50-30-30 DATA COMMUNICATIONS MANAGEMENT UNIX AS AN APPLICATION SERVER IN A NETWORK OPERATING SYSTEM ENVIRONMENT Scott Koegler INSIDE Integrating with the Networking Environments, Network Server vs. Application Server, File Service, Printing across the Network, Internet/Intranet Services, Coping with a Mixed Environment INTRODUCTION Networks have evolved to become the mainstay of corporate America. Millions of personal computers are connected to network servers run- ning applications ranging from personal productivity to corporate ac- counting, yet the demands on the network continue to increase. These demands typically take two forms. The first is the availability of applica- tion software specifically tailored to the operations of an organization. The second is the need to run processor-intensive applications in a per- sonal computing environment. Both of these situations require in- creased horsepower from individual computing components, and in some cases the required horsepower is just not available from net- worked components. Today’s network architectures have been maximized to provide su- perb performance for file and print sharing tasks, but still may not always offer the level of performance required. Although the network operating system can provide network servic- es, it is not typically optimized for PAYOFF IDEA application processing. Even in those Today’s distributed systems can become highly cases where an application can be complex even when the network is homoge- run on a network server, doing so neous. Maintaining a consistent NOS environ- may degrade the performance of the ment lets network administrators develop a depth entire network, making the proposi- of understanding that often leads to better effi- ciencies in both day-to-day operations and in tion counterproductive. troubleshooting. 06/98 Auerbach Publications © 1999 CRC Press LLC Even with the stunning advances in hardware systems and program- ming techniques, many companies find that the specific applications that fit their operations were created to run in multiuser environments rather than in network environments. In many cases this is the result of migrat- ing an application from a mainframe system and resulting programs re- main optimized for the multiuser rather than networked systems. IS UNIX STILL GOOD FOR ANYTHING? UNIX has a long history in the computing world. The simple fact that it is still around must mean more than that it is just hanging on. In fact, UNIX has enjoyed a resurgence of interest over the last couple years, largely because of the growth of the Internet. But UNIX has other strengths beyond the Internet. The original advantages of UNIX were with its file system, multitask- ing kernel, and easy configurability. None of those early considerations have deteriorated, and they are still not fully duplicated in the newer op- erating systems. To be sure, both NetWare and NT have advantages with regard to market availability, commercial support, and a wide range of software options, but the basics still can be filled easily and inexpensive- ly with UNIX services. UNIX is a mature operating system and has been fairly well debugged and enjoys a wide, mostly independent, support group via the Internet. Its scalability, as of this writing, puts NetWare and NT Server in the little leagues. INTEGRATING WITH THE NETWORKING ENVIRONMENTS Networks have become commonplace, and the architecture has em- braced Ethernet as the predominant standard. Novell NetWare continues to maintain a 60% plus share of network server installations, and Mi- crosoft NT server continues to build an increasing market share. In the past, these operating systems imposed their own network protocols on their environment. Customer demand forced simplified integration, and both vendors supplied solutions and the third-party solutions, but the connectivity was generally less than seamless. The stunning rise in pop- ularity of the Internet and its associated TCP/IP protocol has had the ef- fect of forcing these two major network operating system suppliers to support this protocol as a ground-leveling standard. The net result to the user is that both Novell and Microsoft now supply the TCP/IP protocol as a part of their base product offering. In fact, Novell now offers TCP/IP as a selectable replacement for its long-standing IPX protocol. What this means in a practical sense is that it is easier than ever for an organization to implement easily a variety of operating systems based on its business needs and application requirements rather than on what the net- working vendor’s dictates. It is now commonplace to find a corporate IT shop with a mixture of Novell and Microsoft servers on the same network. WHY BOTHER WITH ANOTHER OS? Although NetWare is a highly efficient file and print server, with Internet services included as part of the file server function, it does not offer the application services available in Windows NT. NT can provide a combi- nation of file and print services along with robust application service support and Internet services as well. UNIX can supply nearly all the same facilities, and with TCP/IP now a networking mainstay, integrates into the LAN environment almost with- out being noticed. But, because there are few practical differences be- tween the available solutions, there needs to be some compelling reason to increase the complexity of the corporate LAN, even if only marginally. The most often cited reasons for installing a UNIX server in a LAN en- vironment fall into two categories: application support and price. In short, if an application is only available as a UNIX application, the choice is reduced to finding an application that runs on the existing network or installing the necessary UNIX resources. Organizations have somewhat more flexibility when installing a new application than when trying to in- tegrate a legacy system into a LAN environment. The good news in either of the situations is that connecting an existing UNIX application to a net- work is likely to be easier than either converting the function to a differ- ent application that is LAN based or redeveloping the application to run on the LAN. The combination of Windows and a good terminal emulator can deliver a very powerful combination that leverages the strengths of all the available applications and operating systems. The second powerful consideration in favor of UNIX is the wide range of vendors offering similar versions of the same operating system. A by- product of this competition is the availability of highly competent operat- ing systems at very low prices. This is not to say that all UNIX OSs are the same. Some proprietary versions, like the IBM AIX and the DG version, weigh in at the same or greater costs than the popular Network Operating Systems (NOS). But at the other end of the range are systems like the SCO UNIX and, at the extreme low end, the Calera Linux. To be sure, there are differences in the variations in both capabilities and support, and these differences need to be factored into any decision, but depending on the level of in-house expertise, nearly all can be viable solutions. One of the other things that can provide a benefit in the UNIX envi- ronment is the existence of a mature and widespread user-support com- munity. The UNIX community has been the premier example of noncommercial systems development for many years. Programs ranging from small utilities to full applications and even the operating system it- self have been available through the efforts of programmers around the world. Possibly the best example is the Linux version of UNIX, which was developed by a loosely coordinated group of programmers who each contributed his or her efforts to developing a state-of-the-art OS that is available, complete with source code, simply by downloading it. The commercial versions of Linux add several features that make this user- supported system viable in a corporate environment. But at under $500 for a full license, it is a tough competitor. OPERATIONAL CONSIDERATIONS The introduction of multiple hardware and software platforms into a computing environment is a normal, if unwelcome, reality. It increases the range of knowledge required for internal support and adds to the list of vendors involved in the organization and, because of these factors, should not be entered into simply for the sake of adding a new environ- ment. However, given a valid business reason for doing so, there are tools and systems that minimize the impact. Modern IT systems provide increased management capabilities through a variety of facilities. The availability of the Simple Network Management Protocol (SNMP) has made the management of heteroge- neous networks possible by providing a common protocol that nearly all system software and hardware vendors have implemented. With this kind of consistency, it is now possible to view a range of network servic- es through a common console. This means that the differences in man- agement of various platforms are minimized through the common interface. Day-to-day activities can be incorporated into a centralized sys- tem that decreases the load on the IT staff and reduces the integration of yet another operating system into a routine function. NETWORK SERVER VERSUS APPLICATION SERVER The role of the server needs to be taken into consideration when con- templating adding computing resources. In fact, one of the main reasons for adding a UNIX server to an existing networked environment is the different function the server will fill. In a typical networked environment, the processing load is distributed, not always evenly, across the client PCs, the server, and the network ca- ble. Client/server systems attempt to do a better job at this load distribu- tion, but these systems have never really delivered on their promise of low cost, quick development, and high performance.