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Lecture Business system development - Lecture 19: Designing distributed and internet systems

Lecture 19 - Designing distributed and internet systems. We today’s lecture we will: Define key client/server, LAN, distributed database, and middleware terms; distinguish between file server and client/server environments; describe alternative distributed system designs. | Business System Development CSC581 Lecture 19 Designing Distributed and Internet Systems 2 Summary of the previous lecture In previous lecture, we : Discussed the GUI and the Dialogue Discussed how design specifications vary based on system development methodology. Defined quality requirements and write quality requirement statements. Read and understand a structure chart. Explained the roles of prototyping and CASE tools in design specifications. Discussed the application of design specifications to Agile Methodologies. Outlines We today’s lecture we will: Define key client/server, LAN, distributed database, and middleware terms. Distinguish between file server and client/server environments. Describe alternative distributed system designs. The Process of Designing Distributed Systems Similar to designing single-location systems Due to multi-location deployment, numerous design issues must be considered More opportunity for failure due to number of components Main issues involve . | Business System Development CSC581 Lecture 19 Designing Distributed and Internet Systems 2 Summary of the previous lecture In previous lecture, we : Discussed the GUI and the Dialogue Discussed how design specifications vary based on system development methodology. Defined quality requirements and write quality requirement statements. Read and understand a structure chart. Explained the roles of prototyping and CASE tools in design specifications. Discussed the application of design specifications to Agile Methodologies. Outlines We today’s lecture we will: Define key client/server, LAN, distributed database, and middleware terms. Distinguish between file server and client/server environments. Describe alternative distributed system designs. The Process of Designing Distributed Systems Similar to designing single-location systems Due to multi-location deployment, numerous design issues must be considered More opportunity for failure due to number of components Main issues involve ensuring reliability, availability, survivability, performance 6 Deliverables and Outcome Document that consolidates system design information: Description of each site Description of data usage for each site Description of business process for each site Contrasts of alternative IS architectures for site, data and processing needs of each site 7 Designing Systems for Local Area Networks (LAN) LAN: the cabling, hardware, and software used to connect workstations, computers, and file servers located in a confined geographical area Main LAN configuration options File Server architecture Client/Server architecture File Server Architectures A device that manages file operations and is shared by each client PC attached to a LAN DBMS use in a file server: One copy of the DBMS is on the file server and concurrently running copies are on client PCs. All data manipulation is performed on the client PC. Limitations of File Servers Excessive data movement Entire data tables must be transferred .