WebSphere eXtreme Scale Administration Guide > Configure WebSphere eXtreme Scale > Loaders

Configure a JPA time-based data updater

You can configure a time-based database update using XML for a local or distributed eXtreme Scale configuration. You can also configure a local configuration programmatically.

For more information about how the Java™ Persistence API (JPA) time-based data updater works, see JPA time-based data updater.

Procedure

Create a timeBasedDBUpdate configuration.

• With an XML file:

  The following example shows an objectgrid.xml file that contains a timeBasedDBUpdate configuration:

  JPA time-based updater - XML example
  <?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="changeOG" 
              entityMetadataXMLFile="userEMD.xml">
             
  <backingMap name="user" >
                 
  <timeBasedDBUpdate timestampField="rowChgTs" 
                        persistenceUnitName="userderby" 
                        entityClass="com.test.UserClass"
                        mode="INVALIDATE_ONLY"
                 />
             
  </backingMap>
         
  </objectGrid>
     
  </objectGrids>
     
  <backingMapPluginCollections>
  </objectGridConfig>
  

  In this example, the map "user" is configured with time-based database update. The database update mode is INVALIDATE_ONLY, and the timestamp field is rowChgTs.

  When the distributed ObjectGrid "changeOG" is started in the container server, a time-based database update thread is automatically started in partition 0.

• Programmatically:

  If you create a local ObjectGrid, you can also create a TimeBasedDBUpdateConfig object and set it on the BackingMap instance:

  public void setTimeBasedDBUpdateConfig(TimeBasedDBUpdateConfig dbUpdateConfig);
  

  For more information about setting an object on the BackingMap instance, see BackMap interface

  Alternatively, you can annotate the timestamp field in the entity class using the com.ibm.websphere.objectgrid.jpa.dbupdate.annotation.Timestamp annotation. By configuring the value in the class, you do not have to configure the timestampField in the XML configuration.

What to do next

Start the JPA time-based data updater. See Start the JPA time-based updater for more information.

Parent topic

Loaders

Related concepts

Loaders

Loader configuration

Related tasks

Configure JPA loaders

Troubleshoot loaders

Related reference

Write-behind dumper class sample code

+

Search Tips   |   Advanced Search