Comparison Between Mainframe And Distributed Information Technology Essay

Comparison Between Mainframe And Distributed Information Technology Essay Client-server invent has actual and instant profits to software developers, apart from the volume of system. The client-server model is accepted model which operates client and server machines which are designed for exact purposes for computer networking. The Internet and Local Area Networks (LANs) both can use client-server model. Examples of the client-server systems on internet could be Web servers and Web browsers, FTP clients and servers, and DNS (Domain Name System). In FTP, users enter a computer name or sometimes an IP address in interface to locate connections to the server. There are two split devices in client-server model which are personalized for their considered reasons. For instance, a network client works most excellent in a big screen display, whereas a network server does not require any display and can be placed wherever in the world. On the other hand a device can be used as both, a client and a server for identical purpose. Similarly, a server device for one app lication can concurrently work as a client to other servers, for changed applications. People like client-server architecture because it offers error separation between modules, scalable performance in multiple servers, and central server is easy to manage and easy to program. The problem described in the assignment question says that in 1987 Hures implemented its first information system which was in mainframe computer that served Altos terminals to the users desktop. Then they ported the application on the client/server network to keep pace with changes in both the business and information system environment. Although the company started to grow non-stop, they noticed the following problems: Difficulty in scaling the servers to respond to the increased load in the distributed environment. Continual requirement for increasingly powerful desktop machines. But the main problem faced by Hures was as follows: Difficulty in configuring application into client-server modules. Modifying the configuration in response to user feedback. Analysis: Client/Server Devices: Long time ago as PCs (Personal Computers) turn out to be option to older mainframe computers, Client/server networking model developed in fame. The devices which ask for and accept information over the internet is Client PCs with network software applications established. Client functions can be found in mobile devices and desktop computers. Files and databases plus composite applications such as websites are stored in server device. High performance central processors, larger disk drive and more memory than clients are needed in server devices. Client/Server Applications: Applications and devices are differentiated by the client-server model. Client devices request a server side via posting messages in networks, and those servers reply to their clients with proceeding on those requests and sending back outcomes. According to about.com one server generally supports numerous clients, and multiple servers can be networked together in a pool to handle the increased processing load as the number of clients grows. Suggested solution for Hures problems: Here the problems faced by Hures are unique as my understandings. The described problem relates on the speediness of the system. The system should be created as which can handle upcoming demands or requirements of the business. According to this, the corporation or the designer of the system would not have concentrated on the upcoming development of the adjustment of the system or the system itself, to make sure that the system will give the future requirements and demands because of the various alteration in both external and internal situation that can vary the whole flow of information in the corporation. The bigger centre of attention should be the customer, and accordingly on the information resources and services that are needed to maintain communication with customers. So the information system should be created which can support the future demands, requirements and also support the user communication. Client Server Architecture: Nowadays client-server architecture is flexible in rapidly altering IT landscape. It relies on messaging services for interaction between components and is modular in structure as well. It is actually considered for improving usability, flexibility, interoperability, and scalability. Usability means the capability of the C/S architecture to achieve customers objective which is the part of human computer interaction. An obvious consistent process of evolution towards an objective and ease of use could be considered as some of the defined features. Term flexibility offers a better key space than that reachable with single computer models and it means C/S architecture is capable to change according to different users and various system requirements. Scalability is very important term for C/S architecture which refers to a products capacity to modify in size or amount kindly to meet up requests from users. Interoperability is ability to utility with other systems with no involving person involvement and manpower. Efficiency in all of these above features can be improved through improvements by client-server architecture. According to Chris Loosley and Frank Douglas client server architecture has following primary qualities: Systems are created by collecting independent components which gives unique and specific functions to system. Client components relate