Distributed Operating System,Network OS and Middle-ware.??
Assignment Distributed Computing Submitted To Ms.Rabia Latif Submitted By Abdul-rehman Aslam Class BSSE 7Th Roll No 9998NATIONAL UNIVERSITY OF MODERN LANGUAGES ISLAMABAD 13, December 2012 3|Page
Question:-Define Distributed Operating System, Network OperatingSystem and Middle-ware? Differentiate between DOS,NOS and Middle-ware? Define the goals of each?Distributed Operating System:Distributed Means Data is Stored and Processed on Multiple Locations.OrAn operating system which manages a collection of independent computers andmakes them appear to the users of the system as a single computer.Network Operating System:Network operating system is also referred to as the Dialoguer. It is the softwarethat runs on a server and enables the server to manage data, users, groups,security, applications, and other networking functions. The most popular networkoperating systems are Microsoft Windows Server 2003 Microsoft Windows Server 2008 Unix Linux Mac OS X Novell NetWare BSD 4
Middle-ware:Middleware is computer software that provides services to software applicationsbeyond those available from the operating system. It can be described as"software glue".OrThe glue which connects objects which are distributed across multipleheterogeneous computer systems. 5
Difference between DOS, NOS and Middleware: DOS NOS Middleware Tightly-coupled operating Loosely-coupled Additional layer atop of system for multi- operating system for NOS implementing processors and heterogeneous multi- general-purpose services homogeneous computers (LAN and multi-computers. WAN) Follow n tier Client server Follow 2 tier Client server architecture architecture Distributed OS Item Network Middleware- Multiproc. Multicomp. OS based OSDegree of transparency Very High High Low HighSame OS on all nodes Yes Yes No NoNumber of copies of OS 1 N N NBasis for communication Shared Messages Files Model specific memoryResource management Global, Global, Per node Per node central distributed 6
Scalability No Moderately Yes VariesOpenness Closed Closed Open Open Goals of Distributed Operating System: The main goal of distributed operating systems is the following. Hide and manage hardware resources. Transparent performance Scalability Fault tolerance Consistency Goals of Network Operating System: The main goals of network operating systems are the following. Offer local services to remote clients Goals of Middleware: The goals of middleware are Provide distribution transparency Integrate existing component into a distributed system Resolve heterogeneity 7