• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

What do we mean by distributed systems?

Extracts from this document...

Introduction

CAS546- Distributed Systems Lecture 1 - What are Distributed Systems? What do we mean by distributed systems? * Distributed Operating Systems? * Distributed Applications? * Distributed Databases? * Networked Systems? -Wide Area? -Local Area? These are all loosely coupled distributed systems and are what we are interested in. Tightly coupled systems such as array processors i.e. those which generally share memory are of little interest on this course. The World Wide Web is very loosely coupled distributed computing environment, based on the transmission and reception of messages. Bank Automatic Teller Machines (ATM) are components of another distributed system. The Sun Operating System, Solaris is another which offers distributed file storage and process execution. ...read more.

Middle

o Access o Location o Concurrency o Replication o Failure o Migration o Performance o Scaling An Example An Air Ticket Booking System (Hypothetical) The requirements of such a system includes a high level of reliability, security against external interference and privacy of the information that the system holds. The main problems Taken from the same source. * Naming We need some means of referring to objects uniquely, wherever they are in our system. In the worst case the system could be the entire InterNet. * Communication We need a high speed communication infrastructure which supports the high level softwrae structures we use. * Software Structure - for us this will almost always be object based, though we will look at some non object based systems ...read more.

Conclusion

The Course Structure Initially we will be looking at some of the infrastructure needed for distributed systems in particular Remote Procedure Call (RPC) and its object oriented relative Remote Method Invocation (RMI). We will also look briefly at communication between processes mainly using BSD sockets. With this infrastructure we will look at the provision of distributed services e.g. Sun's Network File system (NFS). A major component of the course will be an investigation of Jini as a distributed application infrastructure and the use of this to support a high level framework such as JavaSpaces. These examples will allow us to look at the use of transactions and at design patterns or distributed systems. Other distribution mechanisms (CORBA and DCOM) will be considered in the light of the facilities provided by Jini. Finally we will discuss security issues and the provision of distributed database systems. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Information Systems and Communication section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Information Systems and Communication essays

  1. Information: G061 - Systems and Communication

    * Computer verification (double entry) - you enter the data in twice and the computer checks the entries. * Manual verification (proof reading) - you enter the data in and check manually from the screen against the source. * Lookup verification - having part of the data and retrieving the

  2. Health Book

    * Access controls - any mechanism by which a system grants or revokes the right to access some data * Encryption * Auditing - allows you to track user activity, including administrator activity * Physical security * Backup System and Generator (Tanya Beccam 2009)

  1. Database Analysis & Design

    The user requirements will be put together with the analysis to see what is needed for the new system. Non-functional requirements are involved and these are the requirements which make constraints on the design or implementation. The user requirements can be found in many different ways, * Interviews * Observation

  2. Website Design, Creation and Evaluation

    The software has clearly been developed with the future of the internet in mind, and ensures correctness of code. It also offers support for scripts, and makes it much easier for the user when it comes to CSS design. Other Options I could also use a text editor for my HTML editing purposes for instance Microsoft Notepad, or Microsoft Word.

  1. Custom Load Trucking

    The computer systems will also be able to show you exactly where the trucks are at all times so you can see exactly where there travelling. This allows Custom Load Trucking to keep an eye on its staff to make sure there working.

  2. Computer Systems

    Originally computers ran using "Command Line Interface" like DOS. In DOS the user has to know the name of every file or program they wish to run and the file path location within memory. This makes navigating through documents or opening programs slow and strenuous, for example, if a spelling

  1. ICT investigation

    Also as staff only have details on their own pupils, if a class needs to be covered then the teacher will have no details of the class What happens when new staff joins? New staff must fill out an application form including all their details, then they have a background

  2. System Analysis and Design Assignment

    The location and timing of the test - where and when the test is to be performed. C. Test Description - what the inputs will be and what the expected outputs will be. D. Test Procedures - how test data will be prepared, results obtained and analysed.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work