Focused Effort Title: Web Interfaces for Computational Modules

Thematic Area(s): Scalable Computing Migration, HPC Training and DoD User Productivity

PI Name: Dr. David Bernholdt (NPAC-Syracuse)

PI EMail Address: bernhold@npac.syr.edu

PI Telephone: (315) 443-3857 PI Fax: (315) 443-1973

Statement of Work: This effort has two parts -- a general framework applicable to all applications and a specific application effort applicable to FMS. There is a general need for launching large-grain computations from a simple web interface. Further, in many cases one later wishes to link these as modules in a larger computation where data flows between modules. This can be implemented using conventional Web Server technology (Java applets on clients connected to CGI scripts on servers), but even if this is appropriate today, developments in the object web suggest a powerful model that will fit in with CORBA, IMT/FMS trends to HLA, and increasing use of Java server technology. Syracuse will employ a strategy that allows such coarse-grain objects to be defined in a CORBA fashion on the server side with a Javabean applet front-end. This approach is language independent and will further fit with NPAC's WebFlow technology, which is designed precisely to tackle the dynamic coupling problems identified as critical in the Rice II PET meeting. WebFlow is being linked to the Globus metacomputing framework as part of an NSF sponsored NCSA effort and to CORBA through ARL FMS activity.

Initially, Syracuse will develop a methodology that handles individual modules with a general object framework. This involves:

a) Define a C CORBA wrapper suitable for typical scientific codes. It should have a "run" method, a "display" method (scientists may wish to preserve existing displays) and a set of getparm/setparm methods to find and set parameters. Other input and output methods should also be defined including those needed (eventually) for dataflow. Syracuse assumes C is the most useful language, as codes in FORTRAN can link to CORBA through C. Parallel computations are handled at this stage trivially by using "host-node" model and linking to the host. RIB-like "library" information should also be defined in a natural way.

b) Define a possible domain (FMS, chemistry, environmental quality, etc.) specific Javabean which initially is a container holding one such module at a time and can suitably access methods. It should allow the user to request which module is desired, so it needs to know all available modules. The Javabean and C wrapped module can be linked by JWORB or general public domain or commercial object brokers supporting C and Java bindings.

With future projects, Syracuse will:

c) Use the JORBed version of WebFlow to implement metacomputing

d) Use the Globus link with WebFlow to allow metacomputing with a visual interface.

e) Use a link to systems such as Nimrod (available in Globus) to control multiple program executions with different datasets

f) Note the natural link to CORBa like HLA, so this is a way of helping FMS users

g) Link to RIB as discussed in NHSE meetings

A CEWES FMS application will be the initial target for this project. The application will provide a single, comprehensive access to all application services, including a seamless access to DoD HPC resources. This web-based system will empower local and remote technology use, provide navigation aids for users with varying levels of familiarity with the system, and give access to remote data for browsing and visualization. This new system will be based on industry standard technologies and will reuse legacy as well as commodity software. Syracuse will implement a prototype system that, through a web interface, will allow execution of simulations on a geographically distributed system, including a local host. The front-end of the system will allow the user to specify computational resources to be used, location of the input data sets and the format of the output. The system will upload the specified data to the compute server and launch the application(s) there. The user will control the simulation using the original application's GUI displayed on his/her local display device, and if requested, the output will be feed to a local visualization engine.

Expenditure Profile: