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Libraries for Clustered Computing and a few other things . Anne E. Trefethen NAG Ltd, Oxford. What is NAG?. Mishi Derakhshan Nadir Bouhamou Vince Fernando Arnold Krommer. Stefano Salvini Lawrence Mulholland Sven Hammarling Jeremy DuCroz Ken McDonald. Acknowledgements.
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Libraries for Clustered Computingand a few other things... Anne E. Trefethen NAG Ltd, Oxford
What is NAG? Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Mishi Derakhshan Nadir Bouhamou Vince Fernando Arnold Krommer Stefano Salvini Lawrence Mulholland Sven Hammarling Jeremy DuCroz Ken McDonald Acknowledgements The ScaLAPACK team Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Involvement in High Performance Computing Anne E. Trefethen Workshop on Clusters, Blackberry Farm
A Couple of General Points • Important to NAG that libraries are portable across variety of platforms => Standards • The top 1% of machines are interesting but NAG needs to focus on a broader user base. Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG’s approach to HPC Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Requirementsfrom Applications • Algorithms for variety of memory hierarchies • Implementations for a variety of platforms • Accessible from a range of languages • Conforming with different parallel paradigms • Clean application interface • Tested and reliable Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Parallel Library • Scope • Library of parallel numerical subroutines • Assortment of support routines • Target: any parallel system with MPI/PVM • shared/distributed memory computers • networks/clusters of workstations • Goals: effectiveuse of multiple processors • effective use of distributed memory Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Parallel Library - Design • Ease of use: routine interfaces • similar to sequential NAG Fortran routines • adhere to Single Program Multiple Data (SPMD) paradigm • provide distribution/in-place generation routines • Portability • Communication: BLACS + MPI/PVM • Computation: Fortran 77 + ANSI C Anne E. Trefethen Workshop on Clusters, Blackberry Farm
ScaLAPACK Structure ScaLAPACK PBLAS LAPACK BLACS BLAS PVM/MPI/... Global Local Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Parallel Library - Design • Performance • computational routines assume data is in-place • link to machine-optimized BLAS, PBLAS, etc. • relaxed error checking • Reliability • NAG or LAPACK type error checking • global argument checking & error parameter • adhere to stringent NAG quality assurance standards Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Distributed Memory Parallel Library Matrix Distribution Quadrature Eigenproblems Iterative Solvers I/O utilities Optimization Random numbers Direct Solvers (ScaLAPACK) Least-Squares (ScaLAPACK) Anne E. Trefethen Workshop on Clusters, Blackberry Farm
P I N E A P L Parallel Industrial NumErical Applications and Portable Libraries
PINEAPL Project • EU Framework IV Project in HPCN • Duration: 01/96 - 01/99 • 31.4 man-year effort • Total budget: 3.4 m ECU (2.1 m funded) • Consortium of 10 partners Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Project Objectives • Development of a General-Purpose Library of Parallel Numerical Software • Suitable for Wide Range of Computationally Intensive Industrial Applications • Portable & Efficient Across a Wide Range of Parallel Machines • Distributed Multi-processor Machines • SMPs and Clusters of SMPs • Networks of Workstations and PCs • Incorporation into the NAG Parallel Library Anne E. Trefethen Workshop on Clusters, Blackberry Farm
PINEAPL Consortium Anne E. Trefethen Workshop on Clusters, Blackberry Farm
BAe Wing design: maximum lift/minimum drag Electro-magnetics wave reflection of ducts DHI MIKE3: Estuarine and coastal hydraulics and oceanography - environmental simulation Math-Tech COSI: Oil reservoirsimulation Piaggio Engine simulation based on KIVA III: chemically reactant fluids with spray Thomson Nanometric recording devices Beam propagation in diodes pumped rod lasers End-users Applications Anne E. Trefethen Workshop on Clusters, Blackberry Farm
PINEAPL Methodology • Analyse industrial application codes • Utilise numerical expertise in participating research organisations to design and develop relevant PINEAPL Library software • Parallelize application codes using Library • Benchmark resulting parallel end-user codes Anne E. Trefethen Workshop on Clusters, Blackberry Farm
PINEAPL Library Software • Sparse linear algebra • Mesh partitioning • PDE discretization and solution • (Un)Constrained non-linear optimization • FFTs: 1-, 2- and 3-dimensional • Banded and tridiagonal solvers • Dynamic load balancing • Utility and support routines Anne E. Trefethen Workshop on Clusters, Blackberry Farm
PINEAPL Library (rel 1) • Released February ‘98 • Available free of charge for limited trial • Will be incorporated into Release 3 of NAG Parallel Library, due Q3 1998 • Available for IBM SP2, SGI Origin 2000, Fujitsu AP3000, DEC Alpha SMPs, clusters of workstations, … Anne E. Trefethen Workshop on Clusters, Blackberry Farm
