Jackrabbit hangs on unused data

Jackrabbit Repository (JCR) often retains a lot of unused data if you perform migrations from the same repository multiple times. This leads to an increase in table sizes and slowdowns on the repository.

You can clean up this unused data in the JCR by enabling a system listener designed for this purpose. Cleaning up the JCR can only be done with no users logged into it, and the repository remains locked while the process is running.

1. Stop the Pentaho Server.

2. Locate the pentaho-server/pentaho-solutions/scheduler-plugin directory and open the plugin.spring.xml with any text editor.

3. Add the following listener bean:

   <bean id="repositoryCleanerSystemListener" class="org.pentaho.platform.plugin.services.repository.RepositoryCleanerSystemListener">  
   	<property name="gcEnabled" value="true"/>
   	<property name="execute" value="now"/>
   </bean>

4. Add a reference to the listener bean (repositoryCleanerSystemListener) as shown in the following list:

   <util:list id="schedulerLifecycleListenerList" list-class="java.util.ArrayList" value-type="org.pentaho.platform.api.engine.IPluginLifecycleListener">
    <ref bean="embeddedQuartzSystemListener"/>
    <ref bean="embeddedVersionCheckSystemListener"/>
    <ref bean="emailGroupLifecycleListener"/> 
    <ref bean="repositoryCleanerSystemListener"/>
   </util:list>

5. Save and close the plugin.spring.xml file and restart the Pentaho Server.

You can customize the settings for the repositoryCleanerSystemListener by editing these properties. It is best practice to clean up the Jackrabbit repository on a regular schedule.

Property	Description
gcEnabled	A Boolean flag that turns the listener On (true) or Off (false).
execute	You can choose to run the listener:- now runs once during server start-up weekly runs on the first day of each week (Sunday) monthly runs on the first day of each month