Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands Component Approach to Distributed Multiscale Simulations Katarzyna Rycerz(1,2), Marian Bubak(1,3) (1) AGH University of Technology, Institute of Computer Science AGH, Mickiewicza 30, 30-059 Kraków, Poland (2) ACC Cyfronet AGH, ul. Nawojki 11, 30-950 Kraków, Poland (3)University of Amsterdam, Institute for Informatics, Amsterdam, The Netherlands
21
Embed
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands Component Approach to Distributed Multiscale Simulations Katarzyna Rycerz(1,2), Marian.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands
Component Approach to Distributed Multiscale Simulations
Katarzyna Rycerz(1,2), Marian Bubak(1,3)
(1) AGH University of Technology, Institute of Computer Science AGH, Mickiewicza 30, 30-059 Kraków, Poland
(2) ACC Cyfronet AGH, ul. Nawojki 11, 30-950 Kraków, Poland
(3)University of Amsterdam, Institute for Informatics, Amsterdam, The Netherlands
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands
Outline
• Requirements of multiscale simulations• Motivation for a component model for such
challenges and solutions• Experiment with Multiscale Multiphysics
Scientific Environment (MUSE)• Execution in GridSpace VL (demo)• Summary
Multiscale SimulationsConsists of modules of
different scale
Examples:virtual physiological
human initiative
reacting gas flows
capillary growth
colloidal dynamics
stellar systems
and many more ...
virtual physiological humanvirtual physiological human fusionfusion hydrologyhydrology
nano material sciencenano material science computational biologycomputational biology
the reoccurrence of stenosis, a
narrowing of a blood vessel, leading to
restricted blood flow
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands
Multiscale Simulations - Requirements• Actual connection of two or more models together
• obeying laws of physics (e.g. conservation law) • advanced time management: ability to connect modules
with different time scales and internal time management
• support for connecting models of different space scale• Composability and reusability of existing models of
different scale• finding existing models needed and connecting them
either together or to new models• ease of plugging in and unplugging of models from a
running system• standarized models’ connections + many users sharing
their models = more chances for general solutions
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands
Motivation• To wrap simulations into recombinant components that can be
selected and assembled in various combinations to satisfy requirements of multiscale simulations • machanisms specyfic for distributed multiscale simulation
• adaptation of one of the existing solutions for distributed simulations – our choice – High Level Architecture (HLA)
• support for long running simulations - setup and steering of components should be possible also during runtime
• possibility to wrap legacy simulation kernels into components
• Need for an infrastructure that facilitates cross-domain exchange of components among scientists• need for support for the component model • using Grid solutions (e-infrastructures) for crossing
administrative domains
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands
Related Work• Model Coupling Toolkit
• message passing (MPI) style of communication between simulation models.
• domain data decomposition of the simulated problem
• support for advanced data transformations between different models
• J. Larson, R. Jacob, E. Ong ”The Model Coupling Toolkit: A New Fortran90 Toolkit for Building Multiphysics Parallel Coupled Models.” 2005: Int. J. High Perf. Comp. App.,19(3), 277-292.
• Multiscale Multiphysics Scientific Environment (MUSE), now AMUSE
• The Astrophysical Multi-Scale Environment
• scripting approach (Python) is used to couple models together.
• models include: stellar evolution, hydrodynamics, stellar dynamics and radiative transfer
• S. Portegies Zwart, S. McMillan, at al. A Multiphysics and Multiscale Software Environment for Modeling Astrophysical Systems, New Astronomy, volume 14, issue 4, year 2009, pp. 369 - 378
• The Multiscale Coupling Library and Environment (MUSCLE)
• a software framework to build simulations according to the complex automata theory
• concept of kernels that communicate by unidirectional pipelines dedicated to pass a specific kind of data from/to a kernel (asynchronous communication)
• J. Hegewald, M. Krafczyk, at al.. An agent-based coupling platform for complex automata. ICCS, volume 5102 of Lecture Notes in Computer Science, pages 227-233. Springer, 2008.
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands
Why High Level Architecture (HLA) ?• Introduces the concept of simulation systems (federations)
built from distributed elements (federates)
• Supports joining models of different time scale - ability to connect simulations with different internal time management in one system
• Supports data management (publish/subscribe mechanism)
• Separates actual simulation from communication between fedarates
• Partial support for interoperability and reusability (Simulation Object Model (SOM), Federation Object Model (FOM), Base Object Model (BOM))
• mass of changed stars are sent from evolution (macro scale) to dynamics (meso scale)
• no data is needed from dynamics to evolution
• data flow affects whole dynamics simulation
• Dynamics takes more steps than evolution to reach the same point of simulation time
• Time management - regulating federate (evolution) regulate the progress in time of constrained federate (dynamics)
• The maximal point in time which the constrained federate can reach (LBTS) at certain moment is calculated dynamically according to the position of regulating federate on the time axis
LBTS - Other federates will not send messages before this time.
Federate may only advance time within this interval
Federate’s current logical time.
Federate’s
effective logical time.
Federate may not publish messages within this interval
Federate’s current logical time.
t=0
Lookahead
Constrained federate(dynamics)
Regulating federate (evolution)
Simultech 2011, 29-31 July, 2011, Noordwijkerhout, The Netherlands