developments in the common component architecture for

• CCA• Common Component Architecture

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,for the United States Department of Energy’s National Nuclear Security Administration

under contract DE-AC04-94AL85000.

Developments in the Common Component Architecture

for Scientific Software

Benjamin A. AllanCCA Forum

April 9, 2007


Overview

• Scalability in scientific software & components• Introduce CCA• Show applications and tools• The CCA specification

– Current state.– Items we expect for CCA 1.0.

• Community development• What could you do with CCA?


Human Minds Do Not Scale Well

Date

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man

age)

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10-1

10-2

Assemblers

Compilers

Structured Programming

Object-Oriented

Components

Practical high bound

108

We write imperfect

software

…but we must write more of it.


In Industry, Most Corporate Software is Component Software

Date

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are

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Components

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Components are for when complexity exceeds the power of a single human mind

Loose coupling and robust interfaces are more effective, including within single teams

Object-Oriented1980’s Object-oriented failed:1. Assumes a single language2. Implementation details

pollute the interfaces

1980’s Object-oriented failed:1. Assumes a single language2. Implementation details

pollute the interfaces

Components provide1. Code generation (stronger

interfaces & multiple languages)2. Additional runtime services to

support dynamic & loose coupling

Components provide1. Code generation (stronger

interfaces & multiple languages)2. Additional runtime services to

support dynamic & loose coupling


What is a component?

Interface definition language(IDL)

Fortran, C, C++,Java, Python Private code and data

Public interface(functions only)

Framework plug-in


What is a framework?

• A simple manager of component connections, &• A set of components specific to the application.


Code Reuse is NOT the Reason for Components

• Science and Research – Maintain correctness during many changes

• New students• New algorithms• New applications

• Corporate or for profit organization– Time to Market

Components provide strong interface boundaries & loose coupling (libraries do not).


Who and What is CCA?Our Goal:To provide an open forum defining multi-institutional, multi-disciplinary component architecture standards and tools enabling complex, maintainable, ultra-scale simulations through modern software practices and tools. Promote and support development of domain-specific common interfaces.

Approach: Multi-laboratory teams combine independent plug-&-play codes to create scalably engineered simulation systems.

Impact: Used in the USA and internationally for new science by scientists and educators in combustion, quantum chemistry, fusion, climate, astrophysics, fission reactor simulation, performance modeling & advanced solvers.

Institutions: ANL, JPL, LANL, LBNL, LLNL, NASA/Goddard,ORNL, PNNL, SUNY,Indiana U, U. Oregon,U. Utah,U. Illinois, Tech-X, …


What is most important about CCA?

Answer: Removing simulation code barriers in:– Programming languages– Hardware platforms– Organizations– Disciplines– Space– Time


Technically, what is CCA?

Common Component Architecture:

– Is Component-Based Software Engineering for HPC.

– Is specifications with neutrality in vendor, programming language, platform, network transport, and application.

– Avoids requirements that limit performance or shorten software life.


Distinctive technical features of CCA

• True object-oriented programming in FORTRAN or C.• Any-to-Any inter-language calling through SIDL. {C,

C++, Fortran[77,90,03], Java, Python}• Full support for multi-dimensional arrays in all

programming languages.• Remote method calls in all languages.• Light-weight frameworks.• Support for high performance platforms and Linux.


Any-to-any language binding

• Instead of pair-wise solutions:

• Write one wrapper to your library in the library’s language, and Babel does the other wrappers.

• Eliminates errors in and maintenance of language wrappers.

C++

f90

Python

C

f77

Java

C

C++

f77

f90

PythonJava


Remote method calls

• Calls between independent MPI jobs.– Example of sub-domain coupling later on.

• Calls between sensors and evolving simulations.

Cluster Sensor network


Where are CCA tools used?

Examples include:

• Quantum chemistry• Combustion• Material aging• Fission reactor simulation• Fusion processes• Performance measurement• More …


Example: Team of teams

PetSC

TAO

Python, C, C++, FORTRAN

MPI, ARMCI

Quantum chemistry optimization


Example: Performance profiling with a proxy Component

2Component

1

Component1

Component2

Proxy for Component

2

MasterMind TAU

Correlate function arguments and function costs-develop cost models and predict performance


Ex. Continued: Profiling Combustion

Automatically make proxy components with the

Tau profiling tools


Example: Multiscale vs Continuum Strain for Shock Wave on Metal Cylinder

Courtesy, Nathan Barton,LLNL.

