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Siege was used as part of the 2006 Unidata Workshop. For more details see the report submitted to the American Meteorological Society.
Planned Extension and Modifications
The current version of Siege requires an intimate understanding of the inner workings of Siege, PWE, and the backend HPCs that the workflows will execute upon. This proposal calls for a far more user friendly user interface that must hide the complexity of the underlying system while not limiting access to the extensive capabilities provided.
The desktop version will be rewritten based upon the Bard toolkit as described above. A new product, Bard HPC, will be created with Siege as the initial desktop client. Common features of Bard HPC may also be used to create a web based job submission and monitoring interface.
Digital Synthesis Framework (DSF)
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The Digital Synthesis Framework (DSF) provides a coherent framework for dynamically publishing visual analysis environments based on underlying observational and modeled information. The concept of a synthesis framework involves core capabilities for integrating data from multiple sources, enabling on-demand execution of scientific workflows, and the association of data outputs with multiple visualization and analysis widgets in a dynamically generated web application. In the DSF, NCSA's Cyberintegrator workflow environment is used to integrate data sources and invoke modeling modules. When the workflow is complete, it can be saved and run repeatedly as a service. A publication service allows the workflow outputs (which may be observational data or model outputs) to be associated with visualization widgets and embedded into a dynamically generated scenario viewer web application. The application can display data outputs from completed workflows or can trigger new workflows on demand. Along with maps, graphs, tables, and other displays, the application can display provenance information and links to associated reference material. As a concrete example, we present one of the TRECC pilot projects to incorporate a model predicting hypoxic (low oxygen) conditions in Corpus Christi Bay, Texas based on information from sensors deployed in and around the bay, into a hypoxia forecast web application \[4]. |
Service Layer
Parameterized Workflow Engine (PWE)
The PWE is a workflow management system that has been incrementally developed over a period of eight years supporting high-performance applications in meteorology, chemical engineering, astronomy and even the analysis of financial markets. The entire process, while lengthy, has had a consistent set of goals.
- To assemble a loosely coupled set of components with well-defined functions such that we could extend them or compose into them other components as the need arose;
- To build an infrastructure above the lower middleware layer which would be general enough to suit a wide range of applications and not be tightly bound to the requirements of any single domain (along with this goal goes, needless to say, the requirement that application-level code remain insulated from this infrastructure; that is, that it need not be recompiled to work in our environment);
- o place high priority on productive and efficient interaction with the resource disposition typical of HPC centers, which more specifically means traditional batch queue managers; hence we have imposed a fundamental asynchronicity on the manner in which the highest level of the execution process must be handled (for instance, it would not make sense in this light that the component responsible for the execution logic hold the entire graph in memory for the duration of the workflow);
- To interact with existing resources such as mass storage systems and HPCs while requiring no modifications, additions, or installations on the remote resources.
Data Management
Metadata Management
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