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- Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU
- Path: sparky!uunet!paladin.american.edu!auvm!LIBRARY.TMC.EDU!SANJAY_CHADHA
- Message-ID: <9212221709.AA07208@tmcpcnet.tmc.edu>
- Newsgroups: bit.listserv.medlib-l
- Date: Tue, 22 Dec 1992 11:17:00 CST
- Sender: Medical Libraries Discussion List <MEDLIB-L@UBVM.BITNET>
- From: Sanjay_Chadha@LIBRARY.TMC.EDU
- Subject: RE:Dos in Unix Networks
- Lines: 43
-
- Alan Pridemore has asked:
-
- >So, can we say that the fileserver can be running operating
- >system "A" while workstations are running operating systems
- >"B", "C", and "D" and the protocol is the common language by
- >which the three workstations' operating systems communicate
- >(i.e. make "read" and "write" requests) with the fileserver?
-
- That is correct. That is also what you do when you FTP a file for
- example. When both machines are using TCP/IP, one in DOS, other VMS,
- either machine may read or write a file, provided, user signed on is
- permitted. This is not limited to TCP/IP and is true of all protocols.
- The OS or the NOS (Network Operating System) may enforce what you may do
- though.
-
- >And here, instead of the fileserver "downloading" a file
- >(application) to the workstation's memory, the application is
- >run on the fileserver. Do you know if ONE copy on the fileserver
- >is to accomodate MANY workstations running that application
- >simultaneously? Lately I've been hearing "network version of an
- >application". Is this the version of an application that will
- >"handle" many users simultaneously, and reside on the fileserver?
- >The added traffic along network lines is mind-boggleing!
-
- In most cases, it will be one copy with multiple licenses (true for
- network versions of softwares). Essentially, it depends upon how the
- software was written, eg. some of the older softwares can be run on
- networks with MULTIPLE users using them without any networking control,
- the newer versions control how many people are using it. Now, in an
- application server, while ONLY when copy may reside, it will be loaded
- in MANY sessions, one for each user, at least for existing software.
- Some server level software will simply assign a thread to each new user
- eg. Sybase SQL server will NOT load a second copy of itself when a
- second user tries to access it, but under the current APP Server
- technology, a second "instance" of Wordperfect WILL be loaded on the the
- App Server. Contrary to what you may beleive, this CUTS down on the
- network traffic significantly, as only the I/O parts have to be ported
- to and from the workstation, versus the actual program.
-
-
- Sanjay R. Chadha
- sanjayc@library.tmc.edu
- HAm-TMC Library, HOUSTON
-