After a failure in either the coordinator or any participants, automatic in-doubt resolution is accomplished when the communication between the coordinator and the participants is reestablished. When the interface to the participants is started using /START SUBSYS (for IMS) or DAFC START (for CICS), the participants’ logs are presented to the coordinator. For each in-doubt logical unit of work, the coordinator informs the participants whether the updates should be committed or rolled back, based on information recorded in the coordinator log.