Abstract: A central hub is coupled to a plurality of computational devices. The central hub stores a data structure that grants locks for accessing common data stored at the central hub, wherein the common data is shared by the plurality of computational devices. Each computational device maintains locally those locks that are held by the computational device in the data structure stored at the central hub. In response to a failure of the data structure stored at the central hub, a selected computational device of the plurality of computational devices is determined to be a manager system. Other computational devices besides the manager system communicate to the manager system all locks held by the other computational devices in the data structure stored at the central hub. The data structure and the common data are generated and stored at the manager system. Transactions are performed with respect to the data structure stored at the manager system, until the data structure stored at the central hub is operational.

Abstract: An apparatus, system, and method are disclosed for enqueue prioritization. The apparatus for enqueue prioritization is provided with a plurality of modules configured to functionally execute the steps of holding one or more queued requests in a queue, sorting the queued requests according to a first priority identifier associated with each of the queued requests, and assigning a second priority identifier to a delayed request in response to a determination that the delayed request has resided in the queue for a predetermined length of time, wherein the second priority identifier indicates a higher priority than the first priority identifier indicates. These modules in the described embodiments include a queue module, a sorting module, and a reassignment module.

Abstract: A method for data recovery of a data set migrated from a first storage media to a second storage media, where the data set includes a header record and multiple control records interleaved with corresponding data blocks. The header record is examined to identify a number of control records and data blocks comprising the data set. Next, the control records and data blocks are examined in order, starting with an initial data block, until a first data block is identified due to its failure to match the attribute included in the associated control record. Then the control records and data blocks are examined in reverse order, starting with a last data block, until a second data block is identified due to its failure to match an attribute included in the associated control record. Lastly, each data block from the first data block to the second data block are set to a lost data value.

Abstract: A plurality of data sets is maintained, wherein each data set comprises an index block and a plurality of data blocks. An index block size is determined for redefining the plurality of data sets, based on an amount of space left unused in index blocks of the plurality of data sets, wherein for determining the index block size greater weight is provided to those index blocks with lesser unused space in comparison to those index blocks with greater unused space. A data block size is determined based on whether the plurality of data blocks is used more frequently for direct processing or used more frequently for sequential processing.

Abstract: Method, system, and computer program product embodiments for performing a branch trace operation on a computer system of an end user are provided. An encrypted mapping macro is provided to the end user to be made operational on the computer system. A trace program is provided to the end user. The end user executes the trace program on the computer system as a diagnostic tool. The trace program is adapted for decrypting the encrypted mapping macro, determining a storage offset location of a branch instruction; checking the storage offset location for an identifying constant, cross referencing the identifying constant with an entry in the decrypted mapping macro to identify a branch triggering bit and diagnostic information associated with the branch instruction, and returning the branch triggering bit and diagnostic information, the branch triggering bit and diagnostic information provided to a coder.

Abstract: A method, system, and computer program product for performing a backup operation in a computing environment is provided. A list of keys identifying a plurality of locked records is created at a start of the backup operation. If a first locked record of the plurality of locked records is obtained during the backup operation, a first key identifying the first locked record is added to the list of keys. At a completion of the backup operation, if a second locked record of the plurality of locked records was not moved during the backup operation, a second key identifying the second locked record from the list of keys is dropped. The list of keys is written to a log file as in-flight updates. The in-flight updates are reprocessed through the backup operation using the log file.

Abstract: An apparatus, system, and method are disclosed for multi-address space tracing. A trigger module establishes a trigger event with a trace level. The trigger event occurs in at least a first address space of a plurality of address spaces. The trace level defines trace data to be stored from the plurality of address spaces. A monitor monitors messages communicated within and between the plurality of address spaces. A detection module detects the trigger event. A log module logs the trace data from the plurality of address spaces defined by the trace level in response to detecting the trigger event.

Abstract: An apparatus, system, and method are disclosed for dynamically allocating buffers during the execution of a job. A plan module sets a buffer allocation plan for the job using data access history that contains information about the number and nature of data access events in past executions of the same job. A buffer module allocates buffers during the execution of the job, and alters the buffer allocation to improve performance for direct access events for those portions of the job that the buffer allocation plan indicates have historically included predominantly direct access events. The buffer module alters the buffer allocation to improve performance for sequential access events for those portions of the job that the buffer allocation plan indicates have historically included predominantly sequential access events. A history module then collects data access information about the current execution and adds that information to the data access history.

Abstract: A method of minimizing data storage medium fragmentation, wherein the method provides a data storage library comprising (N) data storage media, wherein (N) is greater than or equal to 1. The method establishes a threshold fragmentation index, and determines, for each value of (i), an actual fragmentation index for an (i)th data storage medium, wherein (i) is greater than or equal to 1 and less than or equal to (N). The method receives a data set from a host computer in communication with the data storage library, and writes the data set to an (i)th data storage medium based upon an (i)th actual fragmentation index.

Abstract: A method for data recovery of a data set migrated from a first storage media to a second storage media, where the data set includes a header record and multiple control records interleaved with corresponding data blocks. The header record is examined to identify a number of control records and data blocks comprising the data set. Next, the control records and data blocks are examined in order, starting with an initial data block, until a first data block is identified due to its failure to match the attribute included in the associated control record. Then the control records and data blocks are examined in reverse order, starting with a last data block, until a second data block is identified due to its failure to match an attribute included in the associated control record. Lastly, each data block from the first data block to the second data block are set to a lost data value.

