Synchronization types

In any reconciliation operation, there is a source system (the system that contains the changes) and a target system (the system to which the changes will be propagated). The source and target system are defined in a mapping. The IDM repository can be either the source or the target in a mapping. You can configure multiple mappings for one IDM instance, depending on the external resources to which you are connecting.

To perform reconciliation, IDM analyzes both the source system and the target system, to discover the differences between them. Reconciliation can therefore be a heavyweight process. When working with large data sets, finding all changes can be more work than processing the changes.

Reconciliation is very thorough. It recognizes system error conditions and catches changes that might be missed by liveSync, and therefore serves as the basis for compliance and reporting.

To perform this polling, liveSync relies on a change detection mechanism on the external resource to determine which objects have changed. The change detection mechanism is specific to the external resource, and can be a time stamp, a sequence number, a change vector, or any other method of recording changes that have occurred on the system. For example, ForgeRock Directory Services (DS) implements a change log that provides IDM with a list of objects that have changed since the last request. Active Directory implements a change sequence number, and certain databases might have a lastChange attribute.

For direct changes to managed objects, IDM immediately synchronizes those changes to all mappings configured to use those objects as their source. A direct change can originate not only as a write request through the REST interface, but also as an update resulting from reconciliation with another resource.