International Business Machines Corporation

Thomas C Reed

David C Reed

Max D Smith

Derek Logan Erdmann

Dustin A Helak

Philip R Chauvet

Esteban Rios

Trevor A Geisler

Joseph V Malinowski

Eric J Harris

Kenneth J Owin

Franklin E Mccune

Provided are a computer program product, system, and method for a data set connection manager having a plurality of data sets to represent one data set. A request is processed to open a connection to a data set having members, wherein the connection is used to perform read and write requests to the members in the data set. In response to establishing the connection, establishing for the connection a primary data set having all the members; a secondary data set to which updated members in the primary data set are written; and a pending delete data set to pending delete members comprising members that are updated.

Data set connection manager having a plurality of data sets to represent one data set

A method for more effectively utilizing computing resources in a data replication environment is disclosed. In one embodiment, such a method detects, at a primary system, activity occurring on the primary system. This activity is recorded in systems logs located at the primary system. The method automatically mirrors the system logs from the primary system to a secondary system that is in a mirroring relationship with the primary system. The system logs are analyzed at the secondary system. In the event abnormal activity is detected in the system logs at the secondary system, the method automatically sends, from the secondary system to the primary system, one or more commands that are designed to address the abnormal activity. A corresponding system and computer program product are also disclosed.

Remote health monitoring in data replication environments

A method for enabling data set changes to be reverted to a prior point in time or state is disclosed. In one embodiment, such a method includes providing a data set comprising one or more data elements and a specified number of generations of the data elements. In certain embodiments, the data set is a partitioned data set extended (PDSE) data set, and the data elements are 'members' within the PDSE data set. The method further includes tracking changes made by a job to data elements of the data set. The method further references, in a data structure (also referred to herein as a 'cluster') associated with the job, previous generations of the data elements changed by the job. In certain embodiments, the data structure is stored in the data set. A corresponding system and computer program product are also disclosed.

PDSE member generation clustering and recovery

Provided are a computer program product, system, and method for generating node access information for a transaction accessing nodes of a data set index. Pages in the memory are allocated to internal nodes and leaf nodes of a tree data structure representing all or a portion of a data set index for the data set. A transaction is processed with respect to the data set that involves accessing the internal and leaf nodes in the tree data structure, wherein the transaction comprises a read or write operation. Node access information is generated in transaction information, for accessed nodes comprising nodes in the tree data structure accessed as part of processing the transaction. The node access information includes a pointer to the page allocated to the accessed node prior to the transaction in response to the node being modified during the transaction.

Generating node access information for a transaction accessing nodes of a data set index

A method for more effectively utilizing computing resources in a data replication environment is disclosed. In one embodiment, such a method detects, at a primary system, activity occurring on the primary system. This activity is recorded in systems logs located at the primary system. The method automatically mirrors the system logs from the primary system to a secondary system that is in a mirroring relationship with the primary system. The system logs are analyzed at the secondary system. In the event abnormal activity is detected in the system logs at the secondary system, the method identifies, on the secondary system, a data set that is associated with the abnormal activity. A snapshot is taken of this data set and saved on the secondary system for later analysis. A corresponding system and computer program product are also disclosed.

Remote data capture in data replication environments

A method for storing data includes establishing an extended generation group comprising a plurality of data sets. The plurality of data sets includes a first data set containing primary members and a first number of generations of each of the primary members, and a second data set containing a second number of generations of each of the primary members. The method further indicates, in the metadata of the first data set, a maximum number of generations allowable in each of the first and second data sets When a primary member is modified in the first data set, the method automatically moves an oldest generation in the first data set to the second data set, and deletes an oldest generation in the second data set to ensure that the extended generation group does not exceed the maximum number.

PDSE extended generation grouping for tiered storage systems

Provided are a computer program product, system, and method for managing multiple locks for data set members in a data set index. The data set index has leaf nodes and internal nodes. In response to determining that a current lock is set at a locked node that prevents a grant to a requested lock, a determination is made as to whether there are different first and second descendant nodes from the locked node at a same level of the tree data structure linked to the requested data set member and the locked data set member, respectively. If so, the requested lock for the requested data set member is set at the first descendant node, the current lock is moved to the second descendant node for the locked data set member and the requested lock is granted.

