Method and apparatus for improving message availability in a subsystem which supports shared message queues

摘要

The invention relates to communicating message data between application programs, the message data relating to units of work performed by the application programs. A plurality of message queuing subsystems interface to the application programs and are coupled together through a coupling facility. The message data is communicated in shared queues between the message queuing subsystems by means of data structures contained in the coupling facility. The data structures include an administrative structure listing unit of work descriptors describing operations performed by the queuing subsystems on a shared queue. A connection failure between a queuing subsystem and the shared queue is notified to the remaining queuing subsystems connected to the shared queue. The remaining queuing subsystems interrogate the listed work descriptors so as to identify and to share between them the units of work active in the failed connection, and each of the remaining subsystems recovers its share of the units of work active in the failed connection.