\section{Other strategies}
\label{Other}
-\FIXME{Réécrire en angliche.}
+\FIXME{Réécrire en anglais.}
% \FIXME{faut-il décrire les stratégies makhoul et simple ?}
number of computing iterations (2000 in our case).
Note that this convergence detection was implemented in a centralized manner.
-This is easy to do within the simulator, but it's obviously not realistic. In
-a real application we would have chosen a decentralized convergence detection algorithm, like the one described in \cite{10.1109/TPDS.2005.2}.
+This is easy to do within the simulator, but it's obviously not realistic. In a
+real application we would have chosen a decentralized convergence detection
+algorithm, like the one described in \cite{10.1109/TPDS.2005.2}.
\paragraph{Platforms}
sorts of platforms differ by their underlaid network topology. On the one hand,
we have homogeneous platforms, modeled as a cluster. On the other hand, we have
heterogeneous platforms, modeled as the interconnection of a number of clusters.
+
+The clusters were modeled by a fixed number of computing nodes interconnected
+through a backbone link. Each computing node has a computing power of
+1~GFlop/s, and is connected to the backbone by a network link whose bandwidth is
+of 125~MB/s, with a latency of 50~$\mu$s. The backbone has a network bandwidth
+of 2.25~GB/s, with a latency of 500~$\mu$s.
+
The heterogeneous platform descriptions were created by taking a subset of the
Grid'5000 infrastructure\footnote{Grid'5000 is a French large scale experimental
Grid (see \url{https://www.grid5000.fr/}).}, as described in the platform file
\texttt{g5k.xml} distributed with SimGrid. Note that the heterogeneity of the
-platform only comes from the network topology. The processor speeds, and
-network bandwidths were normalized since our algorithms currently are not aware
-of such heterogeneity. We arbitrarily chose to fix the processor speed to
-1~GFlop/s, and the network bandwidth to 125~MB/s, with a latency of 50~$\mu$s,
-except for the links between geographically distant sites, where the network
-bandwidth was fixed to 2.25~GB/s, with a latency of 500~$\mu$s.
+platform here only comes from the network topology. Indeed, since our
+algorithms currently do not handle heterogeneous computing resources, the
+processor speeds were normalized, and we arbitrarily chose to fix them to
+1~GFlop/s.
Then we derived each sort of platform with four different number of computing
nodes: 16, 64, 256, and 1024 nodes.
that can be compared between simulations of different sizes.
This metric is expected to give an idea of the ability of the strategy to
- diffuse the load quickly, lesser is better.
+ diffuse the load quickly. A smaller value is better.
\item[\textbf{average convergence date:}] that's the average of the dates when
all nodes reached the convergence state. The dates are measured as a number
reached the convergence state.
These two dates give an idea of the time needed by the strategy to reach the
- equilibrium state, lesser is doubtlessly better.
+ equilibrium state. A smaller value is better.
-\item[\textbf{data transfer amount:}] that's the sum of the amount of data of
- all transfers during the simulation. This sum is then normalized by dividing
- it by the total amount of data present in the system.
+\item[\textbf{data transfer amount:}] that's the sum of the amount of all data
+ transfers during the simulation. This sum is then normalized by dividing it
+ by the total amount of data present in the system.
This metric is expected to give an idea of the efficiency of the strategy in
terms of data movements, i.e. its ability to reach the equilibrium with fewer
- transfers.
+ transfers. Again, a smaller value is better.
\end{description}
% LocalWords: Raphaël Couturier Arnaud Giersch Abderrahmane Sider Franche ij
% LocalWords: Bertsekas Tsitsiklis SimGrid DASUD Comté Béjaïa asynchronism ji
-% LocalWords: ik isend irecv Cortés et al chan ctrl fifo Makhoul
+% LocalWords: ik isend irecv Cortés et al chan ctrl fifo Makhoul GFlop xml
