Abstract: Disclosed is a method for providing synchronization of a transaction in a data processing system where the transaction involves a plurality of agents participating in the transaction and one coordinator for coordinating the transaction. The agents include at least a middleman which coordinates a set of at least one of the agents. A vote is sent indicating the availability or non-availability to commit from each of the agents to the coordinator. The coordinator determines a commit or backout decision when all the votes are received. A Not Known decision message is sent from the middleman to each of the agents in the set available to commit if the decision is not available at the middleman because of a failure. The Not Known decision message stops resynchronization of each of the available agents. If the middleman has responsibility for resynchronization then, on availability of the decision at the middleman, a resynchronization message is sent to each of the available agents.

Abstract: A method of moving records, stored on a recovery log, which are associated with units of work which have waited for a long time is described. Units of work which have waited for a long time, such as those which are in-doubt have their records copied from a recovery log to a secondary log. When the earliest-written record for this in-doubt unit of work has been copied, a new record called a fork record is written on to the recovery log which has two effects: to subtract the log records currently on the recovery log for this unit of work from the recovery log and to refer to the copied records written on the secondary log. The new record achieves this using two pointers, a pointer to point to the most-recently written record on the recovery log for this unit of work and a pointer to point to the most-recently written record on the secondary log for this unit of work.

Abstract: In a coupled data processing system having multiple users, either in a single system or in a multi-system environment, a coupling facility storage structure is used to provide a log management facility. The log management facility provides for a real time physical log merge of the data written into the log stream without interprocessor communication required to process the records in logical sequence. The log management facility supports concurrent write, delete, browse, and asynchronous off-load to dasd processes across multi-users and multi-systems. The log management facility maintains the log records, independent of the log media, in time sequence. A logical block id is assigned to each log record written so that it can be directly accessed at a later time.