18.104.22.168 Timer Events on PDC
When the PDC timer expires, the PDC MUST prepare the announcement message (as specified in section 22.214.171.124.1) using the current database state, and send the message to BDCs that need synchronization. A BDC needs database synchronization if one of the following conditions is true:
The announcement is forced as a result of administrative action.
The BDC database serial number is less than the PDC database serial number for the corresponding database as indicated by an AbstractBdcDatabaseSerialNumbers element corresponding to the BDC and the database. To prevent sending messages to slow or unreachable BDCs, this condition MAY<336> be augmented to require that the BDC finishes processing the previous announcement (if any), or it is timed out before the PDC sends a new announcement message.
More than AbstractMaximumPulse seconds passed since the BDC was sent the previous announcement message.
To reduce the load on the PDC from synchronization requests following the PDC announcement, the PDC MAY<337> choose to send messages only if the current value of AbstractPulseConcurrency is less than a certain value defined as a configuration setting.
The PDC resets its timer to expire in the AbstractPulse seconds.