Questions
Q1. What are the different types of application architectures?
A1. There are five different application architectures which are as follows:
Host-based Architecture:
This was the very first communication network that was developed. Here all the functions such as data storage, data access logic, application logic and presentation logic is performed at the host server. Basically, the terminals allow users to receive and sent messages from the host computer. The client has to send the captured keystrokes to the server. The server then undergoes processing and sends the instructions about what should be displayed back to the client.
Client-Based Architecture:
In this architecture the application software at the client’s end is responsible for application logic, presentation logic and data access logic. The server is responsible only for data storage. Here all the processing takes place at client side except that the data is stored at the server side.
Client-Server Architecture:
This architecture attempts to maintain the balance of processing between server and client by having each of them do some work of the logic. Here the server is responsible for data storage and data access logic whereas client is responsible for presentation logic. The application logic may be at the server or at the client side, or split between two.
Cloud-Based Architecture:
In cloud based architecture because they outsource all or part of infrastructure to firms that specializes in managing that infrastructure. These further can be categorized such as software, platform and infrastructure.
Peer-to-peer Architecture:
In this architecture, all the computers act as a server and a client. So, all the computers perform the four functionality that are: data storage, data access logic, application logic and presentation logic.
Q2. Describe the four basic functions of an application software package?
A2. The four basic functions of an application software package are:
Data Storage: This basically related to data storing and retrieving. As most of the organization rely on data, it has become important to efficiently store data for easy access.
Data Access Logic: This deals with the processing part that is required to access the data. This often means database queries in SQL.
Application Logic: Sometimes this is referred to as business logic. According to the requirements of an application, this logic works for maintaining coordination of infrastructure domain and components.
Presentation Logic: This deals with presentation of the information to a user. It also involves acceptance of user commands. It deals with how the business objects will be displayed to the user of a software.
Q3. What are the advantages and disadvantages of host-based networks versus client-server networks?
A3. Host-Based Network:
Advantage- This kind of architecture is very simple and works very well as all the application software and data is stored on one server. The other advantage is that there is single point of control as all messages go through one central server.
Disadvantage: Since the server has to process all the messages, so as the number of network application grows, the servers become overloaded and becomes inefficient in processing the user demand quickly. As response time slows, network management spends a lot of money in upgrading. This expensive upgradation is another problem with host-based networks.
Client-Server Network:
Advantage: This kind of architecture is more efficient than the host-based architecture as the functionalities of software package gets distributed between the host and the server. Apart from distributed processing, it even allows combined usage of software and hardware from different vendors. And last less bandwidth is required for this.
Disadvantage: There are challenges in configuration of software and hardware from different vendors to work altogether. To overcome this, then we require a middleware. In case of tired architecture, we face another issue of increased network load and more complexity. Finally, in this it becomes difficult to develop applications.
Q7. Compare and contrast two-tier, three-tier, and n-tier client-server architectures. What are