International Business Machines Corporation

Timothy William Banks

Dennis Jack Zimmer

Glyn Normington

Peter James Lupton

Ian Hunter

Ian Geoffrey Redding

Michael Casson Bailey

Kevin John Turner

Paul Weeden

David John Wyatt

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

Mechanisms for change management of interfaces in a distributed computer system are provided in which there are multiple versions of an interface describing communication between distributed client and server applications. The mechanisms include providing an indication with a response to an operation of an interface that an alternative interface is available. The information can include: a time interval in which a client application must contact a server application using the version of the interface, a reference to a succeeding version of the interface; and/or an indication of an expiry date and time of an interface. The interface itself is used to communicate version and validity information and change to client applications.

Change management of interfaces in distributed computer systems

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

Disclosed is a method for providing synchronization of a transaction in a data processing system where the transaction involves an initiator node, which starts said synchronization, and a coordinator node, which decides the outcome of said transaction. The initiator node and the coordinator node communicate through a routing node. The routing node has no resources of its own which are modified in the transaction. The synchronization is provided by establishing a first conversation between the initiator node and the routing node and a second conversation between the routing node and the coordinator node. A first commit request message is then sent from said initiator node to the routing node. A second commit request message is sent from the routing node to the coordinator node. An additional step is performed of storing asynchronously, checkpoint information to non-volatile storage in the routing node after establishing the first and second conversations and before sending said second commit request message. The routing node acts as just a routing node and does not save checkpoint state as if it were a node with a real need to do so. In the event of failure the routing node only recovers the routing information, that is the end points of the conversation it was routing when failure occurred. The resynchronization protocols are carried between the end points with the routing node not aware of their contents, except to monitor when it can safely forget its routing information.

Synchronization procedure in a routing node

Disclosed is a data processing system and a method of managing a queue 130 of items for processing in which the expected time an item will spend on the queue 130 is calculated 209 when an item is received to be placed on a queue 130. If this exceeds an upper limit, then the item is rejected 213 and the queue 130 is purged 215 of all items. An indication is provided to the sources of the items that were purged that this has occurred. In this way, it is possible to detect the difference between a queue 130 which is longer, but dynamic, and one which is shorter, but static. The method is applied to management of requests for a communications link between local and remote systems.

Growing community of inventors

Winchester, United Kingdom

Timothy William Banks