with users and servers to manage computing resources in the easiest arrangement where in more difficult arrangements, some servers can also be clients of other servers. Clients and servers can use hardware and software uniquely suited to the required functions. Front-end and back-end systems usually need computing resources that differ in type and power. C/S architecture is expanded due to the limits of file-sharing architectures that needs loads of bandwidth and sometimes it may stop or jam a network reasoning it to collapse. Only low shared usage and low volume of data can be transmitted. The file servers are replaced with database servers in C/S architecture and RDBMS (Relational DBMS) answers user queries and also improve consistency of data between different users so every user can have right to use the equal updated information. Till now only particular queries were being answered so the data of the file transferred in place of the whole file which reduces speed of the network. Client/Server with Database servers is shown below: Client Application Network Client Application Client Application Database Server Figure 1: C/S architecture with Database server C/S Architecture in Mainframe Environment: The design of complex mainframe by using modular programming and the association of modules into consistent groupings, or layers, has been a standard practice from long time. Layering is good design practice. In mainframe environment host computer (a mainframe) levers all processing, counting input, output, data storage and retrieval and that was being used in 70s. No matter what the target environment, specialization of function within distinct layers encourages designers to keep similar functions closely aligned, from both a functional and a performance viewpoint (Chris Loosley and Frank Douglas 1998, pp.30) thats why layering is good practice. C/S architecture in mainframe environment with file server is shown in the following figure: Client Application Network Client Application Client Application Figure2: Client/Server with file servers in mainframe environment. C/S Architecture in Distributed System: In distributed system number of computers (workstations, PCs) is distributed physically and connected by a communication network which handle all processing and are being used by the todays generation. The coverage is not nearly as absolute as in mainframe environment. For distributed systems, the coverage is not nearly as complete as it is in a mainframe environment. Distributed system became famous when a client posts a request and gets any service that did not appear from nowhere. Client/server model a lot referred to as a two-tier model which is related with tiny LAN-based distributed systems. But architecturally, it originated from software engineering principles developed for usual, centralized mainframe systems. Client Application Network Client Application Client Application File Server File Server Figure 3: Client/Server with file servers in distributed environment. Comparison between Distributed and Mainframe: The following figure shows comparison between distributed system and mainframe environment system and the difference of layering in between those two: Figure 4: Functional layering in mainframe and distributed systems (Chris Loosley and Frank Douglas, 1998) 2. Alternative Architecture for Hures: To solve the problem faced by Hures current client/server technology, Client-Queue-Client can be useful as alternative architecture. This uses a passive queue which allows the client instances to communicate directly with each other, which will refine their request from the services (Exforsys Inc). It helps out to maintain and avoid any inconveniences with the server so it could be helpful for Hures to use this architecture as alternative. To track the number of clients that are connected to the server, client queue is utilized. Therefore, the server can trace which resources the client has obtained, and the server can release the resources after the client connection breaks down (Chan Leong 2003). Scalability is very important feature which take part in Client/Server architecture effectively. Nowadays enterprise systems must accommodate growth. As the information systems grow, performance problems take place alongside six different dimensions; those are databases, stored objects, user population, transaction rates, data analysis, and networks. Good design anticipates the effects of business growth on performance. To shorten debate of performance, one of these dimensions is considered individually from each other. In any actual enterprise, some relationships will usually be real amongst these four effects for example, complex networks typically host large client populations, and a high transaction rate generally implies a large client population. However, such relationships are not necessary. Compared to the mainframe environment, client/server gives enhanced scalability since connections can be made as required rather than being set. More and more servers can be included to a network since application needs raises. Though, the increase in power will not be linear in terms of the number of servers. Intranet web Technology: Intranet is a web technology which is constructed by applying similar protocols and tools those are applied by the global internet but only difference is the internet is applied to the different place in the world and intranet is applied to the internal network such as in organisation. It can be described like a closed-circuit television system, which can be viewed only by those people