International Business Machines Corporation

Pete Siddall

Stephen James Hobson

Paul Stephen Dennis

Jamie P Squibb

Philip Graham Willoughby

Paul Kettley

Matthew W Leming

Robert Daniel Millar

Paul Hopewell

Stephen Richard Walker

David James Fisher

Richard M W Harran

Colin C Paice

Phillip G Willoughby

A method for aiding resolution of a transaction for use with a transactional processing system comprising a transaction coordinator and a plurality of grouped and inter-connected resource managers, the method comprising the steps of: in response to a communications failure between the transaction coordinator and a first resource manager causing a transaction to have an in-doubt state, connecting, by the transaction coordinator, to a second resource manager; in response to the connecting step, sending by the transaction coordinator to the second resource manager, a resolve request comprising a resolution for the in-doubt transaction; in response to the resolve request, obtaining at the first resource manager, by the second resource manager, a lock to data associated with the in-doubt transaction; and in response to the obtaining step, determining, by the second resource manager, whether the transaction is associated with the first resource manager.

Aiding resolution of a transaction

A computer system defines a list structure on the shared medium wherein the list structure has multiple lists; and provides a list which is allocated to a single queue manager in which message entries are located which belong to multiple shared temporary dynamic queues (STDQs) created by the single queue manager, wherein the message entries are located by reference to a key which determines a message entry's position in the list, the list including: a list header which can be partitioned for multiple current STDQs by assignment of key ranges to message entries belonging each current STDQ; and a list control entry which holds information about the assignment of key ranges to the multiple current STDQs and shares the information with other queue managers using the STDQs, wherein the list control entry is updated by the single queue manager when an STDQ is created or deleted.

Implementing temporary message queues using a shared medium

A computer implemented method, apparatus, and computer program product for determining a state associated with a transaction for use with a transactional processing system comprising a transaction coordinator and a plurality of grouped and inter-connected resource managers, the method comprising the steps of: in response to a communications failure between the transaction coordinator and a first resource manager causing a transaction to have an in doubt state, connecting to a second resource manager; in response to the connecting step, sending by the transaction coordinator to the second resource manager, a query requesting data associated with the in doubt transaction; obtaining at the first resource manager, by the second resource manager, a shared lock to data associated with the in doubt transaction; and in response to the obtaining step, collating, by the second resource manager, data associated with the in doubt transaction associated with the first resource manager.

Method for determining a state associated with a transaction

Disclosed is a method, apparatus, computer program and computer program product for adjusting the frequency at which data is backed up. This involves receiving a target recovery time. A current estimated recovery time is then determined and the current and target times are compared. If it is determined that the current estimated recovery time has reached a predetermined threshold relative to the received target recovery time a new backup should be initiated.

Method, apparatus, computer program and computer program product for adjusting the frequency at which data is backed up

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Pete Siddall