Chapter 2 pg 70: 1, 2, 7, 10, 11, 12, 13, 16, 19, 20, 26
1. What are the different types of application architectures? There are three different fundamental application architectures. In host-based networks, the server performs virtually all of the work. In client-based networks, the client computer does most of the work; the server is used only for data storage. In client-server networks, the work is shared between the servers and clients. The client performs all presentation logic, the server handles all data storage and data access logic, and one performs the application logic. Client server networks can be cheaper to install and often better balance the network loads but are far more complex and costly to develop manage. 2. Describe the four basic functions of an application software package. Basic functions of an application Layer
Storing of data generated by programs (e.g., files, records) Data access logic
Processing required accessing stored data (e.g., SQL)
Business login such as word processors, spreadsheets
Presentation of info to user and acceptance of user commands 7. Compare and contrast two-tier, three-tier, and n-tier client-server architectures. What are the technical differences, and what advantages and disadvantages does each offer? Two-tier client server architecture uses only two sets of computers, one set of clients and one set of servers. Three-tier architecture uses three sets of computers. In this case, the software on the client computer is responsible for presentation logic, an application server is responsible for the application logic, and a separate database server is responsible for the data access logic and data storage. Coming to n-tier architecture uses more than three sets of computers. In this case the client is responsible for presentation logic, a database server is responsible for the data access logic and data storage, and the application logic is spread across two or more different set of servers. The primary advantages of an n-tier client-server architecture compared with a two-tier and three-tier is that it separates out the processing that occurs to better balance the load on the different servers; it is more scalable. We have three separate servers, which provides more powerful server, or even put in two application servers. The primary disadvantages to an n-tier architecture compared with two-tier and three-tier architecture, it puts greater load on the network. It generates more difficult to program and test software in n-tier architectures than in two-tier architectures because more devices have to communicate to complete a user’s transaction.
10. What do the following tools enable you to do: the web, e-mail, FTP, telnet? Web
One of the fastest growing Internet applications is the web. It began with two innovative ideas: -Hypertext
A document containing links to other documents
-Uniform Resource Locators (URLs)
A formal way of identifying links to other documents. E-mail
Electronic mail was one of the earliest applications on the Internet and is still among the most heavily used today. With e-mail, users create and send message to one user, several users, or all users on a distribution list. File Transfer Protocol (FTP)
FTP enables you to send and receive files over the Internet. FTP works in a similar manner as HTTP. FTP requires an application layer program on the client computer and a FTP server application program on a server. Telnet
Telnet enables users to log in to servers (or other clients). Telnet requires an application layer program on the client computer and an application layer program on the server or host computer. 11. For what is HTTP used? What are its major parts?
The standard protocol for communication...