Abstract: A technique for reducing reader overhead when referencing a shared data element while facilitating realtime-safe detection of a grace period for deferring destruction of the shared data element. The grace period is determined by a condition in which all readers that are capable of referencing the shared data element have reached a quiescent state subsequent to a request for a quiescent state. Common case local quiescent state tracking may be performed using only local per-reader state information for all readers that have not blocked while in a read-side critical section in which the data element is referenced. Uncommon case non-local quiescent state tracking may be performed using non-local multi-reader state information for all readers that have blocked while in their read-side critical section. The common case local quiescent state tracking requires less processing overhead than the uncommon case non-local quiescent state tracking.

Abstract: A welding alignment and spacing article is provided for forming a welding gap between two structures to be welded together. The article includes a body having first and second surfaces that are spaced from each other at a selected spacing distance to define a region of selected body thickness. The body is formed from a non-metallic degradable body material in the region that can be wholly or partially degraded by exposure to a degrading agent to reduce the body thickness. The degradable body material is sufficiently incompressible to be useable as a spacer that maintains a specified welding gap distance between the two structures to be welded.

Abstract: A cluster recovery and maintenance technique for a server cluster having plural nodes implementing a server tier in a client-server computing architecture. A first group of N active nodes each run a software stack comprising a cluster management tier and a cluster application tier that actively provides services on behalf of one or more client applications running in a client application tier on the clients. A second group of M spare nodes each run a software stack comprising a cluster management tier and a cluster application tier that does not actively provide client application services. First and second zones in the cluster are determined in response to an active node membership change involving one or more active nodes departing from or being added to the first group as a result of an active node failing or becoming unreachable or as a result of a maintenance operation involving an active node.

Abstract: An electrical panelboard enclosure includes a primary service panel configured to receive power from a main power source and an alternate power source, an alternate power source connector array, and a distribution panel that delivers main or alternate power to subsidiary load circuits. A service transfer switch unit includes a main power breaker and an alternate power breaker having mutually interlocked toggle switches for respectively activating/deactivating the main and alternate power. The panelboard enclosure further includes an arrangement in which the primary service panel, the distribution panel, the alternate power source connector array and the service transfer switch are part of an installable panelboard assembly that is mountable as a unit within the panelboard enclosure.

Abstract: A system, method and computer program product for optimizing a software system through scenario evaluation. In accordance with the disclosed technique, a request is received for evaluation of an operational scenario that operates over an environment that is a superset of existing system capabilities encompassing system features or parameters that are not available in the currently running system. A knowledge base is consulted to derive recommendations with respect to operating parameters that may be collected to evaluate the scenario, mechanisms for gathering data relating to the parameters, and data evaluator operations for deriving a data evaluation result based on the data gathering. The knowledge base is further consulted to determine a reconfiguration recommendation based on the result. Scenario evaluation is performed based on simulation of the reconfiguration recommendation using the data evaluation result to determine efficacy of the scenario.

Abstract: A technique for implementing policy-aware backup and restore capability in a tiered storage system. If a data set's contents are backed up from the tiered storage system to a backup storage system, metadata for the data set may also be backed up. Prior to the data set being restored from the backup storage system to the tiered storage system, the backed up metadata is restored and processed to determine a tier among the tiered storage pools to which the data set will be restored.

Abstract: A portable security alarm system including a movement detecting and signal transmitting member for mounting on or proximate to the object whose movement is to be detected, a signal receiving and alarm generating member for receiving a signal from the movement detecting and signal transmitting member and producing a security response, a remote control for actuating and deactuating the signal receiving and alarm generating member, an environmental monitoring member for sensing an environmental condition and providing a signal to the signal receiving and alarm generating member, a visual information gathering member for gathering visual information and providing a signal to the signal receiving and alarm generating member, an audio output member for receiving a signal from the signal receiving and alarm generating member and generating an audio output, and components for delivering a security notification to remote recipients. A security network that includes the alarm system is also disclosed.

Abstract: A portable security alarm system including a movement detecting and signal transmitting member for mounting on or proximate to the object whose movement is to be detected, a signal receiving and alarm generating member for receiving a signal from the movement detecting and signal transmitting member and producing a security response, a remote control for actuating and deactuating the signal receiving and alarm generating member, an environmental monitoring member for sensing an environmental condition and providing a signal to the signal receiving and alarm generating member, a visual information gathering member for gathering visual information and providing a signal to the signal receiving and alarm generating member, an audio output member for receiving a signal from the signal receiving and alarm generating member and generating an audio output, and components for delivering a security notification to remote recipients. A security network that includes the alarm system is also disclosed.

Abstract: A method, system and computer program product for visualizing memory fragmentation in a data processing system includes determining a mobility status of plural memory pages and generating a map display depicting the plural memory pages and the mobility status.

Abstract: A cluster recovery and maintenance technique for use in a server cluster having plural nodes implementing a server tier in a client-server computing architecture. A first group of N active nodes each run a software stack comprising a cluster management tier and a cluster application tier that actively provides services on behalf of client applications running in a client application tier. A second group of M spare nodes each run a software stack comprising a cluster management tier and a cluster application tier that does not actively provide services on behalf of client applications. First and second zones in the cluster are determined in response to an active node membership change involving active nodes departing from or being added to the first group as a result of an active node failing or becoming unreachable or as a result of a maintenance operation involving an active node.

