[comp.os.research] STRUCTURING DISTRIBUTED APPLICATIONS AS FRAGMENTED OBJECTS

shapiro@xombul.inria.fr (Marc Shapiro) (03/21/91)

The following Technical Report is available:

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      STRUCTURING DISTRIBUTED APPLICATIONS AS FRAGMENTED OBJECTS
 Mesaac Makpangou, Yvon Gourhant, Jean-Pierre Le Narzul, Marc Shapiro
				   
		   Rapport de Recherche INRIA 1404
			    February 1991

			       Abstract

Most distributed systems offer only primitive communication objects
(e.g. channels). Their undisciplined use obscures, and exposes the
implementation of, higher-level concepts.

We propose instead a high-level, structured approach, called
Fragmented Objects.  A Fragmented Object is a distributed shared
object.  Clients see a fragmented object as an ordinary object.  The
implementor of a fragmented object decides of its interface and
representation, including (if necessary) aspects such as placement of
data items, communication between fragments, protocol layering, and
binding.  The fragmented object model provides a common framework for
different distribution mechanisms, such as client/server stubs,
replication, cacheing, and data partitioning.

We present the basic fragmented object concepts and a full example,
the SOS Naming Service, layered into Name Space and Naming View
objects.  Each of these layers is implemented as fragmented objects;
we point out specific benefits of the fragmented object approach.

We have defined a fragmented-object language called FOG, a compiler,
and a toolkit of primitive fragmented objects. The compiler enforces
encapsulation, checks interface consistency, and generates hooks to
the toolkit. The compiler and the toolkit facilitate the most common
distribution policies.

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    -r--r--r--  1 shapiro     62541 Mar 19 11:31 RR-1404-dvips.tar.Z
    -r--r--r--  1 shapiro    121027 Mar 19 11:31 RR-1404.ps.Z

-- 
						Marc Shapiro

INRIA, B.P. 105, 78153 Rocquencourt Cedex, France.  Tel.: +33 (1) 39-63-53-25;
fax: +33 (1) 39-63-53-30; e-mail: shapiro@sor.inria.fr