Abstract: An apparatus, system, and method are disclosed for analyzing code paths. In one embodiment, a starting point for one or more code paths within a listing of code is specified. The starting point may include code from which one or more code paths flow. An ending point is also specified for one or more code paths within the code, wherein the ending point includes code that is reachable via one or more of the code paths flowing from the starting point. Each code path flowing from the starting point to the ending point is determined by analyzing the listing of code without execution of the code. Information about the determined code paths is provided to a user.

Abstract: An apparatus, system, and method are disclosed for dynamically allocating buffers during the execution of a job. A plan module sets a buffer allocation plan for the job using data access history that contains information about the number and nature of data access events in past executions of the same job. A buffer module allocates buffers during the execution of the job, and alters the buffer allocation to improve performance for direct access events for those portions of the job that the buffer allocation plan indicates have historically included predominantly direct access events. The buffer module alters the buffer allocation to improve performance for sequential access events for those portions of the job that the buffer allocation plan indicates have historically included predominantly sequential access events. A history module then collects data access information about the current execution and adds that information to the data access history.

Abstract: Provided are a method, system, and program for allocating data sets to a container data set. A container data set is allocated in a storage system. An entry is included in a file allocation catalog for the allocated container data set indicating an address range of data allocated to the container data set, wherein the file allocation catalog maps data sets to address ranges in the storage system. A virtual file allocation catalog for the container data set is generated. A request is received to allocate a data set. A determination is made as to whether the data set to allocate has a size less than a threshold size. An entry is included in the virtual file allocation catalog to allocate the data set in the address range of the container data set in response to determining that the data set to allocate size is less than the threshold size.

Abstract: Provided are a method, system, and article of manufacture to manage storage resources in a storage system. Requests by processing systems are received for access to a control block providing information on an address assigned to one of the storage resources to access. A token is generated for each processing system requesting the control block uniquely identifying the processing system and the control block. The processing systems are provided copies of the requested control blocks to use to access the storage resource. A request is received to modify one of the control blocks for one of the storage resources. A determination is made as to whether at least one of the tokens was generated for the control block to modify. At least one processing system associated with the determined at least one token is provided a copy of the modified control block to use to access the storage resource associated with the control block.

Abstract: An apparatus, system, and method are disclosed for modifying data set names. A communication module receives a data set name as an index of a catalog entry for a catalog. The data set name comprises at least two qualifiers. A modification module modifies at least one data set name qualifier using a naming algorithm, wherein an alias qualifier is not modified. A store module stores the catalog entry indexed with the modified data set name in order to optimize the location of that entry within the catalog.

Abstract: Data is added to a data set to cause a growth in size of the data set, wherein the data set belongs to a storage group, and wherein the data set is comprised of extents. The data set is included into a new storage group, in response to determining that the growth in the size of the data set has caused a predetermined threshold for a size limit of the storage group to be exceeded. The extents of the data set are restructured to satisfy a predetermined condition on the extents of the data set, in response to determining that the growth in the size of the data set has caused the predetermined condition on the extents included in the data set to be not satisfied.

Abstract: Various embodiments for failure recovery in a computing environment following a data restoration are provided. A catalog locate is performed for each of a plurality of data sets on a base catalog structure (BCS), identifying a plurality of BCS entries. If a first BCS entry is cataloged incorrectly, the first BCS entry is designated to be re-cataloged. The plurality of BCS entries is compared with a plurality of volume table of contents and a plurality of VSAM volume data set (VTOC/VVDS) entries. If a second BCS entry found in the plurality of BCS entries is not found in the plurality of VTOC/VVDS entries, and the second BCS entry indicates that a data set associated with the second BCS entry is located on a volume, an attempt is made to vary on the volume. If the volume cannot be varied on, a request is created to restore the volume.

Abstract: A plurality of catalogs are maintained, and wherein each catalog of the plurality of catalogs includes data sets and attributes of the data sets. An indication that a new data set is to be defined is received. A selected catalog is determined from the plurality of catalogs, wherein the selected catalog is suitable for including the new data set and attributes of the new data set. An entry that indicates a data set name corresponding to the new data set and an index to the selected catalog is inserted in a group table.

Abstract: A method, system, and computer program product for identifying an overlay of a data processing target structure in a computing environment is provided. At least one of examining a mapping macro for the target structure with a set of valid ranges, comparing the set of valid ranges with the target structure to identify a string of at least one first invalid value and a last invalid value and locate invalid regions of the target structure, and examining executable code associated with the target structure, comparing at least one unchanged module against at least one additional module exhibiting an overlay characteristic to identify the string of the at least one first invalid value and the last invalid value and locate invalid regions of the target structure, is performed.

Abstract: Various embodiments for rapid defragmentation of storage volumes in a computing environment are provided. A plurality of source data sets is copied from the fragmented storage volume to a plurality of target data sets on an additional storage volume. The plurality of source data sets is placed on the additional storage volume as the plurality of target data sets in an unfragmented order. A first volume serial number (VOLSER) of the fragmented storage volume is swapped with a second VOLSER of the additional storage volume. The fragmented storage volume is varied offline, and the additional storage volume is varied online. The computing environment recognizes the additional storage volume having the plurality of target data sets placed in the unfragmented order.