X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/loba-papers.git/blobdiff_plain/d883af6fcab703af629fd6ca368b7076b5b3384a..2216578e9740572a34f3064af72777d9fc281fe2:/supercomp11/supercomp11.tex?ds=inline diff --git a/supercomp11/supercomp11.tex b/supercomp11/supercomp11.tex index d1ff213..6a48cd3 100644 --- a/supercomp11/supercomp11.tex +++ b/supercomp11/supercomp11.tex @@ -122,7 +122,29 @@ conclusion and some perspectives to this work. \section{Bertsekas and Tsitsiklis' asynchronous load balancing algorithm} \label{BT algo} -Comment on the problem in the convergence condition. +In order prove the convergence of asynchronous iterative load balancing +Bertesekas and Tsitsiklis proposed a model +in~\cite{bertsekas+tsitsiklis.1997.parallel}. Here we recall some notations. +Consider that $N={1,...,n}$ processors are connected through a network. +Communication links are represented by a connected undirected graph $G=(N,V)$ +where $V$ is the set of links connecting differents processors. In this work, we +consider that processors are homogeneous for sake of simplicity. It is quite +easy to tackle the heterogeneous case~\cite{ElsMonPre02}. Load of processor $i$ +at time $t$ is represented by $x_i(t)\geq 0$. Let $V(i)$ be the set of +neighbors of processor $i$. Each processor $i$ has an estimate of the load of +each of its neighbors $j \in V(i)$ represented by $x_j^i(t)$. According to +asynchronism and communication delays, this estimate may be outdated. We also +consider that the load is described by a continuous variable. + +When a processor send a part of its load to one or some of its neighbors, the +transfer takes time to be completed. Let $s_{ij}(t)$ be the amount of load that +processor $i$ has transfered to processor $j$ at time $t$ and let $r_{ij}(t)$ be the +amount of load received by processor $j$ from processor $i$ at time $t$. Then +the amount of load of processor $i$ at time $t+1$ is given by: +\begin{equation} +x_i(t+1)=x_i(t)-\sum_{j\in V(i)} s_{ij}(t) + \sum_{j\in V(i)} r_{ji}(t) +\end{equation} + \section{Best effort strategy} \label{Best-effort} @@ -135,9 +157,17 @@ Comment on the problem in the convergence condition. \section{Simulations} \label{Simulations} +In order to test and validate our approaches, we wrote a simulator +using the SimGrid +framework~\cite{casanova+legrand+quinson.2008.simgrid}. The process +model is detailed in the next section (\ref{Sim model}), then the +results of the simulations are presented in section~\ref{Results}. + \subsection{Simulation model} +\label{Sim model} \subsection{Validation of our approaches} +\label{Results} On veut montrer quoi ? :