For Further information: http://www.nag.co.uk/projects/PINEAPL.html To Use the Library: Available under a collaborative agreement. Contact Mishi Derakhshan mishi@nag.co.uk Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Parallel Library(rel 3) • Quantum leap in coverage! (~ 120 new) • Sparse linear algebra (~ 75 new) • Dense linear algebra • FFTs • Optimization • Graph partitioning • Tested in real-world industrial applications Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Fortran SMP Library Release 1 of the NAG Library: • Launched at HPCN ‘97 (Vienna, April 1997) • Aimed (primarily) at cache-based SMP systems • Good one processor performance • Good scalability • Includes all NAG Fortran Library Interfaces • Over 50 routines benefit Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Fortran SMP Library Parallelism on SMP systems: • Functional parallelism • Fork-Join Parallelism: Parallel Region Processes Processes Fork Join Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Fortran SMP Library • Hide details of parallelism and system dependencies • Immediate migration of code between serial & SMP systems • Compiler directives: • single source codes for serial & SMP systems • rapid migration to other SMP platforms • Levels of parallel efficiency difficult to achieve otherwise • Easy access to high-performance for non-specialist Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG Fortran SMP Library SMP Library Parallelism coded as Compiler Directives: • Coded comments ignored by Serial compiler • Different compilers have different directives grammar • Open MP: emerging standard for parallel compiler directives Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Compiler Directives A “Bestiary” or Compiler Directives: C$PAR SGI SMP systems C*KAP* Digital Alphaservers (KAP) C$PAR Sun SMP Systems *PDIR NEC SX-4 !$OMP IBM SMP systems !$OMP, C$OMP, *$OMP Open MP Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Release 1 Contents • Dense Linear Algebra • LU, QRandCholeskyfactorizations and related solvers • Symmetric eigenproblem: • reduction totridiagonal form • Compute Q • QR algorithm foreigenvalues and/or eigenvectors • FFT • Library routines interface vendor routines when these are available and perform well • New complex storage interfaces • New Nag auxiliary routines when vendors’ not available/suitable Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG SMP Library, Rel. 1 SGI SCS Library v1.0 Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG SMP Library, Rel. 1 MKL Library 2.1 Anne E. Trefethen Workshop on Clusters, Blackberry Farm
NAG SMP Library, Rel. 1 SGI SCS Library v1.0 Anne E. Trefethen Workshop on Clusters, Blackberry Farm
SMP A library of numerical software including all the functionality of the NAG Fortran library,for SMP systems. Provides a core set of high efficiency routines Completely consistent interfaces and functionality with existing NAG products NAG Parallel Libraries • Parallel • A library of numerical softwarefor distributed memory and shared memory systems • using either the PVM or MPI message-passing paradigms. • Future releases to benefit from development under PINEAPL project • Routines show good levels of performance and scalability Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Trends in HPC • Hardware • Seems to be a convergence on the clustered SMP - Hybrid machines. • Multiprocessor NT boxes also leading toward clustered SMP machine architecture. • Software • Trends harder to predict • MPI here to stay? • OpenMP • HPF possible player • C++, Java ? Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Issues for hybrid systems • Software environment… • Open MP, MPI + • Algorithmic • Deepening Memory Hierarchy Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Ongoing Investigation Consider the marriage of Parallel Library + SMP Library Networks of NT multiprocessor machines. Hybrid architectures Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Assuming an MPI + compiler directives • Questions on variety of architectures: • what can we gain over simple MPI • how portable are the algorithms across platforms Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Providing an Infrastructure • Ease of use. • Distributed pieces of application. • Visualization of application. • Interaction with application. Anne E. Trefethen Workshop on Clusters, Blackberry Farm
IRIS Explorer • Visual Programming • Drag and Drop • Modular • Extensible • Multi-platform • Heterogeneous network Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Modules Modules are the basic building blocks. Module has input and output ports for data transmission. User designed interface to module. Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Building an Application • Ports connected using mouse. • Connect to create a map - visual representation of program. • Can track execution through highlighted modules. • Parameters can be changed interactively. Anne E. Trefethen Workshop on Clusters, Blackberry Farm
The Librarian • Contains modules and maps. • Can be dragged onto map editor and ‘launched’. • Modules can be categorized in Library. • Modules on remote machines accessed by machine librarian. Anne E. Trefethen Workshop on Clusters, Blackberry Farm
The Module Builder Extend IRIS Explorer. Interface to C, C++, Fortran. Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Projects using and Expanding IRIS Explorer • Julius - solving large PDE problems. • Decision - control systems. • Stable - Statistical environment. Integration of library routines, Corba-compliance, collaborative development... Anne E. Trefethen Workshop on Clusters, Blackberry Farm
Conclusion NAG has some of the right pieces … ...figuring out how to put them together. Anne E. Trefethen Workshop on Clusters, Blackberry Farm