Continuum OnlyMultiscale

• CCA• Common Component Architecture1 2 3 4 5 8760 9 n10ProcessorID

Fine Scale Response Compute Nodes

Ale3d

ResponseMaster

PSI Controller

PSI Daemons

The Petascale computer as collection of SPMD jobs (RMI+MPI)

= Process

= MPI_COMM_WORLD

= Babel RMI

Not shown: All processes can call Controller & Controller has a table of all MPI rank 0 processes.

Coupler

PSI Daemons

AdaptiveSampler

High-D Data Cache


What tools are available?

• SIDL and Babel• Portable parallel framework• Graphic application builder• Eclipse code editing and generator plug-ins• Scriptable tools (without graphic interface)


Composition tool: Ccaffeine


Advanced tools: Eclipse automation

• Eclipse


Automation features (a sampling)

• Eclipse:– SIDL/Babel plug-in for editing and building with Babel.– Generate SIDL and wrapper code by parsing C, C++,

FORTRAN, or Java.– Help for defining new components and interfaces.

• Command line (bocca):– Create custom stand-alone main programs from

components and scripts, making the framework just another library.


The CCA specification for HPC is:

• A standard component plug-in interface.– 1 function is required.– Components self-describe at run-time, optionally during

build time, to support the Uses-Provides pattern.• A source of interfaces for very basic services.

– Defining application interfaces is for domain experts.• Scalable (no communications required)• Written in Scientific IDL middleware (SIDL).


Basic services provided

• GoPort for starting a computation.• ParameterPort for run-time tuning.• Builder Service to create and manage peer

components in the same frame.• AbstractFramework containers to hold component

sub-sets.


Optional services provided

• MPI communicator access.• Performance data collection and logging.


What else is coming to CCA?

• More standard interfaces• More tools• More teams using CCA


Developing interface standards

• Parallel coupling interfaces.• Load balancing.• Workflow management (Kepler integration).• Quality of service management.• GUIBuilder service.


Developing tools (not yet public)

• C-only and FORTRAN-only frameworks (CCA-Lite).• Command line integrated development

environment (IDE) and portable build system • More Eclipse features.• High-performance communications layers for Babel

RMI.• CORBA communication layer for Babel RMI.• Wide-area network frameworks using Web

Services.


Developing teams

• Multi-institution software testing (each night building, testing, and reporting).

• TASCS project to provide infrastructure.• ITAPS project defining interfaces for parallel

unstructured mesh interconnections.• CSWIM (fusion simulation) coupling

magnetohydrodynamics, RF heating (ITER related).• TOPS, TAO solvers (linear, nonlinear, optimization)• Quantum chemistry, SAMR grids, many other areas.


What can you do with CCA and SIDL/Babel?

• Build loosely or strongly coupled applications that are more easily maintained and extended

• Write the main application in F90 (or any language you like)

• Call sub-applications remotely or in the same process• Call directly from F90 to C/C++/Python/Java without

writing any inter-language code manually• Donate improvements (all CCA tools are open-

source)


What we cannot do with CCA & Babel (today)

• Run on vector machines and in operating systems where the software has not been ported.– We port for anyone who donates test time and accounts.

• Develop in MS Windows– Windows is not critical to most US/DOE applications. – Adding Windows support requires a driving customer but is

technically simple. We accept Windows code donations.• Write your application main in Ruby or Matlab.

– Ruby should be easy to add.– Which Matlab version?

• Quad precision data outside Fortran.


The End

www.cca-forum.org/specification

www.cca-forum.org/tutorial

www.llnl.gov/casc/components/babel.html

Please join the fun:

[email protected]

https://www.cca-forum.org/wiki


On F90 from the ACTS 2006 CCA Tutorial1

Example Simple Numeric Integration Rule Component file:///C:/Documents%20and%20Settings/Administrator/Desktop/guide-html-

0.4.1_rc1/ch04s05.html#task2:integrator-mod

Object-oriented F90 Features:Private data for classes and class instances.Calling python/c/c++ subroutines just as F90 subroutines.Exception handling.Inheritance from other classes and even languages.

1) Chapter 4, section 5 http://www.cca-forum.org/download/tutorial/guide-html-0.4.1_rc1/ch04s05.html