Abstract: A video data and metadata storage and retrieval system including storage apparatus for storing a plurality of recorded video portions and metadata describing a plurality of geographical locations and corresponding times at which the video portions were recorded, and a computer configured to query the stored metadata, identify a plurality of the recorded video portions that correspond to the metadata resulting from the query, and group any of the identified video portions together into a video clip that are separated by less than a predefined clip gap.

Abstract: In a cluster of computing nodes having shared access to one or more file systems in data storage using parallel file system software, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system software by the user application on the second node to mount one of the file systems in the data storage. A mount event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node. When the file system is to be unmounted, preunmount and unmount events are sent for processing by the data management application on the first node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a session node selected from among the nodes in the cluster. The session node receives an event message in a session queue for processing by the data management application, responsive to a request submitted to the parallel file system by a source node among the nodes in the cluster to perform a file operation on a file in the data storage. Following a failure at the session node, the session queue is reconstructed so that processing of the event message by the data management application can continue after recovery from the failure, and the request can be fulfilled at the source node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system by the user application on the second node to perform a file operation on a file in one of the volumes of data storage. A data management event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system by the user application on the second node to perform a file operation on a file in one of the volumes of data storage. A data management event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node.

Abstract: In a cluster of computing nodes having shared access to one or more file systems in data storage using parallel file system software, a method for managing the data storage includes initiating a session of a data management application on a first one of the nodes, while running a user application on a second one of the nodes. A request is submitted to the parallel file system software by the user application on the second node to mount one of the file systems in the data storage. A mount event message is sent from the second node to the first node responsive to the request, for processing by the data management application on the first node. When the file system is to be unmounted, preunmount and unmount events are sent for processing by the data management application on the first node.

Abstract: In a cluster of computing nodes having shared access to one or more volumes of data storage using a parallel file system, a method for managing the data storage includes initiating a session of a data management application on a session node selected from among the nodes in the cluster. The session node receives an event message in a session queue for processing by the data management application, responsive to a request submitted to the parallel file system by a source node among the nodes in the cluster to perform a file operation on a file in the data storage. Following a failure at the session node, the session queue is reconstructed so that processing of the event message by the data management application can continue after recovery from the failure, and the request can be fulfilled at the source node.

Abstract: A system for garbage collection of memory objects in a memory heap. The system includes a memory heap that is partitioned into few generations, each generation being partitioned into cards. The generations are associated with remembered sets and card markings data structure. Each card in the card markings data structure includes scan generation related data that represent generations for which the card has or has not to be scanned. The system further includes a processor communicating with the memory for scanning the cards according to the scan generation related data, and in response to identifying updated inter-generational pointers, the processor is capable of updating the remember set with the identified inter-generational pointers. The processor is further capable of updating the scan generation related data.

Abstract: A system for garbage collection of memory objects in a memory heap. The system includes memory heap that is partitioned into respective old and young areas. The old area is partitioned into cars and is further associated with card markings and remembered sets data structures. The card markings include for each card, a card time stamp that represents the time that the card was updated. The car includes, for each car, a car time entry stamp that represents the time the remembered set of the car was updated. The system further includes a processor communicating with the memory, and being capable of identifying all cards that were updated later than the remembered set of a selected car. In response to the event, it performs identifying change in pointers that refer from the card to a memory object in the selected car and in response to identified change in pointers, updating the remembered set of the car with the identified pointers.

Abstract: In a computer application having a counter for setting first and second counter values in respect of first and second objects. The counter has a range of n possible values and being incremented or decremented in accordance with update criterion. The application taking an action according to whether the first counter value is larger or equal to the second counter value. A method for handling a courter overflow event whereby the counter is incremented beyond said range by executing the steps of: compacting the first and second counter values to m values (m<n) so as to constitute first and second compacted counter values, such that if the first counter value id larger than or equal to the second counter value then the compacted first value is not smaller than the compacted second value, and setting the counter to a value from among n-m values within the specified range.

Abstract: A method is described for operating a data processing system having a plurality of processors to sort a set of data records each having an associated key for governing the sort process. The method comprises determining a range for the key values by sampling the key values. The range is divided into a plurality of quantiles, one for each processor, each quantile having a respective index. At each processor, a plurality of buckets are defined, each bucket corresponding to a respective one of a plurality M.sub.p of subintervals in the quantile, each subinterval having a respective index. The index of the quantile in which the key value lies and the index of the subinterval in which the key value lies are determined directly from the key values using fast operations. Each key is distributed to the processor corresponding to the quantile in which the key value lies.

Abstract: A method is described for operating a computer to sort a set of data records each having an associated key for governing the sort process, the method comprising determining a range for the key values by sampling the key values; defining a plurality of buckets, each bucket corresponding to a respective one of a plurality M of subintervals in the range, and two edge buckets for key values outside the range, each subinterval having a respective index; distributing the keys among the buckets by determining directly from each key value the index of the subinterval into which the key value falls; and processing the buckets in sequence in order to sort the records, sorting the keys in each bucket if the bucket contains more than one key.