International Business Machines Corporation

Jon Kim Johnson

Scott Brady Compton

Roman Anthony Bobak

David Lee Meck

William Robert Richardson

Michael Allen Wright

Max M Maurer

Alan F Martens

Christopher Paul Vignola

Scott Andrew Fagen

Lorraine Cramer

John T Gates, Jr

John P Kong

Ramu Mohan

When applications connect to a data pipe, which is located on the same system as the connecting applications, the data pipe is considered a local pipe. That is, local media is used to pipe the data. If, however, an application on a different system is to access the pipe, the pipe is transitioned from a local pipe to a cross-system pipe, in which an alternative non-local media is used to pipe the data. The application causing the transition and any other applications to subsequently connect to the pipe use the cross-system pipe. Any local applications still allocated to the pipe are transitioned, such that they now access the cross-system pipe, instead of the local pipe. Likewise, when an application disconnects from a cross-system pipe, such that all remaining connections to the pipe are local connections, the pipe is transitioned from a cross-system pipe to a local pipe.

Dynamic transitioning from a local pipe to a cross-system pipe

A technique for selectively dummying a data pipe transparent to a writer application is provided. A writer application writes data to a local data pipe or a cross-system data pipe and one or more reader applications read data from the data pipe. The technique involves determining when a last reader application of the at least one or more reader applications closes the data pipe before the writer application has completed writing data to the data pipe. Upon determining this condition, further writing of data to the data pipe by the writer application is transparently prevented. While transparently preventing writing to a dummied data pipe, writing of data to a fitting, e.g., for a permanent record, can proceed.

Selectively dummying a data pipe transparent to a writer application

Data is written to and read from a shared pipe by applications of multiple systems. At least one shared pipe is located within an external shared memory coupled to one or more central processing complexes. Each of the central processing complexes has one or more operating system images, which controls execution of one or more piping applications. At least one piping application corresponding to at least one operating system image writes data to a shared pipe located in the external shared memory and at least one other application corresponding to one or more other operating system images reads data from the same shared pipe, thereby providing cross-system data piping.

Cross-system data piping using an external shared memory

Cross-system data piping method using an external shared memory

Cross-system data piping system using an external shared memory

A computer complex is provided with a mechanism for message delivery and redelivery in a controlled manner through the use of distributed shared memory. This provides a mechanism for overall computer system complex operation from a plurality of consoles which are registered or identified to the system and which particularly enhances capabilities for remote operation. In this way the complex can be made to look like a single system. Direct communication between any pair of systems is provided, say, by channel-to-channel adapters. Message information is maintained in each system which can also communicate with shared storage to establish update level information regarding locally maintained message information.

Multicomputer complex having a distributed shared memory system for

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Jon Kim Johnson