If you are creating e-business applications, whether from scratch or by extending existing AS/400 applications, you to need to start shopping for a Web application server. The nascent market for Web application servers is evolving fast, and several different styles are already available for use with AS/400s. Although these servers help insulate e-business application programmers from the complexity of creating Web-enabled applications, choosing one is no easy task.

If you intend to build e-business applications—meaning extended legacy as well as brand-new intranet, extranet, and Internet Web-style applications—you’re probably shopping for a Web application server. Depending on which analyst you ask, anywhere from 25 to 50 companies claim to sell Web application servers of one sort or another. Four vendors—IBM, BEA Systems, Bluestone Software, and Novera Software—sell Web application servers for the AS/400, and since the AS/400 supports Java, dozens will likely follow in the coming year.

What exactly are Web application servers, and why do you need one? Those questions require complex answers, as you would expect from the organic phenomenon of e-business, which draws on all the best old and new computing ideas to solve complicated information technology (IT) problems.

Web application servers have their roots in client/server computing, oddly enough. Before client/server computing took off in the early 1990s, applications were, by and large, simple green-screen, text-based systems controlled entirely by the server. Server processing power was expensive and green-screen clients were (supposedly) not as sophisticated as intelligent graphical clients. Client/server tools allowed IT organizations to bring more functionality to their corporate applications by using relatively cheap PCs to handle some online transaction preprocessing and a lot of the graphical operations for applications.

Early client/server products used a two-tier architecture: a server and a client, usually linked by a local area network. More times than not, these products involved screen scraping, the process of giving server applications a GUI makeover by painting pretty

pictures on top of standard terminal emulation of application green-screens. In the case of the AS/400, early client/server computing meant running Windows-based 5250 terminal emulation software and perhaps linking an RPG or COBOL application to a word processor, a spreadsheet program, or a homemade PC-based interface for that program written in a visual programming language like C or Smalltalk.

As client/server evolved, a number of tools went beyond screen scraping to actually reimplement AS/400 application screens in a native PC format with hooks back into the AS/400. Companies could completely revise the interfaces to their applications and databases using tools such as IBM’s VisualAge for RPG or Microsoft’s Visual Basic. N- tier computing, the last improvement in client/server technology, hit just as the Web started to take off in 1995. This new application deployment method separated databases from the application logic that manipulated those databases. As processing requirements increased on either the database or application tiers, companies could just add more servers to pick up the load. SAP’s R/3 was an early N-tier application, and most enterprise resource planning (ERP) packages today use an N-tier architecture.

While the N-tier client/server approach, in theory, allowed companies to build mainframe-class, scalable, and reliable applications running on less impressive midrange servers in the mid-1990s, only companies as big as SAP could build their own proprietary N-tier architectures. The rest of the world had to wait for industry standards to bring down the price. As it turns out, Web application servers combining Java and other object-oriented programming technologies with various Web, Internet, and client/server technologies have become the open systems version of the plumbing required to support N-tier computing. With Web application servers and object-oriented programming tools, companies can distribute application logic to dozens of servers and hundreds of millions of clients in a way that makes the best technical as well as economic sense. The combination also promotes the best ideas of the Web, including universal programming standards (Java and HTML programming, TCP/IP networking, and HTTP Web serving) and universal access (using a standard Web browser), from a wide variety of clients that is not limited to Windows-based PCs. At the very heart of this new hybrid client/server-Web/Internet architecture lies the Web application server.

In the simplest terms, Web application servers augment the functions of normal HTTP Web servers, which were great at providing static HTML pages, so they can provide more complex services. For example, these servers can provide a single environment to access legacy data and applications that could be running on multiple and often incompatible platforms. Web application servers can also manage server-side Java applets (commonly called servlets), as well as object-oriented programs that adhere to other standards such as C++ for most servers and clients for Microsoft’s Component Object Model (COM) for Windows-based servers and clients.

Web application servers typically also include high-availability and load-balancing features to keep e-business applications working at peak efficiency. They are also the main tool that companies rely on to identify class-of-service distinctions among users. Companies use these servers to develop and run the programming that allows an e-business suite to know the difference between a tire kicker and an actual buyer, and the difference between a customer who pays a lot for services and one who has bought limited services.

Another chore increasingly given to Web application servers involves presenting a single development interface to programmers. This interface keeps programmers above all the gobbledygook of object communication and brokering protocols such as Distributed COM or Common Object Request Broker Architecture (CORBA)/Internet Inter-ORB Protocol (IIOP) so they can concentrate on creating application logic. Web application servers can also include transaction servers, e-commerce servers and online catalogs, proxy- or Web page-caching servers, and directory servers for distributed file management.

As new requirements become apparent as customers and computer vendors gain experience creating their e-businesses, more functions will be pulled under the Webapplication server umbrella. The middle ground that Web application servers hold in e-

business applications is where almost all the action in application development will occur in the next decade. The numbers bear this optimism out. Last year, the total Web application server market, according to various industry estimates, was about $150 million, and about half of that was split between Sun Microsystems, Netscape, and Bluestone Software. IBM, a relative newcomer to the Web application server market, estimates that the market will grow to $4 billion by 2002 and figures that it will get a large portion of the AS/400’s piece of the market.

Rather than trying to cover all the Web application servers available, this article focuses on the four primary Web application servers currently available for the AS/400: IBM’s WebSphere, BEA Systems’ WebLogic, Bluestone Software’s Sapphire/Web, and Novera Software’s jBusiness4. Each distinct product will appeal to different kinds of IT organizations. Variety is the spice of life, and companies might even end up using a mix of these and other Web application servers as they evolve their e-businesses. (To find out about other vendors that offer Web application servers, visit the MC Yellow Pages at www.midrangecomputing.com/yellowpages. Click on Internet/Intranet.)

