Downsizing : Client/Server Computing Joe Wang, The Upjohn Company, Kalamazoo, MI (616)329-8421 ABSTRACT Standardized interfaces for applications allow users to make quick transitions to Client/Server "fever" is spreading across Corporate other GUI-based applications. America like wild fire. Does your company want to get on the bandwagon? Can you really save money 2) Easy data access by using Client/Server technology? How much productivity can you gain when you migrate your The Local Area Network (LAN) provides a system to the Client/Server platform? means to connect the new generation of powerful personal workstations to other This paper gives answers to six key questions of LAN, midrange, and mainframe systems. "Downsizing". It also provides practical advises on The ability to be connected to multiple selecting a Client/Server model which best ms your platforms allows the user to transparently shop and your SAS® applications. access data residing on different platforms. Easy-to-use 4GL tools use 1) Why do you want to downsize? SOL commands as a generic means to 2) What is client/server? retrieve information or statistic, more 3) What is the best Client/Network/Server Operating quickly, allowing us to react faster to System? industry changes. 4) Is SAS portable? 5) What are the success factors? 3) Flexible system configuration 6) What are the potential problems? - With PC SAS Because of the low cost of the hardware - Without PC SAS and software of the client/server, the end user department can change/upgrade hardware and software configuration WHY DO YOU WANT TO DOWNSIZE? quickly based on the users' needs. In the past two decades, the emergence of advanced 4) User has more control personal computers and workstations, globally connected local area networks and data As technology moves processing power communications, distributed database management and applications development tools to the software, and graphical user interfaces enable many user department level, applications take companies to migrate their applications from a less development time and ongoing mainframe to client/server environment. There are support. End user departments have six major reasons for downsizing. more control on the system configuration and priority of projects. 1) Better user interface Users are now able to accomplish many Graphical User Interface (GUI) has not only made of the tasks and functions that previously software systems more user friendly, they have required the intervention of programmers. also set standards for application program interfacing. GUI provides an end user with a 5) Cost saving "point and click" type environment with pop-up menus, scroll bars, and radio buttons. Since the cost ratio of PCs and servers 1368 are dropping every year, some experts believe WHAT IS CLIENT/SERVER? that client/server computing could be half as expensive as minicomputer-based systems and 1) Definition of Client/Server one-third as expensive as mainframe computing. The key aspect of Client/Server In general, when migrating to a client/server, computing is the capability of one or more users save cost in tenms of host hardware, computers (Clients) to access (via maintenance, and licensing fees. networks) and utilize one or more computers (Servers) to perform a task. 6) Re-engineer the business process (Figure 1) In short, the server provides a service to the client. For example, the With this new enabling technology, Client/Server, clients can be 486 PCs running Windows business executives should be able to redesign 3.1 and the servers are SUN SPARC the business process to coordinate cross­ workstations running UNIX. The SUN functional workflow, infonmation technology, SPARC workstations provide printing, file people and organization, policy and regulation, management, and program execution and physical infrastructure. The end result is to services. build more flexible and effective process to deliver more value to the organization's customers. 2) Closer look While downsizing may offer more power on the There are five layers between the client desktop for less cost, most organizations still have and the server: large investments in mainframe hardware, software, and data. Many downsizing strategies do not totally Client eliminate traditional mainframe systems, but rather =========================== attempt to select the most appropriate platfonm or mix Programming interfaces of platfonms for a business enterprise. Client/Server enabling services Client/Server core services SAS* Server Communications backplane formats & Client/Server protocols Server UNIX: multi-sesslon Network transport compubng IBM*\lMICMS. singig.oossion Server .-riiting The application programming interfaces is the layer that users see and work with. Client The enabling services, such as database management, workflow routing, transaction management, and document linking, enable users to build their applications. Figure 1 Client/Server The core services provide definition, directory, and security facilities. 