1 A Component-based Framework for Uniform Resource Visualization Kukjin Lee Department of Computer Science & Engineering Michigan State University East Lansing, MI 48824 Phone:(517) 355-9974 Email: leekukji@cse.msu.edu Diane T. Rover Department of Electrical & Computer Engineering Michigan State University East Lansing, MI 48824 Phone: (517) 353-7735 Fax: (517) 353-1980 Email: rover@egr.msu.edu Keywords : resource monitoring, performance visualization, component-based development, visualization composition, uniform representation 1 Introduction The PGRT project has prototyped a framework for integrating performance analysis tools for parallel and distributed systems and for visualizing system and application performance [7]. One result of PGRT is a component-based specification language called the Visual Object Markup Language (VOML) [4][5][6]. VOML is an SGML-based language for specifying on-line performance visualization components. The framework includes two key features that support an integrated environment for performance problem solving: (1) portability across platform- dependent user interface toolkits, and (2) a flexible component-based visualization architecture, EPIRA (Event Processing and Information Rendering Architecture). Furthermore, the framework is object-oriented and easily distributable via middleware software such as CORBA and DCOM. VOML is based on two visual-object levels: a device-dependent low level, and a device- independent high-level. VOML uses SGML for structuring visual objects, and Scheme language scripts for defining performance visualization semantics. The use of SGML enables development of a performance visualization infrastructure, from which a designer may construct platform- and tool-independent visual objects. It may also facilitate automatic monitoring, analysis, and visualization of wide-area distributed applications via network-enabled SGML entity managers. The use of Scheme for visual object semantics enables both rapid prototyping of visual objects and customizing of VOs for a wide range of platforms. The Uniform Resource Visualization (URV) project, leveraging PGRT outcomes, has introduced a new paradigm for constructing visualizations and for monitoring and viewing complex parallel/distributed systems [8]. URV supports: (1) standard visualization services; (2) creation of system-level views through composition; and (3) sharing of visualization design knowledge. Uniformity in URV is implemented by describing resource and visualization components with XML-based formal descriptors. This facility helps developers to design uniform interfaces for accessing, viewing, and managing heterogeneous resources. Composition refers to support for multi-resource visualization. With the composition facility, the designer can construct a computational system with multiple resources and view system-level performance across resources. Reusability in URV is provided via descriptor registry and discovery. Using a directory service, users can retrieve existing visualizations, and by composing them, can construct a new visualization. Distinctive services of URV include: (1) metadata service to define visualizations for any resource in the system, ranging from hardware devices to application software modules; (2) connection service to bind resource(s) to a visualization; and (3)