Cleaning up shared business objects

When a new version of a shared business object is saved, older versions of the shared business object that are no longer required are automatically deleted. The system performs the cleanup based on the cleanupMaxVersionCount and cleanupMinAge configuration parameters. To specify the versions of the business objects that you want to keep, use wsadmin scripting to modify these configuration parameters. If you migrated your IBM BPM from a version earlier than version 8.5.6, you must change cleanupMaxVersionCount to explicitly enable cleanup.

About this task

When a shared business object is saved, it is required that the original version is still available. In earlier versions of IBM BPM, all versions of shared business objects were kept, and so the original version was always available. Starting with IBM BPM version 8.5.6, the system deletes old versions of business objects that are no longer required. The system keeps track of which BPD instances reference which version of a shared business object. The versions referenced by active BPD instances are never deleted even if they are eligible for deletion according to the configuration parameters. But if you have just migrated to 8.5.6, that information is not available for existing instances, and cleanup is disabled. If you enable cleanup, when a BPD instance becomes active, the system starts tracking the shared business objects referenced by the instance.

The configuration parameters for cleaning up shared business objects are described in the following table:

Configuration parameter Description

cleanupMaxVersionCount

Configuration parameter	Description
cleanupMaxVersionCount	The cleanupMaxVersionCount parameter specifies the number of shared business object versions that you want to keep. For example, a cleanupMaxVersionCount of 4 indicates that at least 4 versions should be kept. For a newly installed IBM BPM, the default for cleanupMaxVersionCount is 5. For a migrated IBM BPM, the default for cleanupMaxVersionCount is -1. The -1 value means that shared business objects are not cleaned up. To enable the cleanup feature, change cleanupMaxVersionCount to a positive integer. Important: Before you enable cleanup, look in your code for shared business objects that do no have automatic synchronization enabled and make sure that load() is called before a change is made to the business object. For example, a script that has the following code: `tw.local.sbo.property = "new value"; tw.local.sbo.save();` Add a call to load() before the property is changed: `tw.local.sbo.load(); tw.local.sbo.property = "new value"; tw.local.sbo.save();` The load() method reloads the latest version from the database into the variable, however it comes with a performance cost. If you have a shared business object variable in a BPD that is not modified (it is not passed to other BPDs, or the BPDs and services to which it is passed do not modifiy it), then your local variable cannot be outdated. In this situation you do not need the load() method.
cleanupMinAge	The cleanupMinAge parameter specifies a time in hours that prevents recent versions from being deleted. For example, a cleanupMinAge of 48 indicates that a version that was created less than 48 hours ago should not be deleted, regardless of the cleanupMaxVersionCount specified. The default for cleanupMinAge is 48 hours for both newly installed and migrated IBM BPM systems. However, cleanupMinAgeis not effective if cleanupMaxVersionCount is not enabled. Use cleanupMinAge to allow users enough time to complete interactions before the data is cleaned up. Set a value that is higher than the time it takes a user to look at a user interface, work on data and click save.

The cleanupMaxVersionCount parameter specifies the number of shared business object versions that you want to keep. For example, a cleanupMaxVersionCount of 4 indicates that at least 4 versions should be kept.

For a newly installed IBM BPM, the default for cleanupMaxVersionCount is 5. For a migrated IBM BPM, the default for cleanupMaxVersionCount is -1. The -1 value means that shared business objects are not cleaned up. To enable the cleanup feature, change cleanupMaxVersionCount to a positive integer.

Important: Before you enable cleanup, look in your code for shared business objects that do no have automatic synchronization enabled and make sure that load() is called before a change is made to the business object. For example, a script that has the following code:

tw.local.sbo.property = "new value";
tw.local.sbo.save();

Add a call to load() before the property is changed:

tw.local.sbo.load();
tw.local.sbo.property = "new value";
tw.local.sbo.save();

The load() method reloads the latest version from the database into the variable, however it comes with a performance cost. If you have a shared business object variable in a BPD that is not modified (it is not passed to other BPDs, or the BPDs and services to which it is passed do not modifiy it), then your local variable cannot be outdated. In this situation you do not need the load() method.

cleanupMinAge

The cleanupMinAge parameter specifies a time in hours that prevents recent versions from being deleted. For example, a cleanupMinAge of 48 indicates that a version that was created less than 48 hours ago should not be deleted, regardless of the cleanupMaxVersionCount specified.

The default for cleanupMinAge is 48 hours for both newly installed and migrated IBM BPM systems. However, cleanupMinAgeis not effective if cleanupMaxVersionCount is not enabled.

Use cleanupMinAge to allow users enough time to complete interactions before the data is cleaned up. Set a value that is higher than the time it takes a user to look at a user interface, work on data and click save.

Example

The following example shows how to read and modify the configuration parameters for cleaning up shared business objects using wsadmin scripting:

// List all BPMSharedBusinessObjects objects. If there is only one deployment environment, then there is only one.
sboConfigurations = AdminUtilities.convertToList(AdminConfig.list("BPMSharedBusinessObjects"))

// Read the first item
sboConfiguration = sboConfigurations[0]

// Show one specific attribute of the Shared Business Object configuration
AdminConfig.showAttribute(sboConfiguration, "cleanupMaxVersionCount")
AdminConfig.showAttribute(sboConfiguration, "cleanupMinAge")

// Update one specific attribute of the Shared Business Object configuration
AdminConfig.modify(sboConfiguration, [["cleanupMaxVersionCount", 4]])
AdminConfig.modify(sboConfiguration, [["cleanupMinAge", 24]])


// Save the configuration
AdminConfig.save()

In this example, at least four versions are kept, but versions that are less than one day old are not deleted because end users might need to look at the data in a coach.