Abstract: 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.

Abstract: A data processing arrangement (100) and method for fuzzy backup and restore of MQSeries shared queues held in coupling facility list structure (106). Periodically backups are taken of the data held in the CF list structure by backing up messages in the sequence uncommitted puts (220), committed puts (230), uncommitted gets (240) and expired messages (250), 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 (320), replaying messages from the record log means (340) and determining final disposition of messages from replay of the record log means (350). This provides the advantage of allowing the number of log records written to be reduced.

Abstract: A data processing system (100) and method for creating a fuzzy backup (116) only of objects older than a predetermined threshold, and restoring from the fuzzy backup and from a record log (114) 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.

Abstract: The invention relates to communicating message data between application programs, the message data relating to units of work performed by the application programs. A plurality of message queuing subsystems interface to the application programs and are coupled together through a coupling facility. The message data is communicated in shared queues between the message queuing subsystems by means of data structures contained in the coupling facility. The data structures include an administrative structure listing unit of work descriptors describing operations performed by the queuing subsystems on a shared queue. A connection failure between a queuing subsystem and the shared queue is notified to the remaining queuing subsystems connected to the shared queue.

Abstract: Provided are methods, data processing systems, recovery components and computer programs for recovering from failures affecting data repositories. In a data processing system in which updates applied to a data repository are applied within transactional units of work, a secondary copy is stored of data items held within the data repository and updates applied to the data repository within transactional units of work. In response to a failure affecting a primary copy of the data repository, the secondary copy is used to identify a set of operations required for restoring data items and applied updates to the primary copy of the data repository. The set of operations are analyzed to determine the state, at the time of the failure, of each unit of work corresponding to one or more operations of the identified set of restore operations.

Abstract: The invention provides a restart mechanism within a data processing system for restarts following a failure. The mechanism is provided in persistent storage as a recovery log containing recovery log records which can be used during recovery from the failure of the data processing system. The log records relate to units of work undertaken by the data processing system, and the mechanism retrieves, from the recovery log, a recovery log record relating to a unit of work, determines whether or not the unit of work meets at least one predetermined criterion, and performs a recovery process if the unit of work meets the predetermined criterion.

Abstract: Provided are a method and apparatus for providing serialization support for computer systems and computer system resources, in particular for application programs which require sequencing and/or consistency of data. The computer system resource includes serialized processes with units of work. A serialization token is provided at the start of a serialized process including at least one unit of work. The serialization token remains in force until the or all of the units of work of the process have been committed or rolled back. The serialization token controls the commencement of other processes of the computer system during the time that it is in force. The serialization is carried out by storing an abstract representation of the process to be serialized in storage which is accessible by all the programs and computers where the serialization applies.

Abstract: A data processing arrangement (100) and method for fuzzy backup and restore of MQSeries shared queues held in coupling facility list structure (106). Periodically backups are taken of the data held in the CF list structure by backing up messages in the sequence uncommitted puts (220), committed puts (230), uncommitted gets (240) and expired messages (250), 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 (320), replaying messages from the record log means (340) and determining final disposition of messages from replay of the record log means (350). This provides the advantage of allowing the number of log records written to be reduced.

Abstract: 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.

Abstract: A data processing system (100) and method for creating a fuzzy backup (116) only of objects older than a predetermined threshold, and restoring from the fuzzy backup and from a record log (114) replayed from a time equal to the predetermined threshold before the fuzzy backup start time.

Abstract: 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 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.

Abstract: Provided are a method and apparatus for providing serialization support for computer systems and computer system resources, in particular for application programs which require sequencing and/or consistency of data. The computer system resource includes serialized processes with units of work. A serialization token is provided at the start of a serialized process including at least one unit of work. The serialization token remains in force until the or all of the units of work of the process have been committed or rolled back. The serialization token controls the commencement of other processes of the computer system during the time that it is in force. The serialization is carried out by storing an abstract representation of the process to be serialized in storage which is accessible by all the programs and computers where the serialization applies.

Abstract: The invention relates to communicating message data between application programs, the message data relating to units of work performed by the application programs. A plurality of message queuing subsystems interface to the application programs and are coupled together through a coupling facility. The message data is communicated in shared queues between the message queuing subsystems by means of data structures contained in the coupling facility. The data structures include an administrative structure listing unit of work descriptors describing operations performed by the queuing subsystems on a shared queue. A connection failure between a queuing subsystem and the shared queue is notified to the remaining queuing subsystems connected to the shared queue.

Abstract: The present invention relates to a data processing system and method as well as to a computer program product for realizing such a data processing system and method. Conventionally, access to system resources is controlled within, for example, MQSeries, via security settings or security definition contained within profiles that are used to initialize a data processing system. Typically, each computer program or user has associated access permissions which may, from time to time, be varied by a system administrator. It will be appreciated that to issue on a resource by resource or user by user basis individual changes to access permission would require a significant amount of work. Suitably, the present invention provides a system and method for implementing grouping of security access control for a number of resources or users. Therefore, a single security change request can be used to effect a change of access permissions associated with a number of separate or at least closely coupled resources.

Abstract: The invention provides a restart mechanism within a data processing system for restarts following a failure. The mechanism is provided in persistent storage as a recovery log containing recovery log records which can be used during recovery from the failure of the data processing system. The log records relate to units of work undertaken by the data processing system, and the mechanism retrieves, from the recovery log, a recovery log record relating to a unit of work, determines whether or not the unit of work meets at least one predetermined criterion, and performs a recovery process if the unit of work meets the predetermined criterion.