The main contents of this chapter include all of the following: Multiprocessor architectures, client-server architectures, distributed object architectures, inter-organisational computing. | Distributed Systems Architectures Objectives To explain the advantages and disadvantages of different distributed systems architectures To discuss client-server and distributed object architectures To describe object request brokers and the principles underlying the CORBA standards To introduce peer-to-peer and service-oriented architectures as new models of distributed computing. Topics covered Multiprocessor architectures Client-server architectures Distributed object architectures Inter-organisational computing Distributed systems Virtually all large computer-based systems are now distributed systems. Information processing is distributed over several computers rather than confined to a single machine. Distributed software engineering is therefore very important for enterprise computing systems. System types Personal systems that are not distributed and that are designed to run on a personal computer or workstation. Embedded systems that run on a single processor or on an . | Distributed Systems Architectures Objectives To explain the advantages and disadvantages of different distributed systems architectures To discuss client-server and distributed object architectures To describe object request brokers and the principles underlying the CORBA standards To introduce peer-to-peer and service-oriented architectures as new models of distributed computing. Topics covered Multiprocessor architectures Client-server architectures Distributed object architectures Inter-organisational computing Distributed systems Virtually all large computer-based systems are now distributed systems. Information processing is distributed over several computers rather than confined to a single machine. Distributed software engineering is therefore very important for enterprise computing systems. System types Personal systems that are not distributed and that are designed to run on a personal computer or workstation. Embedded systems that run on a single processor or on an integrated group of processors. Distributed systems where the system software runs on a loosely integrated group of cooperating processors linked by a network. Distributed system characteristics Resource sharing Sharing of hardware and software resources. Openness Use of equipment and software from different vendors. Concurrency Concurrent processing to enhance performance. Scalability Increased throughput by adding new resources. Fault tolerance The ability to continue in operation after a fault has occurred. Distributed system disadvantages Complexity Typically, distributed systems are more complex than centralised systems. Security More susceptible to external attack. Manageability More effort required for system management. Unpredictability Unpredictable responses depending on the system organisation and network load. Distributed systems architectures Client-server architectures Distributed services which are called on by clients. Servers that provide services are treated differently from .
