Distributed Computing Environment: Difference between revisions

Revision as of 08:41, 19 August 2006

Revision as of 10:48, 20 September 2006

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DCE came about to a large degree as part of the [[Unix wars]] of the 1980s. After [[Sun Microsystems]] and [[AT&T]] worked together to produce [[UNIX System V|UNIX System V Release 4]] (SVR4), many of the other Unix vendors felt their own market opportunities were unduly disadvantaged. They quickly formed the [[Open Software Foundation]] (OSF) to compete with a [[BSD]]-based Unix that more closely matched their own offerings. OSF ended up introducing [[OSF/1]], which was based on the [[Mach kernel]] and had relatively poor performance compared to SVR4, and was little used except by Digital.

As part of the formation of OSF, the various members contributed many of their ongoing research projects. At the time, network computing was "all the rage", and many of the companies involved were working on similar RPC-based systems. By re-building these various utilities on a single "official" RPC mechanism, OSF could offer a major advantage over SVR4, allowing any DCE-supporting system (namely OSF/1) to interoperate in a larger network.

The DCE system was, to a large degree, based on independent developments made by each of the partners. DCE/RPC was derived from the [[''Network Computing System]]'' (NCS) created at Apollo Computer. The naming service was derived from work done at Digital. DCE/DFS was based on the [[Andrew file system]] (AFS) originally developed at [[Carnegie Mellon University]]. The authentication system was based on [[Kerberos]], and the authorization system based on [[Access Control List]]s (ACLs). By combining these features, DCE offers a fairly complete [[C programming language|C]]-based system for network computing. Any machine on the network can authenticate its users, gain access to resources, and then call them remotely using a single integrated [[Application Programming Interface|API]].

Distributed computing never really caught on as much as had been hoped for in the late 1980s and early 1990s. The rise of the [[Internet]], [[Java programming language|Java]] and [[web services]] stole much of its [[mindshare]] through the mid-to-late 1990s, and competing systems such as [[CORBA]] muddied the waters as well. Perhaps ironically, one of the major uses of DCE/RPC today isare [[Microsoft]]'s [[Distributed_component_object_model|DCOM]] and [[ODBC]] systems, which use DCE/RPC (in [[MSRPC]]) as their network transport layer.

OSF and its projects eventually became part of [[The Open Group]], which released DCE 1.2.2 under a [[free software license]] (the [[GNU Lesser General Public License|LGPL]]) on [[12 January]] [[2005]]. DCE 1.1 was available much earlier under the OSF BSD license, and resulted in FreeDCE[http://freedce.sf.net|FreeDCE] being available since [[2000]]. FreeDCE contains an implementation of DCOM.

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