International Business Machines Corporation

Dennis Jack Zimmer

Timothy William Banks

Peter James Lupton

Ian Hunter

Jeffrey Mark Nick

Glyn Normington

John Simon Tilling

Mark Phillips

Robert Vaughn Geiner

James H Warnes

Robert F Buxton

Ian Geoffrey Redding

Michael Casson Bailey

Handel Glasnant Price

Adam Richards

Disclosed are a method, system and computer program product for progressively improving the fit of a pool of reusable environments to requirements of programs in a computer system. The method comprises steps of: providing a first environment for a first program; responsive to initiation of a second program, making a determination whether creation of a new environment is a best response; responsive to a determination that creation of a new environment is a best response, creating a new environment for the second program; responsive to a determination that creating a new environment is not a best response, testing the pool for a best fit environment; and adding elements to the best fit environment to match requirements of the second program, unless the best fit environment already matches the requirements of the second program.

Method, program product and computer system for progressive improvement of an environment pool

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. If the middleman does not have responsibility for resynchronization, then a Known decision message is sent to each of the available agents from the middleman. Receipt of the Known decision message starts resynchronization of each of the available agents.

Optimized synchronization procedure

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.

Management of units of work on a computer system log

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.

Method and system for log management in a coupled data processing system

Growing community of inventors

Chandlers Ford, United Kingdom

Dennis Jack Zimmer