Abstract: Embodiments of the present invention relate to methods, systems, and computer program products for event management. In a method, a plurality of notes that are comprised in a plurality of event records are obtained in a computer system. A plurality of paragraphs that are comprised in the plurality of notes are classified into a plurality of content types based on a content analysis of the plurality of paragraphs. The plurality of notes are classified into a plurality of semantic types based on the plurality of content types and a syntactic parsing to the plurality of notes. A knowledge item is generated for managing an event in the computer system based on a group of notes in the plurality of notes that are classified into the plurality of semantic types. With these embodiments, knowledge items for managing events may be obtained in an easier and more effective way.

Abstract: Embodiments of the present invention relate to methods, systems, and computer program products for event management. In a method, a plurality of notes that are comprised in a plurality of event records are obtained in a computer system. A plurality of paragraphs that are comprised in the plurality of notes are classified into a plurality of content types based on a content analysis of the plurality of paragraphs. The plurality of notes are classified into a plurality of semantic types based on the plurality of content types and a syntactic parsing to the plurality of notes. A knowledge item is generated for managing an event in the computer system based on a group of notes in the plurality of notes that are classified into the plurality of semantic types. With these embodiments, knowledge items for managing events may be obtained in an easier and more effective way.

Abstract: Embodiments of the present systems and methods may provide techniques for finding failing components in a distributed storage system. For example a method may comprise measuring problems and health of a plurality of physical and logical components in a distributed storage system, the plurality of physical and logical components forming nodes of the distributed storage system, and generating a graph of the nodes organized in a plurality of hierarchical levels, generating, for each node in the graph, a score summarizing the measured problems and health of the node, determining a highest score at a highest hierarchical level of the graph and determining the associated node as a failing component at a most significant level.

Abstract: A method, computerized apparatus and a computer program product for anomaly detection in a distributed system. The method comprises obtaining measurements of metrics of the distributed system within a timeframe. Each measurement comprises a time-series of values to a metric associated with an action of a component of the distributed system that was measured within the timeframe. A set of percentiles of the measurements is computed, whereby a dimensionality of the sets of percentiles is larger than a dimensionality of the metrics. A multivariate anomaly detection is performed based on the weights of the percentiles to determine an anomaly in the sets of percentiles. In response to detecting an anomaly, a source of the anomaly is identified based on a subset of the percentiles having weights above a threshold, by determining common components or actions that are common to at least a portion of the subset of the percentiles.

Abstract: A method, computerized apparatus and a computer program product for anomaly detection in a distributed system. The method comprises obtaining measurements of metrics of the distributed system within a timeframe. Each measurement comprises a time-series of values to a metric associated with an action of a component of the distributed system that was measured within the timeframe. A set of percentiles of the measurements is computed, whereby a dimensionality of the sets of percentiles is larger than a dimensionality of the metrics. A multivariate anomaly detection is performed based on the weights of the percentiles to determine an anomaly in the o sets of percentiles. In response to detecting an anomaly, a source of the anomaly is identified based on a subset of the percentiles having weights above a threshold, by determining common components or actions that are common to at least a portion of the subset of the percentiles.

Abstract: Embodiments of the present systems and methods may provide techniques for finding failing components in a distributed storage system. For example a method may comprise measuring problems and health of a plurality of physical and logical components in a distributed storage system, the plurality of physical and logical components forming nodes of the distributed storage system, and generating a graph of the nodes organized in a plurality of hierarchical levels, generating, for each node in the graph, a score summarizing the measured problems and health of the node, determining a highest score at a highest hierarchical level of the graph and determining the associated node as a failing component at a most significant level.

Abstract: The exemplary embodiments provide a computer implemented method, apparatus, and computer usable program code for managing memory. A suspect loitering object is detected for a set of selected applications, forming a detected object. The detected object is paged to persistent storage, forming a paged object. The paged object is deallocated from system memory, forming a deallocated object.

Abstract: A computer system provides an object-based virtual machine environment for running successive applications. The computer system includes storage, at least a portion of which is logically divided into two or more heaps in which objects can be stored. A first heap is reset between successive applications, and a second heap persists from one application to the next. A card table is provided which comprises multiple cards, each corresponding to a region of said storage. Each card in the card table is set to null when the first heap is reset between successive applications. A card is marked whenever an object in its corresponding storage region is created or updated. It is then possible to detect potential references from the second heap to the first heap at reset by scanning the cards in the card table corresponding to the second heap, and detecting any cards which have been marked. The system further identifies any objects on the first heap which have a finalization method.

Abstract: A computer system provides an object-based environment. The computer system includes storage. A contiguous linear portion of the storage is logically divided into first and second heaps located at opposite ends of the linear portion of storage. Any gap between the two heaps represents an unallocated region of storage. The system permits references from objects on the first heap to objects on the second heap and vice versa. A garbage collector operates across both heaps to remove objects that are no longer live. Means are provided for expanding the first and second heaps into the unallocated region. The first heap is expanded according to a first expansion policy, and the second heap is expanded according to a second expansion policy.