Abstract: A technique for optimizing grace period detection in a uniprocessor environment. An update operation is performed on a data element that is shared with non-preemptible readers of the data element. A call is issued to a synchronous grace period detection method. The synchronous grace period detection method performs synchronous grace period detection and returns from the call if the data processing system implements a multi-processor environment at the time of the call. The synchronous grace period detection determines the end of a grace period in which the readers have passed through a quiescent state and cannot be maintaining references to the pre-update view of the shared data. The synchronous grace period detection method returns from the call without performing grace period detection if the data processing system implements a uniprocessor environment at the time of the call.

Abstract: A technique for reducing reader overhead when referencing a shared data element while facilitating realtime-safe detection of a grace period for deferring destruction of the shared data element. The grace period is determined by a condition in which all readers that are capable of referencing the shared data element have reached a quiescent state subsequent to a request for a quiescent state. Common case local quiescent state tracking may be performed using only local per-reader state information for all readers that have not blocked while in a read-side critical section in which the data element is referenced. Uncommon case non-local quiescent state tracking may be performed using non-local multi-reader state information for all readers that have blocked while in their read-side critical section. The common case local quiescent state tracking requires less processing overhead than the uncommon case non-local quiescent state tracking.

Abstract: An electrolysis cell is controlled for operation under varying electrical power supply conditions. A flow of feed stock to the cell includes an electrolysis reactant at a controlled concentration. A varying amount of electrical power is supplied to the cell to produce an electrolysis reaction that generates a first reaction product at a first side of the cell and a second reaction product at a second side of the cell. The reactant concentration is adjusted as the electrical power varies to substantially maintain the cell at its thermal neutral voltage during cell operation. The cell may be used in an electrolysis system powered by a renewable energy source with varying power output (e.g., wind, solar, etc.).

Abstract: Database partition monitoring and dynamic logical partition reconfiguration in support of an autonomic self-tunable database management system are provided by an automated monitor that monitors one or more resource parameters in a logical partition running a database application in a logically partitioned data processing host. The monitor initiates dynamic logical partition reconfiguration in the event that the parameters vary from predetermined parameter values. In particular, the monitor can initiate removal of resources if one of the resource parameters is being underutilized and initiate addition of resources if one of the resource parameters is being overutilized. The monitor can also calculate an amount of resources to be removed or added. The monitor can interact directly with a dynamic logical partition reconfiguration function of the data processing host or it can utilize an intelligent intermediary that listens for a partition reconfiguration suggestion from the monitor.

Abstract: A partitioned NUMA machine is managed to dynamically transform its partition layout state based on NUMA considerations. The NUMA machine includes two or more NUMA nodes that are operatively interconnected by one or more internodal communication links. Each node includes one or more CPUs and associated memory circuitry. Two or more logical partitions each comprise at a CPU and memory circuit allocation on at least one NUMA node. Each partition respectively runs at least one associated data processing application. The partitions are dynamically managed at runtime to transform the distributed data processing machine from a first partition layout state to a second partition layout state that is optimized for the data processing applications according to whether a given partition will most efficiently execute within a single NUMA node or by spanning across a node boundary. The optimization is based on access latency and bandwidth in the NUMA machine.

Abstract: A planar bidirectional tape head with planar read and write elements for reading and writing data on a magnetic recording tape includes a substrate, a tape bearing surface for engaging the magnetic tape, one or more write element arrays formed on the substrate, and one or more read element arrays formed on the substrate. The one or more write element arrays and the one or more read element arrays comprise plural thin film layers oriented in generally parallel relationship with the tape bearing surface.

Abstract: Just-in-time dynamic instrumentation of a running software system may be achieved by registering one or more instrumentation probe handlers in an inactive state wherein the probe handlers reside in a memory space associated with the software system but are not instrumented into the software system. The probe handlers may each have one or more probe handler tags representing categories to which the probe handlers have been assigned. Tag query requests are periodically received and processed in order to provide information to a caller about registered probe handlers associated with a probe handler tag specified in the tag query request. A probe handler activation request can be made by specifying a probe handler or a probe handler tag. The request can be processed by placing the specified probe handler, or probe handlers associated with the tag, in an active state. The software system thus becomes dynamically instrumented to execute the probe handler(s) as part of the software system's execution flow.

Abstract: A planar write module and a hybrid planar write-vertical read bidirectional tape head comprising the write module and one or more vertical read modules. The write module has a write module tape bearing surface for engaging the magnetic recording tape. Plural write elements in the write module each comprise plural thin film layers oriented in generally parallel planar relationship with the write module tape bearing surface. The write elements are arranged so that the transducing gaps (write gaps) of adjacent write elements are generally aligned in a direction that is transverse to a streaming direction of the magnetic recording tape. Each read module has a read module tape bearing surface for engaging the magnetic recording tape. Plural read elements in the one or more read modules each comprise plural thin film layers oriented in generally perpendicular relationship with the read module tape bearing surface.

Abstract: A system, method and computer program product for synchronizing updates to shared mutable data in a clustered data processing system. A data element update operation is performed at each node of the cluster while preserving a pre-update view of the shared mutable data, or an associated operational mode, on behalf of readers that may be utilizing the pre-update view. A request is made for detection of a grace period, and grace period detection processing is performed for detecting when the cluster-wide grace period has occurred. When it does, a deferred action associated with the update operation it taken, such as removal of a pre-update view of the data element or termination of an associated mode of operation.

Abstract: A technique for low-power detection of a grace period following a shared data element update operation that affects non-preemptible data readers. A grace period processing action is implemented that requires a processor that may be running a non-preemptible reader of the shared data element to pass through a quiescent state before further grace period processing can proceed. A power status of the processor is also determined. Further grace period processing may proceed without requiring the processor to pass through a quiescent state if the power status indicates that quiescent state processing by the processor is unnecessary.