From: raphael couturier Date: Sun, 27 Apr 2014 10:15:47 +0000 (+0200) Subject: new abstract X-Git-Tag: hpcc2014_submission~57^2~5 X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/hpcc2014.git/commitdiff_plain/0f68e012ddd8ecc63c7f30090ff7bc057fe66d81?ds=sidebyside;hp=--cc new abstract --- 0f68e012ddd8ecc63c7f30090ff7bc057fe66d81 diff --git a/hpcc.tex b/hpcc.tex index 0dccef3..d60fd6a 100644 --- a/hpcc.tex +++ b/hpcc.tex @@ -50,9 +50,9 @@ \author{% \IEEEauthorblockN{% Charles Emile Ramamonjisoa\IEEEauthorrefmark{1}, + Lilia Ziane Khodja\IEEEauthorrefmark{2}, David Laiymani\IEEEauthorrefmark{1}, - Arnaud Giersch\IEEEauthorrefmark{1}, - Lilia Ziane Khodja\IEEEauthorrefmark{2} and + Arnaud Giersch\IEEEauthorrefmark{1} and Raphaël Couturier\IEEEauthorrefmark{1} } \IEEEauthorblockA{\IEEEauthorrefmark{1}% @@ -71,34 +71,20 @@ \maketitle -\RC{Ordre des auteurs pas définitif.} \begin{abstract} -\AG{L'abstract est AMHA incompréhensible et ne donne pas envie de lire la suite.} -In recent years, the scalability of large-scale implementation in a -distributed environment of algorithms becoming more and more complex has -always been hampered by the limits of physical computing resources -capacity. One solution is to run the program in a virtual environment -simulating a real interconnected computers architecture. The results are -convincing and useful solutions are obtained with far fewer resources -than in a real platform. However, challenges remain for the convergence -and efficiency of a class of algorithms that concern us here, namely -numerical parallel iterative algorithms executed in asynchronous mode, -especially in a large scale level. Actually, such algorithm requires a -balance and a compromise between computation and communication time -during the execution. Two important factors determine the success of the -experimentation: the convergence of the iterative algorithm on a large -scale and the execution time reduction in asynchronous mode. Once again, -from the current work, a simulated environment like SimGrid provides -accurate results which are difficult or even impossible to obtain in a -physical platform by exploiting the flexibility of the simulator on the -computing units clusters and the network structure design. Our -experimental outputs showed a saving of up to \np[\%]{40} for the algorithm -execution time in asynchronous mode compared to the synchronous one with -a residual precision up to \np{E-11}. Such successful results open -perspectives on experimentations for running the algorithm on a -simulated large scale growing environment and with larger problem size. - -\LZK{Long\ldots} + +Synchronous iterative algorithms is often less scalable than asynchronous +iterative ones. Performing large scale experiments with different kind of +networks parameters is not easy because with supercomputers such parameters are +fixed. So one solution consists in using simulations first in order to analyze +what parameters could influence or not the behaviors of an algorithm. In this +paper, we show that it is interesting to use SimGrid to simulate the behaviors +of asynchronous iterative algorithms. For that, we compare the behaviour of a +synchronous GMRES algorithm with an asynchronous multisplitting one with +simulations in which we choose some parameters. Both codes are real MPI +codes. Experiments allow us to see when the multisplitting algorithm can be more +efficience than the GMRES one to solve a 3D Poisson problem. + % no keywords for IEEE conferences % Keywords: Algorithm distributed iterative asynchronous simulation SimGrid