Abstract: This invention relates to memory management in a virtual machine or operating system and in particular to object creation and garbage collection. There is described a method and system of managing memory in a multi-threaded processing environment such as a java virtual machine comprising: creating an object in a thread heap; associating a status with the object and setting the status as local; using write barriers to change the status to global if the object is assigned to a static variable or if the object is assigned to a field in a global object; changing the status of all objects referenced by that object to global; and performing garbage collection by deleting from the thread heap, when memory space in the thread heap is required, one or more local objects which can not be traced to the thread stack.

Abstract: This invention relates to memory management in a virtual machine or operating system and in particular to object creation and garbage collection. There is described a method and system of managing memory in a multi-threaded processing environment such as a java virtual machine comprising: creating an object in a thread heap; associating a status with the object and setting the status as local; using write barriers to change the status to global if the object is assigned to a static variable or if the object is assigned to a field in any other object; and performing garbage collection by deleting from the thread heap, when memory space in the thread heap is required, one or more local objects which can not be traced to the thread stack.

Abstract: A computer system provides an object-based environment and includes storage. At least a portion of the storage is logically divided into two or more heaps in which objects can be stored. Each heap is subdivided into slices of memory. The system includes a two-level lookup structure for determining whether a given storage address corresponds to a particular heap. The lookup substructure involves a first level having one or more lookup substructures, each corresponding to a unit of memory representing a predetermined number of slices. The substructure indicates for each of these slices the particular heap, if any, that the slice belongs to. The two-level lookup structure further involves a second level for determining for a given memory address the first level lookup substructure that includes the slice containing that address.

Abstract: A method for memory management in execution of a program by a computer having a memory includes identifying in the program an array of array elements. At a given point in the program, a range of the elements is determined within the array such that none of the elements in the array outside the range is alive at the point. Information regarding the determined range is passed to a memory management function, so that memory locations are associated with the array elements, responsive to the determined range.

Abstract: Improved method of replication-based garbage collection in a multiprocessing system comprising a plurality of processors, a memory divided into a current area (from-space) used by the processors during current program execution and a reserved area (to-space), and at least a garbage collector for performing, when necessary, a garbage collection consisting in flipping the roles of the current area and reserved area after all the live objects stored in current area have been copied into the reserved area and for reclaiming the current area after the flipping operation. Several program threads (mutators) are currently running in parallel and the garbage collector performs the garbage collection in parallel with the program threads, the flipping operation being performed after the program threads have been stopped and the garbage collection has been completed.

Abstract: A computer system provides an object-based environment. The computer system includes storage. A contiguous linear portion of the storage is logically divided into first and second heaps located at opposite ends of the linear portion of storage. Any gap between the two heaps represents an unallocated region of storage. The system permits references from objects on the first heap to objects on the second heap and vice versa. A garbage collector operates across both heaps to remove objects that are no longer live. Means are provided for expanding the first and second heaps into the unallocated region. The first heap is expanded according to a first expansion policy, and the second heap is expanded according to a second expansion policy.

Abstract: A computer system provides an object-based virtual machine environment for running successive applications. The computer system includes storage, at least a portion of which is logically divided into two or more heaps in which objects can be stored. A first heap is reset between successive applications, and a second heap persists from one application to the next. A card table is provided which comprises multiple cards, each corresponding to a region of said storage. Each card in the card table is set to null when the first heap is reset between successive applications. A card is marked whenever an object in its corresponding storage region is created or updated. It is then possible to detect potential references from the second heap to the first heap at reset by scanning the cards in the card table corresponding to the second heap, and detecting any cards which have been marked.

Abstract: A computer system provides an object-based environment and includes storage. At least a portion of the storage is logically divided into two or more heaps in which objects can be stored. Each heap is subdivided into slices of memory. The system includes a two-level lookup structure for determining whether a given storage address corresponds to a particular heap. The lookup substructure involves a first level having one or more lookup substructures, each corresponding to a unit of memory representing a predetermined number of slices. The substructure indicates for each of these slices the particular heap, if any, that the slice belongs to. The two-level lookup structure further involves a second level for determining for a given memory address the first level lookup substructure that includes the slice containing that address.

Abstract: A computer system, program product, and method of collecting interned data utilize an interned indicator for an internable data element that indicates whether such a data element is in fact interned within an intern data structure. By maintaining this information, iteration completely through the intern data structure during collection may be avoided, thereby reducing the overhead and improving the efficiency of the collection process. In addition, a computer system, program product, and method of collecting interned data may also determine during a second stage of a collection cycle whether an interned data element, which was determined to be unreachable during a first stage of the collection cycle, has subsequently been accessed through an intern data structure since the beginning of the first stage of the collection cycle.

Abstract: A computer system, program product, and method of managing weak references with a concurrent mark sweep collector inhibit access, while processing weak references, to only those weak references whose referenced objects have not yet been determined to be strongly-reachable (i.e., reachable other than through a weak reference) during a current collection cycle. As such, access to specific weak references during processing thereof by a concurrent mark sweep collector is selectively inhibited to ensure synchronization for all weak references without necessarily stopping the execution of all program threads that attempt to access such weak references while executing in a computer system, thereby minimizing the processing overhead of managing weak references and improving system performance.