Abstract: A system for providing continuous availability comprises a second computing site that is geographically remote from a first computing site. The second computing site comprises a storage unit configured to store units of work data and data synchronously replicated from the first computing site. The second computing site further comprises a group of workloads configured to process the units of work data asynchronously replicated from the first computing site. The second computing site further comprises a software replication module configured not to replicate any data while the first computing site is available.

Abstract: A mechanism is provided for handling transaction messages in asynchronous data replication in a database system, in which the database system includes a source node and a target node, and each transaction message has information concerning a row change to a table copy at the source node. The mechanism determines whether a first transaction message has a dependency on a preceding non-completed transaction message. Responsive to the first transaction message having a dependency on the preceding non-completed transaction, the mechanism holds the first transaction message, completes the preceding non-completed transaction message including applying the row change associated with the preceding non-completed transaction message to the table copy at the target node, and responsive to completing the preceding non-completed transaction message, and releases the first transaction message and applying the row change associated with the first transaction message to the table copy at the target node.

Abstract: A system for providing reliable availability of a general workload and continuous availability of a priority workload over long distances may include a first computing site configured to execute a first instance associated with the priority workload, wherein the first instance is designated as an active instance, a second computing site configured to execute a second instance of the priority workload, wherein the second instance is designated as a standby instance, a third computing site configured to restart a third instance associated with the general workload, and a workload availability module configured to synchronize a portion of data associated with the third instance with a corresponding portion of data associated with the second instance.

Abstract: A system for maintaining a two-site configuration for continuous availability over long distances may include a first computing site configured to execute a first instance associated with a priority workload, the first instance being designated as an active instance; a second computing site configured to execute a second instance of the priority workload, the second instance being designated as a standby instance; a software replication module configured to replicate a unit of work data associated with the priority workload from a first data object associated with the active instance to a second data object associated with the standby instance, and a hardware replication module configured to replicate an image from a first storage volume to a copy on a second storage volume, wherein the first storage volume is associated with the first computing site, and the second storage volume is associated with a third computing site.

Abstract: A mechanism for handling transaction messages in asynchronous data replication in a database system, in which the database system includes a source node and a target node, and each transaction message has information concerning a row change to a table copy at the source node. The mechanism determines whether a first transaction message has a dependency on a preceding non-completed transaction message. Responsive to the first transaction message having a dependency on the preceding non-completed transaction, the mechanism holds the first transaction message, completes the preceding non-completed transaction message including applying the row change associated with the preceding non-completed transaction message to the table copy at the target node, and responsive to completing the preceding non-completed transaction message, releases the first transaction message and applying the row change associated with the first transaction message to the table copy at the target node.

Abstract: A data processing system and method of operation are disclosed. The data processing system includes a first site for processing data; a second site for processing data; and a transaction replay program configured to send a copy of data from the first site to the second site. A processor defines a maximum replication latency threshold and a reset threshold for the system, estimates a replication latency of a workload the system, switches the system to a first replication latency state when the estimated replication latency rises above the maximum replication latency and switches the system out of the first replication latency state to a second replication latency state when the estimated replication latency falls below the reset threshold.

Abstract: A computer system for managing a plurality of workloads executing on both a primary system and on a secondary system, and synchronizing both a plurality of software data and hardware data stored on the primary system with the secondary system is provided. The computer system may include receiving a region switch request and stopping the execution of the plurality of workloads on the primary system; suspending the replication of the plurality of software and hardware data stored on the primary system with the plurality of software and hardware data stored on the secondary system; and switching the replication of the plurality of software data and the plurality of hardware data that occurs from the primary system to the secondary system to occur from the secondary system to the primary system. The computer system may include activating the execution of and synchronizing the plurality of workloads on the secondary system.

Abstract: Embodiments of the disclosure are directed to methods, systems and computer program products for performing a planned workload switch. A method includes receiving a request to switch a site of an active workload and stopping one or more long running processes from submitting a new request to the active workload. The method also includes preventing a new network connection from accessing the active workload and processing one or more transactions in a queue of the active workload for a time period. Based on a determination that the queue of the active workload is not empty after the time period, the method includes aborting all remaining transactions in the queue of the active workload. The method further includes replicating all remaining committed units of work to a standby workload associated with the active workload.

Abstract: Techniques for restoring point-in-time and transaction consistency across consistency groups between a first and a second independent database management system (DBMS) for a disaster recovery. Several consistency groups (CGs) are defined for replication. For each CG in the first DBMS data changes are transmitted to a second DBMS. A timestamp representing a most recently received commit log record or a heartbeat during periods of inactivity for a CG is stored in a database table at regular intervals. At regular intervals, the timestamp is compared with timestamps for other CGs to identify a common time at which data to be applied to the CGs in the second DBMS have been received into a recoverable data store. The received data is applied to the CGs in the second DBMS up to the common time.

Abstract: Techniques for restoring point-in-time and transaction consistency across consistency groups between a first and a second independent database management system (DBMS) for a disaster recovery. Several consistency groups (CGs) are defined for replication. For each CG in the first DBMS data changes are transmitted to a second DBMS. A timestamp representing a most recently received commit log record or a heartbeat during periods of inactivity for a CG is stored in a database table at regular intervals. At regular intervals, the timestamp is compared with timestamps for other CGs to identify a common time at which data to be applied to the CGs in the second DBMS have been received into a recoverable data store. The received data is applied to the CGs in the second DBMS up to the common time.

