Mainframes Strengths vs. Client/sever strengths By: Priscilla Rojas Mitchell Evans Peter Caccamo

Mainframes Mainframes were one of the first computers used by businesses; they are capable of processing millions of instructions per second and have access to trillions of characters of data. Mainframes are used by large and medium-sized companies such as banks, insurance companies, and manufacturers, to process large amounts of data quickly. Mainframes cost more than $1 million and debuted over 50 years ago. The majority of mainframes made today are from IBM corp. and continues to be hugely reliant on them. Mainframes used to be defined by their size, and they can still fill a room, cost millions, and support thousands of users. But now a mainframe can also run on a laptop and support two users. So today's mainframes are best defined by their operating systems: Unix and Linux, and IBM's z/OS, OS/390, MVS, VM, and VSE. Mainframes combine three important features: 1) Reliable performance, which is essential for reasonable operations against a database. 2) Maximum I/O connectivity, which means mainframes excel at providing for huge disk farms. 3) Maximum I/O bandwidth, so connections between drives and processors have few choke-points.

Mainframes

SpeedServe Online bookseller to Amazon.com; expects to process >1 million transactions per day Based in La Vergne, Tennessee Maxed out Windows NT server with 500,000 book titles; 85,000 videos; and 15,000 games Chose to invest in IBM S/390 mainframe SpeedServe has lowered labor and support costs, eliminated hardware and networking issues, and is currently only employing 3 of the mainframes 10 computers

Merrill Lynch & Co. Runs crucial stock market data website on their 10- engine Amdahl Corp. mainframe Employs IBM VM Operating System In 1998 was averaging 18 million hits per year Use of a mainframe allows Merrill Lynch to link constantly updated stock info all of the companies internal users, clients, and external web users

Client/server Client-server computing is very popular in companies where many users work together. It is a very powerful tool in connecting supporting multiple users. Client/servers take up a lot less room, cost is cheaper, and is more economical. Client/server describes the relationship between two computer programs in which one program, the client, makes a service request from another program, the server, which fulfills the request. The client/server model has become one of the central ideas of network computing. Most business applications being written today use the client/server model. Typically, multiple client programs share the services of a common server program. Both client programs and server programs are often part of a larger program or application.

CLIENT / SERVER 5.32

Bass Beer Located Staffordshire, England, they are a multi- national corporation, which includes sub-division such as Bass Brewers, Bass Taverns, Bass Soft Drinks, Bass Leisure and Holiday Inn Worldwide In 1988, they decided that the current computer situation was not working out and made the decision to switch from mainframes to client server. Before the switch they operated on many mainframe based dumb terminals, and many of their systems could not communicate with each other and consequently arise situations within the company

Solutions Bass management created central information technology committee. The goals of this committed were: 1. Taking advantage of bulk purchasing of information technology 2. Setting corporate wide hardware and software standards 3. Creating long-term business partnerships with IT suppliers 4. Establishing a system that connected company in a seamless way Basically, they wanted to universalize the system

Results Limited business with IBM, Unisys for hardware; Novell for networking and Microsoft corp. for desktop software. They now employ more than 200 IBM AS/400 minicomputers and 4500 PC all linked by client server environment They were able to cut their IT staff from 1300 to 850; over half which were new to the company.

Mainframes vs. Client/servers Mainframes are replacing client-servers. They provide more horsepower for high volume transactions, and have more storage space than a server would have. Although mainframes are more expenses they are said to be more reliable. A disadvantage of a mainframe is that everything is held on the Mainframe - if the network is out or too many users logged on, there is nothing you can do. In Client/Server (normally) all the computing happens at the users end i.e. on their own PC ('Client'). The 'Server' is used mainly for file & data storage and other 'common' resources (such as Printer & www access). So the Server has to check that the users have access rights & permissions to the data (e.g. s) and resources.

Mainframes vs. Client/servers An advantage of a server is that you can work 'off-line' and only need to 'log-on' when you need access to common resources. Also you can have many users logged on at once, unlike companies that runs on a mainframe.

References Case study articles: SpeedServe and Merrill Lynch: Mainframes as electronic commerce web servers IBM still bangs profit out of mainframe business Bass beer servers as Client/Server environment Yahoo Images Yahoo Search engine Mainframes.com (trademark and copyrights owned by IBM) Online textbook (topic 4)