International Business Machines Corporation

Lenovo (Singapore) Pte. Ltd.

Paul Hopewell

Paul Kettley

Stephen James Hobson

Peter Siddall

Robert Daniel Millar

Stephen Richard Walker

David James Fisher

Dermot Flaherty

Robert F Buxton

Jeffrey Mark Nick

Jose Emir Garza

James H Warnes

Pete Siddall

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.

Recovery from failures within data processing systems

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

Provided are a method, computer program product and system for providing indexed queue support for efficient retrieval of messages from a queue. An index key for expediting message retrieval is assigned to a message when the operation of placing the message on a queue is committed. The index key assigned at commit time comprises an attribute (such as a message ID or correlation ID) specified by the sending application program, which placed the message on the queue. This deferred assignment of an index key until commit time means that the index key can be used to search for messages having the particular attribute without any possibility of identifying messages for retrieval before the messages have been committed. This maintains transactional requirements of a transaction-oriented messaging system which requires a message to only be made available for retrieval by receiver application programs after the sender application's put operation has committed.

Implementing a message queuing interface (MQI) indexed queue support that adds a key to the index on put commit

The invention relates to the recovery of data in a database of database records, following a failure of a media containing said database. The data recovery uses a backup of the database and a log of log records detailing any changes in the database which are not captured in the backup. The log is replayed starting with the most recent log record. It is the determined for each successive log record, that relates to an operation on a database record, whether processing the log record will result in the most recent state of the corresponding database record, and if so, the log record is processed. Subsequently additional data is restored from the backup.

Data recovery system

A data processing arrangement () and method for fuzzy backup and restore of MQSeries shared queues held in coupling facility list structure (). Periodically backups are taken of the data held in the CF list structure by backing up messages in the sequence uncommitted puts (), committed puts (), uncommitted gets () and expired messages (), whereby all messages may be backed up in the backup means except for exceptions which are recorded in the record log. In the event of media failure of the coupling facility, data can be restored by restoring messages in the sequence restoring messages from the backup means (), replaying messages from the record log means () and determining final disposition of messages from replay of the record log means (). This provides the advantage of allowing the number of log records written to be reduced.

Data processing arrangement and method

A data processing system () and method for creating a fuzzy backup () only of objects older than a predetermined threshold, and restoring from the fuzzy backup and from a record log () replayed from a time equal to the predetermined threshold before the fuzzy backup start time. This provides advantages of reduced resource cost for the fuzzy backup and reduced restore time.

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Chandlers Ford, United Kingdom

Paul Hopewell