E-Business Lecture 3 Flashcards
Name the 4 different layers of infrastructure for e-Business
- Bottom layer (network topologies, the internet and protocols such as TCP/IP
- Basic Infrastructure layer (contains client/server and tiered architecture
- Technologies required for web-based applications
- Collaborative technologies (such as workflow systems & EDI
What is client server computing?
It handles the need for both centralized data control and widespread data accesibility
What does the client/server model provide?
A typical way to interconnect programs that are distributed across different locations
In which 2 ways can processing tasks be divided between the client and the server?
- Thin clients, with heavy servers
2. Servers that only contain common data with all the processing executed at the level of the client
What are the 5 basic features of the client/server model?
- Clients and servers are well defined interfaces
- Each client/server relationship is established between two functional modules, where one module, the client, initiates service requests and the other module, the server responds to these requests
- Information exchange between clients and servers are strictly through messages
- Message exchange is typically interactive
- Clients and servers may run on separate dedicated machines connected through a network
What do the tiers of an server/client architecture represent?
Refer to the number of elements into which the application is partitioned, not the number of platforms where the executable is deployed
What are the 5 drawbacks of the 2-tier client/server architecture?
- Scalability problems
- Poor business logic sharing
- Client reliance on the database structure
- Limited interoperability
- High-maintenance costs
In what tiers is the three-tier architecture partitioned?
- Presentation tier
- Processing tier
- Data tier
What does the processing tier enable?
It enables developers to isolate the main part of an application that can change over time: data & relationships inherent in the data
Name 3 varieties of ways to implement the middle tier in a three-tier architecture?
- Transaction processing monitors
- Message servers
- Application servers
What do websites do?
They provide the content that is accessed by web users. A web site is a catalogue of info
For each content provider over the web, what is necessary?
- Web server
- Content files (web pages)
- Gateways (programs that access non-Web content e.g. databases)
Definition of “Web Server”
An application that receives calls from Web clients and retrieves web pages and/or receives information from gateways
What is a web browser?
Web browsers are the clients that typically use graphical user interfaces to wander through the websites
Name the 2 distinguishes of web applications
- Static documents delivered from the file system of the web server
- Dynamic documents that have an interactive and usually time-sensitive nature. These require the server to generate the document on the fly