within the organization that owns the system (Lowe 2009). Intranet site could only be viewed by those who are within that network of that particular organisation. Even though based on the same protocols as the World Wide Web, an intranet is protected from the outside world either by not being connected to the outside or through a series of hardware and software obstacles known as a firewall (Matthews Matthews 2003, p. 64). Advantages of Intranet: Intranet could be huge method of making available information to the internal users of the organisation and that can be the key benefit of the intranet. The applications which are used for newsletters, price lists, policy manuals etc. might be published by using intranet web technology. It can also help to transact application by gathering information that is related on expense and programs (Lowe 2009). Since intranet permits to make a personal position in the Internet, the position will be protected and safe, because only those persons with abilities to access can make use of the website over the Internet. Most of all, it can facilitate to distribute information to the users in more easier and effective manner. Intranet also gives increased productivity, reduced margin of error, flexibly; it has appropriate and accurate information, and lets smaller for marketing. Disadvantages of Intranet: Intranet web technology can be expensive to set up and maintain within the organisation because it could require extraordinary team for managing the process of allocating and maintaining the resources which are occupied in the website. If the access is got by someone else on the outside of the organisation it can be risky for the company so there could be some security issues might be raised. For instance, an employee might have posted sensitive information for all employees to see. Intranet is the technology which could need upgrades and might not have software compatibility and security features can be insufficient as well. Sometimes poor user support may not be effectively scale up. If some users may not have PCs at their desk, they could not be able to access the intranet. There can be possibilities of information overload which can happen when the big amount of data has been put on the intranet and that can make very difficult for employees to find the way and find data that is meaningful or that they need. With Intranets, firms have to set up and maintain separate applications such as E-mail and Web servers, instead of using one unified system as with groupware that is less back-end integration7. Intranet software and the internet: There is no uncertainty that intranet software is measured as one of the most taken advantage of networking technology in the business world. The previous sentence becomes true because it can give various advantages which cannot be achieved by the peer-to-peer and client-server architecture. It permits companies to obtain improvement of the wireless and Internet technology, and on top of that, it gives the privacy and security which can be presented by established client/server system. As a result of this, it has been seen that the attractiveness of intranet software and the Internet pose threats towards the traditional client/server systems. However, it is significant to think about that although intranet and the Intranet are being exercised and conventional worldwide, there are still fractions or characteristics of the company which are in necessitate of using the established client/server systems. Conclusion: To conclude that client/server architecture is the well known and well established network model which is used a lot nowadays. It gives more scalability, flexibility, usability, interoperability which improves the efficiency of the network and throughput as well. As we know there could be some problems with system and tools which are provided but as long as we consider that the problems could be solved with the C/S architecture that is main advantage of the C/S architecture. In the report client/server architecture is explained and we compared the C/S architecture in both mainframe environment and in distributed environment. The arrangements of the mainframe and distribute systems are explained in order to C/S architecture so from that we can figure out how the client/server model will suit the different environment. As we discussed there are some issues raised about C/S architecture used in the information systems which was developed for the Hures and it was in mainframe environment so in place of that distributed systems can be used to solve the problem and also the alternative solution for the C/S architecture can be considered to solve the problem of Hures. References: About.com: Wireless/Networking (2010) Introduction to Client Server network [Online], Date of retrieval: 29/01/2010, Available from: http://compnetworking.about.com/od/basicnetworkingfaqs/a/client-server.htm Chris Loosley and Frank Douglas (1998), High performance, client/server, (pp. 38-40), John Wiley Sons. Chan, A T S Leong, H V 2003, Cooperative Internet Computing, Springer.   Exforsys Inc. (2000-2010) Peer-to-Peer and Client-Queue-Client Architecture [Online], Date of retrieval: 03/02/2010, Available from: http://www.exforsys.com/tutorials/client-server/peer-to-peer-and-client-queue-client-architecture.html Lowe, D 2009, Networking for Dummies, For Dummies. Matthews M Matthews (2003), Microsoft Office FrontPage 2003: The Complete Reference, McGraw-Hill Professional. Ravi Kalakota Andrew B. Whinston (1997), Electronic Commerce, pp.88-90, Addison Wesley Longamn, Inc.