International Business Machines Corporation

Jaime F Anaya

David B Petersen

Michael G Fitzpatrick

Paul Michael Cadarette

Jeffrey Mark Nick

David Harold Surman

Bruce Gilbert Lindsay

Michael D Swanson

James C Kleewein

Kelly B Pushong

Ruth A Allen

Ronald Elliott Parrish

Nicolas G Adiba

Lisa M Goetze

Jay A Yothers

Yat On Lau

Elizabeth Belva Hamel

Siqun Li

Roger L Brockmeyer

Guido Rost

Roger L Brookmeyer

Budi Surjanto

Frank Cullen Sherwin

Paul M Cadarettte

John A Kistler

Embodiments include a method, system, and computer program product for maintaining continuous availability. An embodiment of the present invention includes receiving a unit of work data. The unit of work data is distributed among the plurality of workloads using either an active/standby configuration, an active/query configuration, an active/partitioned configuration, or an active/active configuration. A primary workload is selected from a plurality of workloads to process the unit of work data based on a workload distribution rule. It is determined if the primary workload is capable of processing the unit of work data based on user configurable settings. If the primary site is capable of processing the unit of work data then the unit of work data is transmitted to the primary workload. Otherwise the unit of work data is transmitted to a secondary workload. The unit of work data is replicated between the primary workload and the secondary workload.

Variable configurations for workload distribution across multiple sites

Continuous workload availability between sites at unlimited distances, which includes receiving a unit of work data. Once the unit of work data has been received the workload that the unit of work data is directed to is determined, and a primary site of a plurality of sites to process the unit of work is chosen. If the processing of the unit of work data is successful, then one of one or more processing systems of the primary site are selected to process the unit of work data, and the unit of work data is replicated to at least one other site. The primary site is separated from each of the plurality of sites by a distance greater than a metropolitan area network (MAN) and operations occur within a customer acceptability window.

Continuous workload availability between sites at unlimited distances

A continuous availability system including a controller module executing on a computer processor, the system is configured to receive a unit of work and to select a primary site from a plurality of sites to process the unit of work. Once a site is selected the system is further configured to select one of one or more processing systems from the primary site to process the unit of work. The system is additionally configured to replicate the unit of work to at least one other site once the unit of work is completed at the primary site. The system is configured to operate even when the primary site is separated from each of the plurality of sites by a distance greater than a metropolitan area network and the operations occur within a customer acceptability window.

Continuous availability between sites at unlimited distances

A method and system for asynchronously replicating data changes in a database system captures update information for a data update in a source table from a database log, where the data value from the data update is not in the database log. A query is built to obtain the data value from the source table using the update information, including a key column value that identifies the row of the source table in which the data resides. When the key column is also updated in the same or different transaction, the data update information is stored, and the updated key column value is replaced with a later captured key column update value. The query is built and executed, and the data update is replicated at a target table. In this manner, data objects whose values are not recorded in a database log can be asynchronously replicated in a database system.

Algorithm to find LOB value in a relational table after key columns have been modified

A method and system for member initialization to and deactivation from an asynchronous data replication group in a database system is disclosed. The method and system allows new members to be added to the replication group or existing members to be removed from the replication group, without requiring the halting of the asynchronous replication of data. The performance advantages of asynchronous replication are still realized during member initialization or deactivation.

Peer-to-peer replication member initialization and deactivation

Two methods for resolving locking contention for pseudo-deadlocked transactions without rolling back or aborting any of the deadlocked transactions are provided. In one method, one or more shared lock requests from deadlocked transactions are granted ahead of at least one exclusive lock request from a deadlocked transaction. In another method, all shared lock requests from deadlocked transactions are granted ahead of all exclusive lock requests from deadlocked transactions.

Locking contention resolution for shared resources

A method for coordinating phases of program execution within a data processing system. One or more program defined synchronization events are established. Each synchronization event is responded to by one or more programs to coordinate phases of execution. The operating system notifies the one or more programs when all responses are received. A next program defined synchronization event may be established after a response is received for a previous synchronization event.

Method for coordinating executing programs in a data processing system

A method and system for rebuilding storage structures located within one or more structure processing facilities of a data processing system. A connection is made to a first storage structure having a name and one or more predefined characteristics. Thereafter, a second storage structure is allocated having the same name as the first structure, however, one or more of the predefined characteristics of the second structure are different than the predefined characteristics of the first structure. The second structure may be used for planned system reconfigurations or for recovery from system failures. During the rebuilding process, notification of phases of the rebuilding process are given to the active users. Further, a capability is provided for terminating the rebuilding process. In addition, a method and system for coordinating phases of user defined processing is provided.

Method and system for reconfiguring a storage structure within a

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San Jose, CA, United States of America

Jaime F Anaya