> </property> <property name="numberOfBuckets" value="1429" /> </bean> <bean class="com.ibm.websphere.objectgrid.config.ObjectGridConfigFactory" factory-method="createBackingMapConfiguration"> <constructor-arg type="java.lang.String" value="OrderLine" /> <property name="numberOfBuckets" value="701" /> <property name="timeToLive" value="800" /> <property name="ttlEvictorType"> <value type="com.ibm.websphere.objectgrid. TTLType">LAST_ACCESS_TIME</value> </property> </bean> </list> </property> </bean> <bean id="client" factory-bean="manager" factory-method="connect" singleton="true"> <constructor-arg type="java.lang.String"> <value>localhost:2809</value> </constructor-arg> <constructor-arg type="com.ibm.websphere.objectgrid.security. config.ClientSecurityConfiguration"> <null /> </constructor-arg> <constructor-arg type="java.net.URL"> <null /> </constructor-arg> </bean> </beans>
After creating the XML file, load the file and build the ObjectGrid with the following code snippet.
BeanFactory beanFactory = new XmlBeanFactory(new UrlResource("file:test/companyGridSpring.xml")); ObjectGrid companyGrid = (ObjectGrid) beanFactory.getBean("companyGrid");
Read about integrating with the Spring framework for more information.
The near cache is enabled by default when locking is configured as optimistic or none. Clients do not maintain a near cache when the locking setting is configured as pessimistic.
To disable the near cache, you must set the numberOfBuckets attribute to 0 in the client override ObjectGrid descriptor file.
Read about map entry locking for more information.