# Presentation: 097230

## Trilinos Strategic (and Tactical) Planning

- Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,for the United States Department of Energy under contract DE-AC04-94AL85000.

**Notes:**
Questions from audience

Can you use another matrix-vector multiply?
Are multivectors supported?
Are Petsc and Hypre available via TSF?
How does Trilinos differ from Petsc?

## Outline of Talk

- Strategic Goals.
- Future Trilinos Presentations.
- Decisions: Made, pending, emerging.
- Brainstorming.

## Trilinos Strategic Goals

**Scalable Computations:** As problem size and processor counts increase, the cost of the computation will remain nearly fixed.
**Hardened Computations:** Never fail unless problem essentially intractable, in which case we diagnose and inform the user why the problem fails and provide a reliable measure of error.
**Full Vertical Coverage:** Provide leading edge enabling technologies through the entire technical application software stack: from problem construction, solution, analysis to optimization.
**Grand Universal Interoperability:** All Trilinos packages will be interoperable, so that any combination of packages that makes sense algorithmically will be possible within Trilinos and with compatible external software.
**Universal Accessibility:** All Trilinos capabilities will be available to users of major computing environments: C++, Fortran, Python and the Web, and from the desktop to the latest scalable systems.
**Universal Solver RAS:** Trilinos will be:
- Integrated into every major application at Sandia (**Availability**).
- The leading edge hardened, efficient, scalable solution for each of these applications (**Reliability**).
- Easy to maintain and upgrade within the application environment (**Serviceability**).

- Algorithmic
- Goals

- Software
- Goals

## Trilinos Presentation Forums

- HPCSW Workshop Tutorial
- High Performance Computer Science Week (HPCSW)
- Successor to LACSI Symposium.
- March 31 – April 4, 2008, Denver.
- ACTS “Hands-on” Tutorial:
- Aug 19-21, 2008 (approximate).
- At Lawrence Berkeley Lab, Berkeley, CA, USA.
- Next Trilinos User Group Meeting:
- Proposal: Oct 21-23, 2008.
- Old LACSI Symposium week.
- At Sandia National Laboratories, Albuquerque, NM, USA.
- SciDAC Conference (tentative).
- July13-17, 2008.
- Seattle.
- SC2008 Tutorial?

## Decisions Made: Scope

- Trilinos scope is larger: capabilities, customers, platforms.
**Capabilities** key descriptors: When is a package appropriate for Trilinos?
- Embeddable, reusable, interoperable.
- Scientific/engineering.
- Not applications (but probably app components in the future).
- Others?
**Customers**:
- NNSA, DOE Office of Science.
- DoD, DHS, general WFO.
- Broader community.
**Platforms**:
- All Oses: Unix/Linux, Windows, Mac
- Standard command line, Visual Studio, Xcode.
- Goal: Downloadable self-extracting archives. Cmake is the ticket.

## Decisions Pending: Aggregation

- 40+ packages: Aggregation necessary in some way.
- Miller’s Law: 7 +/- 2.
- How to aggregate?
- Already some:
- Epetra_Operator/RowMatrix.
- Thyra operators evaluators.
- Stratimikos.
- How do we build on this?
- No reason to introduce hierarchy in repository.
- Aggregation in:
- Concept, documentation, packaging.
- Big question: What gets put together?
- Proposal: Start with Stratimikos-related packages?

## Decisions Emerging: TDD

- Rigor alternative?
- TDD Steps:
- Write the test.
- Test and prove it failed.
- Write code.
- Prove test passed.
- Test-driven development.
- How?
- Make test registration easier.
- Inspections: Higher priority.
- How do we facilitate?
**Actions: **
**Develop checklist for closing bug review:**
**Code review, confirm that test checked.**
**Second person signs off on bug.**
**Add item to release checklist asking if code was reviewed.**

## Decisions Emerging: Others

- Source management:
- Continue looking at options.
- M. Eldred brings up good arguments for SVN.
- Trilinos Advisory Group:
- Group of Trilinos technical stakeholders.
- Quarterly phone meetings.
- Communication of framework related issues.
- Meant to communicate and avoid misunderstandings:
- SIERRA BJAM decision.
- If TAG around, could have avoided a lot of confusing discussion.

## Risks: Infrastructure staffing

- Loss of (and risk of loss of) critical skill sets:
- Mike Phenow plans to leave at the end of January.
- Present staffing model for infrastructure is weak, unattractive.
- Staffing for support is less than 2 years ago (1.5 vs. 2), size of project much larger.
- Working toward a matrixed solution.
- ID’ed an additional role: scientific programmer.

## Brainstorming

- What’s missing from the vertical software stack?
- Goal: Build an application using Trilinos building blocks.
- Only the physics or similar is unique.
- Andy’s list.
- Tools for AtC interaction: Helgi Adelsteinssen,  RichL. Mike Parks, Greg Wagner, Kevin Long.
- Interaction with UQ efforts (John Red-Horse).
- Builds from an app perspective.
- Other topics?
- Performance and scalability:
- Can apps use Trilinos to get performance beyond previous capabilities?
- Performance benchmarks in apps.
- What are the drivers?