Abstract: Exemplary systems and methods for visualization of data analysis are provided. In various embodiments, a method comprises accessing a database, analyzing the database to identify clusters of data, generating an interactive visualization comprising a plurality of nodes and a plurality of edges wherein a first node of the plurality of nodes represents a cluster and an edge of the plurality of edges represents an intersection of nodes of the plurality of nodes, selecting and dragging the first node in response to a user action, and reorienting the interactive visualization in response to the user action of selecting and dragging the first node.

Abstract: In some embodiments, a method comprises selecting a first and a second predetermined number of points of graphical data; determining an initial distance between each of the first predetermined number of points, generating a fast approximate distance oracle comprising identifiers of points and oracle distances between at least one point and another point, determining a graphical distance for each of the second predetermined number of points relative to other points of the first and second predetermined number of points, calculating a potential error between the determined graphical distance and a topologic distance between each of the second predetermined number of points, approximating a correction for at least one of the second predetermined number of points, adjusting a position of the at least one of the second predetermined number of points, and displaying the at least one of the second predetermined number of points.

Abstract: Exemplary systems and methods for visualization of data analysis are provided. In various embodiments, a method comprises accessing a database, analyzing the database to identify clusters of data, generating an interactive visualization comprising a plurality of nodes and a plurality of edges wherein a first node of the plurality of nodes represents a cluster and an edge of the plurality of edges represents an intersection of nodes of the plurality of nodes, selecting and dragging the first node in response to a user action, and reorienting the interactive visualization in response to the user action of selecting and dragging the first node.

Abstract: Techniques for memory management or analysis with conservative garbage collectors is provided. The native stack is analyzed during runtime to identify within frames references to objects in the heap space. An amount of memory is calculated that represents the memory implicated by the reference. A log can be generated that conveys the frame, location of the reference in the frame and amount of memory implicated by the reference.

Abstract: Techniques are provided for instantiating separate Java virtual machines for each session established by a server. Because each session has its own virtual machine, the Java programs executed by the server for each user connected to the server are insulated from the Java programs executed by the server for all other users connected to the server. The separate VM instances can be created and run, for example, in separate units of execution that are managed by the operating system of the platform on which the server is executing. For example, the separate VM instances may be executed either as separate processes, or using separate system threads. Because the units of execution used to run the separate VM instances are provided by the operating system, the operating system is able to ensure that the appropriate degree of insulation exists between the VM instances.

Abstract: A method of managing memory mapped input/output (I/O) for a run-time environment is disclosed, in which opaque references are used for accessing information blocks included in files used in a dynamic run-time environment. The information block is stored in a shared memory space of pages that are each aligned on respective boundaries having addresses that are each some multiple of two raised to an integer power. The opaque reference used for the dynamic run-time environment includes at least an index, or page number reference into a page map of references to the pages of the shared memory space, and an offset value indicating an offset into the referenced page for the beginning of the storage of the information block. Control bits of the opaque reference indicate information such as the mapping mode, e.g., read-only, read-write, or private. Pages which are modified by a process may be written back to a backing store of the file based on control bits which indicate that a page has been modified.

Abstract: A method and software for managing class variables is described in which a variable-format container for static class variables is provided such that numeric class variables can be accessed directly while other kinds of class variables are accessed via a reference to an object.

Abstract: A heap analyzer that processes a snapshot of the heap contained in a dump file is described. The heap analyzer tool can be configured to relocate the pointers in the dumped heap and allow developers to examine the heap in web browser by presenting markup for displaying a heap object in the browser and rendering pointers in the object as clickable links. When a link is selected, the pointer is followed to another object and markup is generated for rendering that object with its links. Furthermore, callbacks may be provided through an application programming interface (API) to allow developers to furnish their own code for analyzing and displaying their data structures.

Abstract: A method for scanning objects as for garbage collection is described that employ an ancillary data structure to describe the format of an object. Specifically, the data structure lists which parts of the object are references and how large each part of the object is. Scanning the object can efficiently occur by stepping through the object and the data structure in parallel.

Abstract: A method and software for analyzing a heap is described, in which a snapshot is made of a heap, which can be later analyzed by an analysis tool when a program that had run out of memory is no longer running. In one embodiment, an object allocated by the program is accessed and copied into a file, and an address of the object allocated by the process is recorded in association with an offset in the file of the copy of the object. The copy of the object copied into the file has preferably the same size as the object allocated by the process. A heap analysis tool may then be run on the objects copied into the file.

