Abstract: Provided are methods, data processing systems, recovery components and computer programs for recovering from storage failures affecting data repositories. At least a part of the recovery processing is performed while the data repositories are able to receive new data and to allow retrieval of such new data. Although new data items may be received into the repository and retrieved therefrom during recovery processing, updates to the data repository which were performed before the failure and which are then restored to the repository by the recovery processing are restored within a recovery unit of work and are inaccessible to processes other than the recovery process until successful completion of the recovery unit of work. The recovery processing ensures that the recovered repository is consistent with the state of the repository at the time of the failure, but is available for addition and retrieval of new data items before completion of the recovery processing.

Abstract: 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.

Abstract: A transaction processing system, adapted for use in a computer system having a host computer running applications and user terminals connected to the host computer, determines the transaction attributes for each transaction received by the host computer and dynamically associates a transaction protocol to be used in processing that particular transaction. The transaction protocol specifies such attributes as synchronization paradigm and flow control. The synchronization paradigm and flow control are used only for as long as the transaction remains in the system and are used only for that transaction.