MVS/ESA message transport system using the XCF coupling facility

摘要

An asynchronous transport mechanism is provided for use between two or more MVS/ESA tasks on the same or different platforms using the IBM XCF facility, a global directory and a message queuing if tasks are not currently waiting for the messages arrival. A message sending task specifies a named task, which is the name of a group comprised of one or more interested message receiving tasks, that can have access to the message. The sending task is not aware of the number of receiving tasks and is only responsible for registering with a global directory and sending a single message. The message receiving task is not aware of the number of sending tasks and is only responsible for registering with a global directory and receiving a message. Two messaging options are provided to allow the task to emulate two popular types of functions. The first option allows messages to be mirrored to two or more tasks for reliability. If one task abnormally terminates the others will have duplicate data and hence continue processing without interruption. Option two allows one task to receive all the messages until it terminates. A second named task that has been in standby mode would then automatically pick up the messages and takeover processing without any message loss.