\ead{arnaud.giersch@femto-st.fr}
\address{FEMTO-ST, University of Franche-Comté\\
- 19 avenue de Maréchal Juin, BP 527, 90016 Belfort cedex , France\\
- % Tel.: +123-45-678910\\
- % Fax: +123-45-678910\\
-}
+ 19 avenue du Maréchal Juin, BP 527, 90016 Belfort cedex, France}
\cortext[cor]{Corresponding author.}
time.
\subsubsection{Metrics}
+\label{sec.metrics}
In order to evaluate and compare the different load balancing strategies we had
to define several metrics. Our goal, when choosing these metrics, was to have
This suggests that the relative performances of the different strategies are not
influenced by the characteristics of the physical platform. The differences in
the convergence times can be explained by the fact that on the grid platforms,
-distant sites are interconnected by links of smaller bandwith.
+distant sites are interconnected by links of smaller bandwidth.
Therefore, in the following, we'll only discuss the results for the grid
platforms.
when the load to balance is initially randomly distributed over all nodes.
On both figures, the computation/communication cost ratio is $10/1$ on the left
-column, and $1/10$ on the right column. With a computatio/communication cost
+column, and $1/10$ on the right column. With a computation/communication cost
ratio of $1/1$ the results are just between these two extrema, and definitely
don't give additional information, so we chose not to show them here.
are given for the process topology being, from top to bottom, a line, a torus or
an hypercube.
-\FIXME{explain how to read the graphs}
+Finally, on the graphs, the vertical bars show the measured times for each of
+the algorithms. These measured times are, from bottom to top, the average idle
+time, the average convergence date, and the maximum convergence date (see
+Section~\ref{sec.metrics}). The measurements are repeated for the different
+platform sizes. Some bars are missing, specially for large platforms. This is
+either because the algorithm did not reach the convergence state in the
+allocated time, or because we simply decided not to run it.
-each bar -> times for an algorithm
-recall the different times
-no bar -> not run or did not converge in allocated time
+\FIXME{annoncer le plan de la suite}
-repeated for the different platform sizes.
+\subsubsection{The \emph{best effort} strategy}
-\FIXME{donner les premières conclusions, annoncer le plan de la suite}
+Looking at the graph on figure~\ref{fig.results1}, we can see that the
+\emph{best effort} strategy is not too bad.
+
+\FIXME{donner les premières conclusions}
+\FIXME{comparer be/makhoul -> be tient la route (parler du cas réel uniquement)}
\subsubsection{With the virtual load extension}
+\FIXME{valider l'extension virtual load -> c'est 'achement bien}
+
\subsubsection{The $k$ parameter}
-\subsubsection{With an initial random repartition, and larger platforms}
+\FIXME{proposer le -k -> ça peut aider dans certains cas}
+
+\subsubsection{With an initial random distribution, and larger platforms}
+
+\FIXME{dire quoi ici ?}
\subsubsection{With integer load}
+\FIXME{conclure avec la version entière -> on n'a pas l'effet d'escalier !}
+
\FIXME{what about the amount of data?}
-\begin{itshape}
-\FIXME{remove that part}
-Dans cet ordre:
-...
-- comparer be/makhoul -> be tient la route
- -> en réel uniquement
-- valider l'extension virtual load -> c'est 'achement bien
-- proposer le -k -> ça peut aider dans certains cas
-- conclure avec la version entière -> on n'a pas l'effet d'escalier !
-Q: comment inclure les types/tailles de platesformes ?
-Q: comment faire des moyennes ?
-Q: comment introduire les distrib 1/N ?
-...
-
-On constate quoi (vérifier avec les chiffres)?
+\FIXME{On constate quoi (vérifier avec les chiffres)?
\begin{itemize}
\item cluster ou grid, entier ou réel, ne font pas de grosses différences
-
\item bookkeeping? améliore souvent les choses, parfois au prix d'un retard au démarrage
-
\item makhoul? se fait battre sur les grosses plateformes
-
\item taille de plateforme?
-
\item ratio comp/comm?
-
\item option $k$? peut-être intéressant sur des plateformes fortement interconnectées (hypercube)
-
\item volume de comm? souvent, besteffort/plain en fait plus. pourquoi?
-
\item répartition initiale de la charge ?
-
\item integer mode sur topo. line n'a jamais fini en plain? vérifier si ce n'est
pas à cause de l'effet d'escalier que bk est capable de gommer.
-
-\end{itemize}
+\end{itemize}}
% On veut montrer quoi ? :
% Prendre un réseau hétérogène et rendre processeur homogène
% Taille : 10 100 très gros
-\end{itshape}
\section{Conclusion and perspectives}
\FIXME{conclude!}
-\section*{Acknowledgements}
+\section*{Acknowledgments}
Computations have been performed on the supercomputer facilities of the
Mésocentre de calcul de Franche-Comté.
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+% LocalWords: Raphaël Couturier Arnaud Giersch Franche ij Bertsekas Tsitsiklis
+% LocalWords: SimGrid DASUD Comté asynchronism ji ik isend irecv Cortés et al
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+% LocalWords: cdde Contassot Vivier underlaid du de Maréchal Juin cedex calcul
+% LocalWords: biblio
