version 1.3, 2001/06/20 02:39:25 |
version 1.6, 2001/06/20 03:18:21 |
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% $OpenXM: OpenXM/doc/ascm2001p/homogeneous-network.tex,v 1.2 2001/06/20 01:43:12 noro Exp $ |
% $OpenXM: OpenXM/doc/ascm2001p/homogeneous-network.tex,v 1.5 2001/06/20 03:08:05 takayama Exp $ |
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\subsection{Distributed computation with homogeneous servers} |
\subsection{Distributed computation with homogeneous servers} |
\label{section:homog} |
\label{section:homog} |
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One of the aims of OpenXM is a parallel speedup by a distributed computation |
One of the aims of OpenXM is a parallel speedup by a distributed computation |
with homogeneous servers. As the current specification of OpenXM does |
with homogeneous servers. |
not include communication between servers, one cannot expect |
%As the current specification of OpenXM does |
the maximal parallel speedup. However it is possible to execute |
%not include communication between servers, one cannot expect |
several types of distributed computation as follows. |
%the maximal parallel speedup. However it is possible to execute |
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%several types of distributed computation as follows. |
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\subsubsection{Competitive distributed computation by various strategies} |
\subsubsection{Competitive distributed computation by various strategies} |
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SINGULAR \cite{Singular} implements {\it MP} interface for distributed |
SINGULAR \cite{Singular} implements {\it MP} interface for distributed |
computation and a competitive Gr\"obner basis computation is |
computation and a competitive Gr\"obner basis computation is |
illustrated as an example of distributed computation. |
illustrated as an example of distributed computation. |
Such a distributed computation is also possible on OpenXM as follows: |
Such a distributed computation is also possible on OpenXM. |
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The client creates two servers and it requests |
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Gr\"obner basis comutations by the Buchberger algorithm the $F_4$ algorithm |
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to the servers for the same input. |
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The client watches the streams by {\tt ox\_select()} |
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and the result which is returned first is taken. Then the remaining |
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server is reset. |
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\begin{verbatim} |
\begin{verbatim} |
extern Proc1,Proc2$ |
extern Proc1,Proc2$ Proc1 = -1$ Proc2 = -1$ |
Proc1 = -1$ Proc2 = -1$ |
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/* G:set of polys; V:list of variables */ |
/* G:set of polys; V:list of variables */ |
/* Mod: the Ground field GF(Mod); O:type of order */ |
/* Mod: the Ground field GF(Mod); O:type of order */ |
def dgr(G,V,Mod,O) |
def dgr(G,V,Mod,O) |
Line 49 def dgr(G,V,Mod,O) |
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Line 42 def dgr(G,V,Mod,O) |
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return [Win,R]; |
return [Win,R]; |
} |
} |
\end{verbatim} |
\end{verbatim} |
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In the above Asir program, the client creates two servers and it requests |
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Gr\"obner basis comutations by the Buchberger algorithm the $F_4$ algorithm |
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to the servers for the same input. |
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The client watches the streams by {\tt ox\_select()} |
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and the result which is returned first is taken. Then the remaining |
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server is reset. |
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%\subsubsection{Nesting of client-server communication} |
\subsubsection{Nesting of client-server communication} |
% |
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%Under OpenXM-RFC 100 an OpenXM server can be a client of other servers. |
Under OpenXM-RFC 100 an OpenXM server can be a client of other servers. |
%Figure \ref{tree} illustrates a tree-like structure of an OpenXM |
Figure \ref{tree} illustrates a tree-like structure of an OpenXM |
%client-server communication. |
client-server communication. |
%\begin{figure} |
\begin{figure} |
%\label{tree} |
\label{tree} |
%\begin{center} |
\begin{center} |
%\begin{picture}(200,70)(0,0) |
\begin{picture}(200,70)(0,0) |
%\put(70,70){\framebox(40,15){client}} |
\put(70,70){\framebox(40,15){client}} |
%\put(20,30){\framebox(40,15){server}} |
\put(20,30){\framebox(40,15){server}} |
%\put(70,30){\framebox(40,15){server}} |
\put(70,30){\framebox(40,15){server}} |
%\put(120,30){\framebox(40,15){server}} |
\put(120,30){\framebox(40,15){server}} |
%\put(0,0){\framebox(40,15){server}} |
\put(0,0){\framebox(40,15){server}} |
%\put(50,0){\framebox(40,15){server}} |
\put(50,0){\framebox(40,15){server}} |
%\put(150,0){\framebox(40,15){server}} |
\put(150,0){\framebox(40,15){server}} |
% |
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%\put(90,70){\vector(-2,-1){43}} |
\put(90,70){\vector(-2,-1){43}} |
%\put(90,70){\vector(0,-1){21}} |
\put(90,70){\vector(0,-1){21}} |
%\put(90,70){\vector(2,-1){43}} |
\put(90,70){\vector(2,-1){43}} |
%\put(40,30){\vector(-2,-1){22}} |
\put(40,30){\vector(-2,-1){22}} |
%\put(40,30){\vector(2,-1){22}} |
\put(40,30){\vector(2,-1){22}} |
%\put(140,30){\vector(2,-1){22}} |
\put(140,30){\vector(2,-1){22}} |
%\end{picture} |
\end{picture} |
%\caption{Tree-like structure of client-server communication} |
\caption{Tree-like structure of client-server communication} |
%\end{center} |
\end{center} |
%\end{figure} |
\end{figure} |
%Such a computational model is useful for parallel implementation of |
Such a computational model is useful for parallel implementation of |
%algorithms whose task can be divided into subtasks recursively. |
algorithms whose task can be divided into subtasks recursively. |
% |
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%A typical example is {\it quicksort}, where an array to be sorted is |
%A typical example is {\it quicksort}, where an array to be sorted is |
%partitioned into two sub-arrays and the algorithm is applied to each |
%partitioned into two sub-arrays and the algorithm is applied to each |
%sub-array. In each level of recursion, two subtasks are generated |
%sub-array. In each level of recursion, two subtasks are generated |
Line 132 def dgr(G,V,Mod,O) |
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Line 131 def dgr(G,V,Mod,O) |
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%} |
%} |
%\end{verbatim} |
%\end{verbatim} |
% |
% |
%A typical example is a parallelization of the Cantor-Zassenhaus |
A typical example is a parallelization of the Cantor-Zassenhaus |
%algorithm for polynomial factorization over finite fields. |
algorithm for polynomial factorization over finite fields. |
%which is a recursive algorithm. |
which is a recursive algorithm. |
%At each level of the recursion, a given polynomial can be |
At each level of the recursion, a given polynomial can be |
%divided into two non-trivial factors with some probability by using |
divided into two non-trivial factors with some probability by using |
%a randomly generated polynomial as a {\it separator}. |
a randomly generated polynomial as a {\it separator}. |
%We can apply the following simple parallelization: |
We can apply the following simple parallelization: |
%When two non-trivial factors are generated on a server, |
When two non-trivial factors are generated on a server, |
%one is sent to another server and the other factor is factorized on the server |
one is sent to another server and the other factor is factorized on the server |
%itself. |
itself. |
%\begin{verbatim} |
%\begin{verbatim} |
%/* factorization of F */ |
%/* factorization of F */ |
%/* E = degree of irreducible factors in F */ |
%/* E = degree of irreducible factors in F */ |