Abstract: A method and software for managing pointers to external objects in a run-time environment are described in which eager external references are provided that allow session memory objects to point directly to certain call memory objects with machine pointers. The eager external references contain enough information to recreate the call memory objects in call memory at the beginning of the call and fix the session memory objects to point to the new locations of the recreated call memory objects.

Abstract: A computer-implemented method and software are provided for supporting a platform independent object format for a run-time environment in which a definition of an object in terms of a composition of one or more primitive types and a platform-specific description of the one or more primitive types are accessed. A layout for the object is then generated in a high-order language based on the definition of the object and the platform-specific description.

Abstract: Techniques for memory management or analysis with conservative garbage collectors is provided. The native stack is analyzed during runtime to identify within frames references to objects in the heap space. An amount of memory is calculated that represents the memory implicated by the reference. A log can be generated that conveys the frame, location of the reference in the frame and amount of memory implicated by the reference.

Abstract: Techniques are provided for accessing an instance of a recreatable object in a shorter-duration memory based on a reference located in a longer-duration memory, where the shorter-duration memory is associated with a call. One technique involves (1) locating, within the shorter-duration memory, a context structure associated with the call; (2) locating an XREF pointers array based on data cached within the context structure; (3) determining whether the XREF pointers array includes a pointer associated with the reference; and (4) if the XREF pointers array includes a pointer associated with the reference, then following the pointer to locate the instance within the shorter-duration memory.

Abstract: A method and software for performing data migration is described in which a common data migration driver routine is provided to handle various and disparate kinds of migration operations in a conceptually unified manner. Differences between the migration operations are handled by variations in how the state of the data migration driver routine is initialized, including pointers to low-level routines. Furthermore, a table of actions can be used to direct the basic operation of object copying, external reference created, and object interning.

Abstract: A memory model for a run-time environment is disclosed that includes a process-specific area of memory where objects in call-specific area of memory and session-specific area of memory can be migrated to at the end of a database call. User-specific objects can be then migrated to the session-specific area of memory. In one embodiment, the process-specific area of memory can be saved in a disk file and used to hot start another instance of an application server.

Abstract: A heap analyzer that processes a snapshot of the heap contained in a dump file is described. The heap analyzer tool can be configured to relocate the pointers in the dumped heap and allow developers to examine the heap in web browser by presenting markup for displaying a heap object in the browser and rendering pointers in the object as clickable links. When a link is selected, the pointer is followed to another object and markup is generated for rendering that object with its links. Furthermore, callbacks may be provided through an application programming interface (API) to allow developers to furnish their own code for analyzing and displaying their data structures.

Abstract: A method of managing memory mapped input/output (I/O) for a run-time environment is disclosed, in which opaque references are used for accessing information blocks included in files used in a dynamic run-time environment. The information block is stored in a shared memory space of pages that are each aligned on respective boundaries having addresses that are each some multiple of two raised to an integer power. The opaque reference used for the dynamic run-time environment includes at least an index, or page number reference into a page map of references to the pages of the shared memory space, and an offset value indicating an offset into the referenced page for the beginning of the storage of the information block. Control bits of the opaque reference indicate information such as the mapping mode, e.g., read-only, read-write, or private. Pages which are modified by a process may be written back to a backing store of the file based on control bits which indicate that a page has been modified.

Abstract: A method and software for analyzing a heap is described, in which a snapshot is made of a heap, which can be later analyzed by an analysis tool when a program that had run out of memory is no longer running. In one embodiment, an object allocated by the program is accessed and copied into a file, and an address of the object allocated by the process is recorded in association with an offset in the file of the copy of the object. The copy of the object copied into the file has preferably the same size as the object allocated by the process. A heap analysis tool may then be run on the objects copied into the file.

Abstract: Backtraces are logged in the log file during execution of a program and tagged with information that can categorize the backtraces. Certain tags are also marked as “interesting” in the log file. A report is generated from the log file, indicating which of the backtraces are associated with the tags marked as interesting. In one embodiment, allocations of objects are logged with their addresses, and the objects that are later migrated into session memory are marked interesting.