CompFrame 2003 Workshop

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CompFrame 2003 Workshop

• A development platform for parallel applications
• E-Mail
• palm_at_cerfacs.fr

2
Plan

• Origin and concepts
• Building a PALM application
• Supervision tools
• Some applications using PALM

3
Plan

• Origin and concepts
• Building a PALM application
• Supervision tools
• Some applications using PALM

4
Origin
buis projet créé dans le milieu des annees 90 à
partir dun constat ou pour répondre a un
problème précis -gt exemple en NWP modele de
plus en plus complexe prenant en compte de plus
en plus de composants physique mais aussi des
composants mathematique assimilation de
donnees, desfois aussi avec des resolution ou des
dommaines differents, le tout gere avec cle CPP,

Scientific computing applications
Scientific computing applications
Scientific computing applications
Scientific computing applications
Scientific computing applications
buis -gt Cest le but de palm
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Origin
buis projet créé dans le milieu des annees 90 à
partir dun constat ou pour répondre a un
problème précis -gt exemple en NWP modele de
plus en plus complexe prenant en compte de plus
en plus de composants physique mais aussi des
composants mathematique assimilation de
donnees, desfois aussi avec des resolution ou des
dommaines differents, le tout gere avec cle CPP,

buis -gt Cest le but de palm
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Concepts
buis -gt lidée de PALM cest de pouvoir
construire des applications a partir de briques
de bases indépendante entre elles (code source
avec donnees quelles consomme et produise) et
indépendante de lapplication. Subroutine fortran
pour 1ere version PALM, exe C, fort C pour
MP -gt a partir dun jeu dunites, les assembler
en sequences pour créer des appli modulaire et
facilement evolutive (integration de nouveaux
composants, ) sans changer le code source.

• buis
• Unites indep
• Integration de lappli -gt facilement modifiable,
  extensible,
• Voc PALM

Source code library
Applications
I N T E G R A T I O N
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How PALM ensures the independency between the
units ?
buis Faire animation remapping

• end-point communication scheme
• automatic remapping during the communications
• no reference to the application algorithm in the
  units the description of the application
  algorithm is made in the GUI, during the
  integration phase

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How PALM ensures the performance of the
applications

• 2 levels of parallelism

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How PALM ensures the performance of the
application

• High performance communication mechanism

memory copies
MPI messages
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Plan

• Origin and concepts
• Building a PALM application
• Supervision tools
• Some applications using PALM

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On units side

• Units instrumentation
• Source end-point
• CALL PALM_Put (space1, obj1, time, tag ,
  array, error)
• Target end-point
• CALL PALM_Get (space2, obj2, time, tag ,
  array, error)

• Units IDCARD

!PALM_UNIT -sub create\ ! !PALM_SPACE name
space1\ ! -shape (10,10)\ !
-element_size PL_DOUBLE_PRECISION\ ! !PALM_OBJEC
T -name obj1\ ! -space space1\ !
-intent OUT\
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Definition of the algorithm in PrePALM

• Launch units
• Conditional execution
• DO, While loops
• Communications

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Definition of the communication scheme
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buis General overview of the application Algorith
m components decomposition, control
structure, Data flux Parallelism branches,
units Physics, algebra Mettre des fleches ???
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Plan

• Origin and concepts
• Building a PALM application
• Supervision tools
• Some applications using PALM

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Supervision tools
buis Faire une animation pour passer de
graphical stat a limage,

• debug functions can be called during PALM_PUT and
  PALM_GET to verify the objects values

• an output file per processes of the application
  containing information about the run with several
  levels of verbosity per message category

• performance analyser with graphical statistic
  summaries

• graphical animation

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Performance analyser
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Graphical animation
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Plan

• Origin and concepts
• Building a PALM application
• Supervision tools
• Some applications using PALM

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• French contribution to the international
  experiment GODAE (Global Ocean Data Assimilation
  Experiment).
• Partners
• Aim implement an operational oceanic forecast
  system able to simulate the global ocean with a
  high resolution model by assimilating in-situ and
  satellite data
• Strategy from regional to global model
• from simple (OI) to complex (SEEK, 4DVAR)
  assimilation method

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The operational system
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The MERCATOR bulletin
HIGH RESOLUTION REGIONAL PROTOTYPE 1/15
Mediterranean-North-Atlantic model assimilating
altimeter data

• 4D description of the ocean Temperature,
  Salinity, Currents, SSH, movements of water
  masses
• Each Wednesday (analyses and 7 days and 14 days
  forecast).

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The MERCATOR website
http//www.mercator.com.fr
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ASSET Assimilation of Envisat Data

• a European project to exploit and develop earth
  observation data from Envisat satellite using
  data assimilation
• (January 2003 ? December 2005)
• aims
• develop a European capability for chemical and UV
  forecasting
• provide analyses for coupled climate / chemistry
  studies
• partners , .

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ASSET Assimilation of Envisat Data
buis Rajouter PALM dans le schema
Data
Model
Data Assimilation Methods
assimilation of retrieved Envisat data into a
coupled NWP/chemistry system
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A Fluid structure coupling application
elsA an ONERA AIRBUS CERFACS oriented object
compressible flows simulation software
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Information and Documentations
A website http//www.cerfacs.fr/palm A
software PALM_Research already available and
free PALM_MP beta version in April A course A
3 days free course is regularly organised An
email palm_at_cerfacs.fr

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Difference between SPMD and MPMD
Program model end
Program assim end