1369 A communication backplane deliver the content of IS SAS PORTABLE? messages between clients and servers. Examples includes remote procedure calls, X.400 Ves, SAS is portable among dtlferent electronic mail, and object request brokers. computer platfonns. Vou can port your SAS programs from a PC to a mini or a A network transport provides communications mainframe. Nevertheless, there are two between clients and servers. TCPIIP, NovelJ®s things you need to pay attention to: IPX, and IBM®>s SNA are the most popular transport. 1) MuHi-platfonn version compatibilny Surround all these layers are application Not all versions of SAS are compatible development tools and management tools. These under different operating systems. For tools allow users to manage their client/server example, SAS 608 on IBM VM/CMS is project more effectively and efficiently. compatible only with SAS 609 on SUN Solaris. WHAT IS THE BEST CLIENT/NETWORK/SERVER 2) Platfonn dependent system options OPERATING SYSTEM? Before you migrate your SAS programs to Picking the best operating system for your company's another computer platfonn, h is a good clientlserver platform can be tough and tricky practice to consolidate the platfonn especially when you plan to move mission-crnical dependent code like FilENAME, applications to this platform. When you pick the best LlBNAME, macro library, and WORK operating system, you need to pick them for the library together in one place, test the new client, the network, and the server. code on the old platfonn, move the code to the new platfonn, and change all Novell Knhwear has about 60% of the Network platfonn dependent code accordingly. operating system market. Knnwear 4.x provides robust messaging, distributed security and directory services, and the fastest file and print service and WHAT ARE THE SUCCESS FACTORS? allows users to easily manage large enterprise networks. Nevertheless, the new MicroSoft Windows In order to successfully implement a client NT 3.5 bundled wnh the BackOffice provides a server project, certain key criteria are required superb client/server support. BackOffice offers Sal as follows. Server, SNA Server, Systems Management Server, and Mail Server which based on Windows NT. More 1) Upper management support and push and more companies are migrating their Knnwear servers to NT servers. Support from the upper management is extremely important when unforeseeable Unix vendors are untlying themselves wnh the Spec technical problems are encountered or 1170, Common Desktop Environment, and better PC when the implementation slows down. connection to stay alive. 2) Top priorny project As for the best operating system for a client, there is ,V',:- no definne winner yet. OS/2 Warp 3 is more robust, Make sure your client/server projects but n only supports a subset of the Win32 API. have top priorhy. This will guarantee the Windows NT is secure and robust, but h demands at high level of support from management least 12 MB of memory. Windows 95 will run all 16- and participation from users. bit Windows application in a single address space, which makes h less robust than OS/2 and NT. 3) Parallel processes During the implementation, keep the old 1370 environment along with the new environment for character for running batch programs on performance comparisons until the new process DOS. has stabilized. 2) Slow implementation 4) Incremental release Client/Server is a new concept and Incremental release the new programming technology for programmers in many environment in order to ease the transition. company. Some programmers are not familiar with Unix or PC. When key 5) Productive project team programmers are asked to migrate their applications to this new platform, some A productive project team which consists of might respond with the following: managers, system engineers, lead analysts, and the project leader with different knowledge. a) No time to leam or migrate b) New technology is too hard to learn c) New system/technology is not robust WHAT ARE THE POTENTIAL PROBLEMS? and error-free 1) IBM/UNIX/DOS file formats incompatibility People resist changes because they feel more comfortable in the environment they This might be the most difficult problem for you to know the best and this resistance can solve if you are not aware of that IBM, UNIX, and definitely slow down the implementation. DOS have different file formats/EOl (End Of Line) characters. The following are scenarios 3) Bad vendors' technical service which might happen: In the client/server environment, You a) When uploading PC files to VM/CMS, the purchase hardware/ software products whole file may become one long record from many different vendors. When a sometimes. problem arises, the in-house Information Center and Computing Service units may b) When using the PC editor to create REXX not know the solution. The vendors' programs, the uni-REXX interpreter on Unix may technical service become vital to the not execute these programs. success of the project. c) When using the PC editor to create DOS 4) High development/maintenance cost batch programs, DOS may not execute these programs.