International Business Machines Corporation

Douglas Michael Zobre

Andrew M Sica

Joseph W Gentile

Robert Vaughn Geiner

Jie Hou

Steven Jay Greenspan

Stephen Joseph Kinder

Harry M Yudenfriend

Eli M Dow

Gregory E McBride

Jeffrey Mark Nick

William Frank Micka

David Michael Shackelford

David B Petersen

Robert Miller, Jr

Ronald Maynard Kern

Thomas F Rankin

Nicholas R Jones

Larry Richard Perry

Erin M Farr

Harold Glen Slone

Tarun Chopra

Linda Djohan

A file with an exclusive serialization is allocated. The exclusive serialization associated with the newly allocated file is transformed into a shared serialization. The file with the shared serialization is allocated as shared resource for a multisystem environment.

Sharing files in a multisystem environment

Embodiments of the present invention provide systems, methods, and computer program products for managing requests for acquiring one or more resources in a computing environment. In one embodiment, successful acquisition of the one or more resources is determined. Embodiments of the present invention provide systems, methods, and computer program products for initiating a synchronous request to acquire the one or more resources, responsive to determining that the acquisition of the one or more resources is not successful.

Management of asynchronous and synchronous resource requests

Embodiments of the present invention provide methods, program products, and systems for reusing a duplex storage medium resource. Embodiments of the present invention can be used to transition between duplex media by determining that a prior transition from a first duplex storage media to a second duplex storage media is being performed and reinitializing the second duplex storage media to receive, for storage, duplex data transferred from the first duplex storage media. Embodiments of the present invention can be used to reduce potential collisions with naming conventions and reduce unwanted delay that results in forcing an offload by managing the recovery medium and keeping it available through policy based medium changes.

Reusing a duplexed storage resource

Managing requests for acquiring resources in a computing environment. A first request to acquire resources is received. Whether the resources have been pre-acquired is determined. If the resources have not been pre-acquired, a token registering interest of a first thread in the first request is subscribed to. If the acquisition of the resources is not successful, whether a prior synchronous request has been initiated by a thread for the first request is determined. If a prior synchronous request has not been initiated, a synchronous request is initiated to acquire the resources. If the resources have not been pre-acquired for a second received request, an interest is registered of a second thread in the first request using the token. If the acquisition of the one or more resources is successful, a thread is notified of the successful acquisition, and the interest of the second thread is unregistered in the first request.

A method for managing log messages in a system includes identifying a log message having a data value, filtering a first data value from a historical log record for a first interval, predicting whether any particular system events should occur when the first data value is filtered from a received log record and identifying the corresponding system events, initiating a second interval while filtering the first data value from a received log record, determining whether any non-predicted system events have occurred, and removing the filter for the first data value responsive to determining that a non-predicted system event has occurred.

Management of log data in a networked system

A method and computer program product for testing a system logger. Randomized input is provided into a logging facility and automated testing of the logging facility is performed in a multi-processing environment. Self-verification of data retrieved from the logging facility is performed to ensure no data loss occurs due to external system events or failures driven by a test tool. Real-time analysis of results received is performed by the test tool based on the randomized input into the logging facility. First failure data is captured and self-verification of results of a data recovery operation of the logging facility is performed in a disaster recovery scenario. Self-verification includes writing log blocks of random sizes to the log stream, iteratively forcing log data to be offloaded from primary storage to secondary storage, iteratively updating log stream attributes, and iteratively swapping duplexing modes.

Testing of a system logging facility using randomized input and iteratively changed log parameters

In a system including a host, a primary storage subsystem coupled to the host, a cache coupled to the host and separate from the primary storage system, a secondary storage subsystem, and a data mover coupling the primary and secondary storage systems, data is temporarily cached for future storage in the primary storage subsystem so as to preserve timestamp information and maintain data consistency for asynchronously mirroring the data at a secondary subsystem.

Adjusting timestamps to preserve update timing information for cached data objects

The frequency at which a multisystem log stream is compressed by a system of a multisystem environment is adjusted in real-time. The rate at which the multisystem log stream is compressed by the system is ascertained. That rate is relative to how frequently the multisystem log stream is compressed by other systems of the multisystem environment. The frequency with which the system compresses the multisystem log stream is then adjusted in real-time. Thus, the frequency at which one system of the multisystem environment compresses the log stream is relative to the frequency at which other systems of the multisystem environment are compressing the log stream.

Pacing the frequency at which systems of a multisystem environment compress log streams

Method of pacing the frequency at which systems of a multisystem environment compress log streams

Program products for pacing the frequency at which systems of a multisystem environment compress log streams

A system and method for providing two or more contending processes with concurrent access to a shared resource having a primary list of elements and a list access count, with direct association between at least first and second consecutive elements each having a use counter, wherein resource access includes an obligation to perform an access completion operation. The method comprises the steps of marking the first element as ready to be deleted upon receiving a signal from a traversing one of the contending processes. Next, the first element ready to be deleted is placed on a delete list, is unchained from the primary list and is moved the delete list to an unchained list. A determination is made whether the list access counter is equal to zero: if not, the list access counter is decremented and the system waits for another contending process to access the primary list; if so, an obligation is passed to the traversing process to perform an access completion operation by: determining whether the second element's use counter is equal to zero: if not, the list access counter is decremented and the system waits for another contending process to access the primary list; if so, the first element can be released thereby completing its deletion or it can be put a free list, thereby indicating that the first element is ready to be released. Once all elements are moved from the unchained list and placed on the free list, the free list can be released in its entirety.

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Poughkeepsie, NY, United States of America

Douglas Michael Zobre