Abstract: According to one embodiment of the present invention, a system uses parallel transaction messages for database replication. The system receives transaction messages from a source system via a plurality of parallel send queues in a receive queue. Each transaction message includes a message identifier indicating a commit order for that transaction. The system reads transaction messages in the receive queue in order in which they were committed against a source database based on the message identifier, and applies changes described by the transaction messages to a target database. Two or more transaction messages in the receive queue are applied to the target database in parallel. The system deletes transaction messages from the receive queue asynchronously to applying changes described by those transaction messages to the target database. Embodiments of the present invention further include a method and computer program product for parallel transaction messages in substantially the same manners described above.

Abstract: A system for providing reliable availability of a general workload and continuous availability of a priority workload over long distances may include a first computing site configured to execute a first instance associated with the priority workload, wherein the first instance is designated as an active instance, a second computing site configured to execute a second instance of the priority workload, wherein the second instance is designated as a standby instance, a third computing site configured to restart a third instance associated with the general workload, and a workload availability module configured to synchronize a portion of data associated with the third instance with a corresponding portion of data associated with the second instance.

Abstract: A system for maintaining a two-site configuration for continuous availability over long distances may include a first computing site configured to execute a first instance associated with a priority workload, the first instance being designated as an active instance; a second computing site configured to execute a second instance of the priority workload, the second instance being designated as a standby instance; a software replication module configured to replicate a unit of work data associated with the priority workload from a first data object associated with the active instance to a second data object associated with the standby instance, and a hardware replication module configured to replicate an image from a first storage volume to a copy on a second storage volume, wherein the first storage volume is associated with the first computing site, and the second storage volume is associated with a third computing site.

Abstract: Techniques are disclosed to determine differences between a source table and a target table in a database environment, as being persistent or transient. A first set of differences between the source table and the target table is determined at a first point in time. A second set of differences between the source table and the target table is determined at a second point in time subsequent to the first point in time. At least one of a set of persistent differences and a set of transient differences is determined. The set of persistent differences includes a set intersection of the first and second sets of differences, the set intersection being filtered based on matching non-key values of the differences. The set of transient differences includes a relative complement of the second set of differences in the first set of differences.

Abstract: A method for managing a plurality of workloads executing on both a primary system and on a secondary system, and synchronizing both a plurality of software data and a plurality of hardware data stored on the primary system with the secondary system is provided. The method may include receiving a region switch request and stopping the execution of the plurality of workloads on the primary system; suspending the replication of the plurality of software and hardware data stored on the primary system with the plurality of software and hardware data stored on the secondary system; and switching the replication of the plurality of software data and the plurality of hardware data that occurs from the primary system to the secondary system to occur from the secondary system to the primary system. The method may further include activating the execution of and synchronizing the plurality of workloads on the secondary system.

Abstract: A computer system for managing a plurality of workloads executing on both a primary system and on a secondary system, and synchronizing both a plurality of software data and hardware data stored on the primary system with the secondary system is provided. The computer system may include receiving a region switch request and stopping the execution of the plurality of workloads on the primary system; suspending the replication of the plurality of software and hardware data stored on the primary system with the plurality of software and hardware data stored on the secondary system; and switching the replication of the plurality of software data and the plurality of hardware data that occurs from the primary system to the secondary system to occur from the secondary system to the primary system. The computer system may include activating the execution of and synchronizing the plurality of workloads on the secondary system.

Abstract: Techniques are disclosed to determine differences between a source table and a target table in a database environment, as being persistent or transient. A first set of differences between the source table and the target table is determined at a first point in time. A second set of differences between the source table and the target table is determined at a second point in time subsequent to the first point in time. At least one of a set of persistent differences and a set of transient differences is determined. The set of persistent differences includes a set intersection of the first and second sets of differences, the set intersection being filtered based on matching non-key values of the differences. The set of transient differences includes a relative complement of the second set of differences in the first set of differences.

Abstract: A data processing system and method of operation are disclosed. The data processing system includes a first site for processing data; a second site for processing data; and a transaction replay program configured to send a copy of data from the first site to the second site. A processor defines a maximum replication latency threshold and a reset threshold for the system, estimates a replication latency of a workload the system, switches the system to a first replication latency state when the estimated replication latency rises above the maximum replication latency and switches the system out of the first replication latency state to a second replication latency state when the estimated replication latency falls below the reset threshold.

Abstract: Embodiments of the disclosure are directed to methods, systems and computer program products for performing a planned workload switch. A method includes receiving a request to switch a site of an active workload and stopping one or more long running processes from submitting a new request to the active workload. The method also includes preventing a new network connection from accessing the active workload and processing one or more transactions in a queue of the active workload for a time period. Based on a determination that the queue of the active workload is not empty after the time period, the method includes aborting all remaining transactions in the queue of the active workload. The method further includes replicating all remaining committed units of work to a standby workload associated with the active workload.

Abstract: Systems for replication group partitioning include a workload profiling module configured to analyze historical workload data for a plurality of data elements to identify and categorize one or more transaction patterns; and a recommendation module configured to generate a recommended partitioning of the plurality of data elements into one or more replication groups, based on the one or more transaction patterns, that are optimized toward a partitioning goal.