If EnlistDuringPrepareRequired is specified during enlistment, the resource manager indicates that it wants to receive a Prepare notification while new enlistments are still allowed for the transaction. A resource manager who acts as a cache for another durable resource, such as a backend database, would probably use this option during enlistment.Quando o recurso de cache obtém sua notificação preparar, transfere o conteúdo para o recurso durável. Fazendo isso, o recurso durável inscreve na transação para se tornar um participante do Protocolo da fase confirmar (2PC) 2. Antes que isso aconteça, apenas o recurso de cache (não o recurso durável) foi inscrito.
If None is specified, the enlistment indicates that it will not receive a Prepare notification until it is too late to create new enlistments in 2PC. In our preceding scenario, if a caching resource specifies this option during enlistment, and attempts to flush its cache during the Prepare notification, the durable resource gets an exception when it attempts on enlisting since it is too late.