Project Title

Improving the Usability and Effectiveness of the ACTS Toolkit

Project Homepage

http://acts.nersc.gov

Participants

NERSC (Brent Milne, John Wu, Bill Saphir)

Objective

The goal of our project is to improve the effectiveness and usability of ACTS tools.

Some of our specific goals are to:

Approach

This ongoing project extends the role of NERSC to include special support of ACTS and other experimental software. The NERSC effort is concentrated in three areas.
  1. Technical support. NERSC facilitates the use of ACTS components by providing specialized consulting services for new and advanced users, providing documentation and training for ACTS components, identifying potential ACTS users and promoting ACTS tools where appropriate.
  2. Increased availability and stability. Where appropriate, NERSC will install and maintain current versions of ACTS components on NERSC platforms, porting when necessary.
  3. Evaluation. NERSC evaluates the performance, robustness, functionality, and overall usability of ACTS components. NERSC then provides the evaluation results to users, so that they make informed choices, and to developers, so that they can improve the tools. As an independent third party to most of the tools, NERSC is in a position to provide "consumer reports" style information.
The NERSC effort takes on pro-active as well as advisory roles in its interactions with both users and developers. Actively working with application programmers to use toolkit components is critical to NERSC's ability to accurately judge tool effectiveness. Such work is also critical to our role in the cycle of tool development, use, feedback, and improvement. NERSC also seeks to work actively with developers to improve or extend tools to meet application and hardware specific needs that arise within the NERSC user community.

A key element in NERSC's advisory activities is its maintenance of a centralized ACTS information site on the World Wide Web. All information (documentation, evaluation, etc.) made available to NERSC users is placed on the Web so that it is accessible outside of NERSC. This includes information about how to obtain and install the software.

In a natural extension to these efforts, NERSC will also track continuing developments on toolkit wide infrastructure and interoperability efforts (such as those of the CCA and ESI groups) and provide input to these development groups to reflect the needs of the NERSC user community.

Accomplishments

Online ACTS Information Center

In August 1998, we unveiled the ACTS information center on the World Wide Web at http://acts.nersc.gov/. This site contains overviews, introductory information about each tool, preliminary evaluations, and instructions on where to get software and technical assistance.

Training

We have provided ACTS Toolkit tutorials at four separate NERSC user training sessions, at LBNL and remote sites.

Support

Four ACTS Tools are now officially installed and supported on the NERSC T3E - Aztec, PETSc, ScaLAPACK and TAU. Others are installed but have not been advanced to the level of "official support" including Global Arrays, Globus, POOMA, and PVODE.

Aztec, PETSc, and Tau have also been installed on the NERSC PC Cluster testbed, and will be part of a plug-and-play cluster environment distributed by NERSC to NERSC users and other researchers.

Applications

Intensive support has been provided in an effort to parallelize a legacy fluidized reactor bed code (MFIX) allowing the replacement custom serial components with components taken from the ACTS Toolkit (PETSc and Aztec). This work will result in a detailed evaluation and comparison of PETSc and Aztec. We are also investigating the possibility of using PVODE to replace the code's built-in stiff nonlinear integrator.

Additional direct support has been provided to current NERSC users of Aztec, CUMULVS, Globus and PETSc.

Prospective users of the ACTS Toolkit have been selected through a careful reading of all current ERCAP proposals, and these users have been sorted and categorized according to their potential for benefit from tool use. We have now begun to systematically contact these users in an attempt to encourage them to use the toolkit and to foster collaborations with our support effort.

Other efforts

We have worked directly with both the Globus development team and a group of NERSC users to evaluate the suitability of Globus to provide transparent remote access to the NERSC T3E. As part of this effort, ported the Globus gatekeeper to the NERSC T3E/Unicos production environment. A demonstration at the SC'98 demonstrated the possibility of using Globus to transparently start remote T3E jobs.

Responding to user interest, we investigated the CUMULVS tool and other issues (scheduling, security, machine management) related to remote steering and management of T3E jobs.

We have begun to participate in the Common Component Architecture (CCA) and Equation Solver Interface (ESI) groups. These efforts are likely to lead to the next generation of parallel tools, and will be the direct descendants of ACTS efforts.
 

Future Plans

Now that baseline support for ACTS tools has been established at NERSC, ongoing ACTS Toolkit support can be seen as two related but distinct activities. We plan to focus our in-depth support on a subset of tools and users, with an emphasis on support for the ("traditional") numerical style tools of the toolkit, and on support for the experimental technologies most likely to immediately impact NERSC applications, such as the ESI. In particular, NERSC plans to actively participate in both the eigenvalue and structured grid subgroups of the ESI group.

We would also like to work with the development teams of the more experimental tools to identify NERSC applications that could potentially benefit from the use of their tool, and to explore those benefits through active collaborations.

Should the CCA proceed with plans to develop a "real" prototypical application, we will seek also seek to paricipate in that effort.

In the next year we will also investigate improving user support in two new areas, both of which are expected to have strong ties to the ESI effort. The first is interfaces for the solution of eigenvalue problems, for which ACTS has no robust solutions. As potential ACTS users expect this functionality, we need to make sure we can provide it to them, and will investigate ways of doing this. The second is to look into creating a web-based sandbox for learning how to use ACTS tools and comparing different tools with similar capabilities. Since tool effectiveness is often application specific (e.g. for the solution of sparse systems, where there is a wide range of preconditioners and iterative solvers, and several ACTS tools that provide them) such a sandbox would allow users to make more informed decisions than we can enable through documentation and evaluation.

Tool Availability

Aztec, PETSc, ScaLAPACK and are available and officially supported on the NERSC T3E.