The ADCD Connector detects and reports changed objects following the chronology of the uSNChanged attribute values: changed objects with lower uSNChanged values will be reported before changed objects with higher uSNChanged values.
The Connector executes an LDAP query of type (usnChanged>=X) where X is the USN number that represents the current synchronization state. Sort and Page LDAP v3 controls are used with the search operation and provide for chronology of changes and ability to process large result sets. The Show Deleted LDAP v3 request control (OID "1.2.840.113556.1.4.417") is used to specify that search results should include deleted objects as well.
The ADCD Connector consecutively reports all changed objects regardless of interruptions, regardless of when it is started and stopped and whether the changes happened while the Connector was online or offline. Synchronization state is kept by the Connector and saved in the User Property Store – after each reported changed object the Connector saves the USN number necessary to continue from the correct place in case of interruption and restart.
The Connector will signal end of data and stop (according to the timeout value) when there are no more changes to report.
When there are no more changed Active Directory objects to retrieve, the Active Directory Connector cycles, waiting for a new object change in Active Directory. The Sleep Interval parameter specifies the number of seconds between two successive polls when the Connector waits for new changes. The Connector loops until a new Active Directory object is retrieved or the timeout (specified by the Timeout parameter) expires. If the timeout expires, the Active Directory Connector returns a null Entry, indicating there are no more Entries to return. If a new Active Directory object is retrieved, it is processed as previously described, and the new Entry is returned by the Active Directory Connector.
In older versions of the Connector, it reported both added and modified entries as updated. Currently, the Connector differentiates between add and modify and reports each operation separately (for details see Offline and Paged results cases.)
The ADCD Connector delivers changed Active Directory objects as they are, with all their current attributes. It does not determine which object attributes have changed, nor how many times an object has been modified. All intermediate changes to an object are irrevocably lost. Each object reported by the Active Directory Connector represents the cumulative effect of all changes performed to that object. The Active Directory Connector, however, recognizes the type of object change that has to be performed on the replicated data source and reports whether the object must be updated or deleted in the replicated data source.