Distributed Systems

In: Computers and Technology

Submitted By francelyno
Words 38975
Pages 156
Distributed Systems: Concepts and Design
Edition 3

By George Coulouris, Jean Dollimore and Tim Kindberg Addison-Wesley, ©Pearson Education 2001

Chapter 1
1.1

Exercise Solutions

Give five types of hardware resource and five types of data or software resource that can usefully be shared. Give examples of their sharing as it occurs in distributed systems. 1.1 Ans. Hardware: CPU: compute server (executes processor-intensive applications for clients), remote object server (executes methods on behalf of clients), worm program (shares cpu capacity of desktop machine with the local user). Most other servers, such as file servers, do some computation for their clients, hence their cpu is a shared resource. memory: cache server (holds recently-accessed web pages in its RAM, for faster access by other local computers) disk: file server, virtual disk server (see Chapter 8), video on demand server (see Chapter 15). screen: Network window systems, such as X-11, allow processes in remote computers to update the content of windows. printer: networked printers accept print jobs from many computers. managing them with a queuing system. network capacity: packet transmission enables many simultaneous communication channels (streams of data) to be transmitted on the same circuits. Data/software: web page: web servers enable multiple clients to share read-only page content (usually stored in a file, but sometimes generated on-the-fly). file: file servers enable multiple clients to share read-write files. Conflicting updates may result in inconsistent results. Most useful for files that change infrequently, such as software binaries. object: possibilities for software objects are limitless. E.g. shared whiteboard, shared diary, room booking system, etc. database: databases are intended to record the definitive state of some related sets of data. They have been shared ever…...

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