International Business Machines Corporation

David Y Hu

Robert O Dryfoos

Shawfu Chen

Allan Feldman

Peter Grimm Sutton

Mei-Hui Wang

Jason A Keenaghan

Peter A Lewis

Alice M Williams-Obleton

Wei-Yi Xiao

Masashi E Miyake

A plurality of batch lists are maintained by a channel in order to improve the efficiency of the channel in performing messaging between a sender and a receiver. For example, a Next Batch list is used to prefetch messages to be sent to the receiver from the sender; a Current Batch list includes the messages currently being transmitted to the receiver or waiting confirmation; and an Acknowledged Batch List includes the messages confirmed by the receiver. This allows the functions of prefetching messages, sending messages and deleting confirmed messages to be performed in parallel.

Method, system and program storage device for accessing memory to perform messaging using a channel coupled to a sender and a receiver

Performance of channels used in communicating between senders and receivers

A highly available, high-performance memory queue. Locking of the queue is minimized in order to provide a highly available queue and to improve performance of the queue. Multiple updates of the queue can occur under a single lock. Further, messages of the queue are persistent. A time-initiated checkpointing process, as well as the storing of message information on a recovery log, ensures the persistence of the queue messages.

High-performance memory queue

Memory resident queues are monitored at predefined time intervals. When the monitoring indicates that a particular queue is not being serviced at a desired level, then action is taken to sweep one or more messages from the queue. The sweeping of the messages frees up system resources associated with the messages, thus allowing other tasks to be serviced. If, after the sweeping, it is determined that the queue can handle additional messages, then one or more messages are placed back on the queue.

Managing memory resident queues to control resources of the systems using the queues

When a processor becomes inactive, queues resident in the memory of that processor become inaccessible. Thus, in order to access those queues, an active processor takes over ownership of one or more of the inaccessible queues. Each queue may be rebuilt prior to its take over to ensure that it has up-to-date information.

Reconstructing memory residents queues of an inactive processor

A method and apparatus for switching messages from a primary message channel to a secondary message channel in a message queuing system in which messages are placed in a first transmission queue of a local system for transmission to a remote system via a primary message channel. A local queue manager continuously checks to see whether a high water mark has been reached in the first transmission queue, indicating an apparent failure in the primary message channel. On determining such an apparent failure in the primary message channel, the queue manager determines whether the secondary message channel is associated with the first transmission queue. If so, the queue manager activates the secondary message channel to serve said first transmission queue. If, on the other hand, the secondary message channel is associated with another transmission queue, the queue manager transfers messages already in the first queue to the other queue and redirects any new messages intended for the first queue to the other queue. If the other transmission queue was previously empty, the secondary message channel is activated by a trigger to serve the other queue.

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Poughkeepsie, NY, United States of America

David Y Hu