Managing multiple locks for data set members in a data set index

A method for retaining data pages in a cache is disclosed. In one embodiment, such a method stores multiple data pages in a cache. The method calculates, for each data page, a cost associated with promoting the data page from persistent storage media to the cache. The cost takes into account any data transformations (decryption, decompression, etc.) that are needed to promote the data page from the persistent storage media to the cache. In certain embodiments, the cost is represented as a score that is assigned to each data page. The method retains each data page in the cache for an amount of time that is related to its cost, such that data pages with a higher cost are retained in the cache longer than data pages with a lower cost. A corresponding apparatus and computer program product are also disclosed.

Cache page retention based on page cost

A method for performing a data dump includes detecting an error in a segmented application having an address space and a buffer. In response to detecting the error, the method quiesces the address space and copies content of the address space to another location while the address space is quiesced. The method reactivates the address space after the content of the address space is completely copied. The method suspends write access to the buffer and copies content of the buffer to another location while write access to the buffer is suspended. While write access to the buffer is suspended, the method redirects writes intended for the buffer to a temporary storage area, and directs reads intended for the buffer to one of the buffer and the temporary storage area, depending on where valid data is stored. A corresponding system and computer program product are also disclosed.

Minimally disruptive data capture for segmented applications

Methods that can parallel search a partitioned data set extended (PSDE) indexes are provided. One method includes managing a set of quick indexes in a memory device in which the set of quick indexes include references to storage locations for a subset of members of a PDSE stored in a set of long-term storage devices. The method further includes receiving a request to determine a storage location of a member of the PDSE and, in response to the request, searching the set of quick indexes to determine the storage location. Systems and computer program products for performing the above method are also provided.

Parallel search of a partitioned data set extended (PDSE) in parallel

Provided are a computer program product, system, and method for selecting pages implementing leaf nodes and internal nodes of a data set index for reuse in memory. Pages in the memory are allocated to internal nodes and leaf nodes of a tree data structure representing all or a portion of a data set index for the data set. At least at least one duration parameter indicates an amount of time after which an unused page implement one of the internal nodes or leaf nodes is eligible for reuse. Selection is made of at least one selected page allocated to at least one of the leaf nodes and the internal nodes that has not been used for one of the at least one duration parameter for reuse.

Selecting pages implementing leaf nodes and internal nodes of a data set index for reuse

Provided are a computer program product, system, and method for migrating jobs from a source server from which data is migrated to a target server to which the data is migrated. Mirrored data is copied from a source storage to a target storage. A determination is made of at least one eligible job of the jobs executing in the source server having execution characteristics indicating that the job is eligible for migration to the target server. The determined at least one eligible job is migrated to the target server to execute on the target server and perform operations with respect to the mirrored data in the target storage. The migrated eligible job is disabled at the source server.

Migrating jobs from a source server from which data is migrated to a target server to which the data is migrated

A new layer for runtime detection of vendor hooks, with respect to a program module, includes mapping of branching instructions and their respective targets. When the program module is compiled, branch instructions are mapped and recorded to generate one or more branch maps. A branch map includes target program module addresses (or associated respective placeholders) and respective instruction offsets. At runtime, placeholders are replaced with respective target program module addresses. At runtime, actual branching information is compared to branching information included in the branch map. If a discrepancy is detected between runtime branching information and the corresponding branching information recorded in the branch map, a responsive action is triggered.

Runtime detection of code modification

A computer-implemented method according to one embodiment includes intercepting one or more updates made to a catalog data set, storing the one or more updates in an update buffer, retrieving the one or more updates from the update buffer, sequentially applying the one or more updates to a backup catalog data set, identifying a request to replace the catalog data set, and replacing the catalog data set with the backup catalog data set, in response to the request.

Catalog backup and recovery using logical mirroring

Provided are a computer program product, system, and method to use data set copies for recovery of a data set in event of a failure. In response to an update to the data set, a determination is made of an update group to include at least one copy of the data set that was not in a last determined update group to which a previous update was applied and to exclude at least one copy of the data set that was in the last determined update group. The update to the data set is applied to the copies of the data set in the update group and not applied to the copies not in the update group. In response to a failure event, the data set is recovered from one of the copies of the data set in the update group or not in the update group.

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Tucson, AZ, United States of America

Thomas C Reed