IBM WebSphere

IBM’s (www.ibm.com) WebSphere Application Server currently comes in three flavors. The Standard Edition of WebSphere comes free in OS/400 V4R3 and V4R4, and it is the base product in the family. It includes IBM’s HTTP Server (formerly known as Domino Go and Internet Connection Server) as well as a plug-in program for that Web server that allows WebSphere to run and administer Java servlets. IBM includes this support for servlets in the hope that customers will use servlets instead of more cumbersome Common Gateway Interface (CGI) scripts to control Web pages and access to AS/400 databases. The Standard Edition also includes support for JavaServer Pages (JSP), a technology that mixes Java and HTML to create dynamic Web pages that is akin to Microsoft’s Active Server Pages (ASP) for its Internet Information Server (IIS) for Windows NT.

On NT, AIX, and Solaris platforms, WebSphere Standard Edition includes an IBM technology called Fast Response Cache Accelerator that substantially improves the throughput of Web servers; on the AS/400, similar caching software already built into OS/400 makes the technology unnecessary in WebSphere. The Standard Edition also supports the Secure Sockets Layer 3 data encryption protocol, which is commonly used to add security to e-business applications. In addition, WebSphere includes high-performance database connectors and application services for application session and state management.

IBM plans to add support for the open source Apache Web server to WebSphere. Apache already ships on NT and UNIX and is currently in beta on the AS/400. (Apache, slated to ship in late January through the Apache Project Web site, has not yet shipped as of this writing. IBM is mum on delivery dates.) IBM will probably add support for I/NET’s just-announced port of Netscape’s Enterprise Server to WebSphere sometime in the near future, too. WebSphere Standard Edition costs $795 on NT and UNIX servers and is free on S/390 mainframes running OS/390 and on AS/400s running V4R3 and higher.

WebSphere Advanced Edition has all the same features of the Standard Edition but also includes support for the Enterprise JavaBeans (EJB) framework for Java components. IBM says that the great majority of AS/400 customers do not, as yet, require EJB support and cites this as one reason it has held back the Advanced Edition of WebSphere on the AS/400 even as it is already shipping for Windows NT, AIX, and Solaris. IBM Rochester also comments that the EJB support is not yet robust enough to meet the stringent requirements of AS/400 shops, and the company doesn’t plan to release the advanced edition until later in 1999. (That will probably happen at the same time as IBM ships Universal Database support for OS/400 V4R4 in September.) When it ships, WebSphere Advanced Edition for the AS/400 will include support for CORBA, database transaction monitoring provided through IBM-developed EJB and CORBA components, the

NetObjects Fusion Web development tools (IBM is a majority shareholder in NetObjects), and the VisualAge for Java tool. WebSphere Advanced Edition costs $6,000 per server.

WebSphere Enterprise Edition, says IBM, really targets IBM S/390 and high-end RS/6000 shops that want to reimplement the program logic of their mainframe and UNIX applications while making use of familiar TXSeries transaction monitoring programs from IBM (namely the CICS and Encina monitors). This edition of WebSphere also includes IBM’s implementation of the CORBA object brokering standard, Component Broker, a predecessor to the evolving EJB standard that focuses primarily on C++ objects rather than on the Java objects controlled by the EJB portions of WebSphere. IBM will make this product available sometime in the second quarter of 1999.

In addition to these three editions of WebSphere, IBM also sells the WebSphere Performance Pack (WPP) for high-end Web sites and WebSphere Studio for Web page development. WPP is a set of caching and load-balancing programs that IBM developed for its Nagano Winter Olympics Web site and has made available for AIX and Solaris; it costs $7,500. Last year, IBM said that it would eventually port WPP to the AS/400 but now says that it probably won’t. It is really aimed at complex, high-volume Web sites or Internet service providers, not at midrange AS/400 customers with low-volume Web traffic, so not having it on the AS/400 is no big deal. The WebSphere Studio includes NetObjects Fusion, NetObjects ScriptBuilder, VisualAge for Java, a Web developer workbench, and servlet generation wizards for gaining access to databases through the Java Database Connectivity (JDBC) protocol and through JavaBeans. This development toolset runs on Windows 95/98 and Windows NT and costs $495.

As for the future, IBM plans to add WebSphere servers for OS/2 Novell NetWare and has felt some pressure from customers and Business Partners to support the product on the HP-UX and Linux variants of the UNIX operating system. IBM claims it will eventually bring its Net.Commerce e-commerce software as well as its SanFrancisco Java frameworks into the WebSphere fold and is even talking about the possibility of supporting Microsoft’s COM and ASP technologies.

BEA WebLogic Server

BEA Systems (www.weblogic.beasys.com), which sells the Tuxedo and Top End transaction monitoring programs for UNIX servers, bought privately held WebLogic for its Tengah Web application server just as that acquired company was porting Tengah to the AS/400. The port was pretty easy for WebLogic, now called the BEA WebXpress division, since Tengah, now called WebLogic Server, was written in 100% Pure Java, which OS/400 V4 supports. WebLogic Server is noteworthy as the first Web application server to fully support the EJB 1.0 specification.

Unlike many Web application server vendors, BEA is not trying to sell IT managers a complete, overarching framework and toolset for developing e-business applications. It doesn’t much care about RPG or C++ coding for applications, either, and has wholeheartedly joined in with the Java crowd. BEA bought WebLogic because it firmly believes, as does IBM, in Java as the language of the future. (Equally important in influencing the purchase is the fact that NetDynamics and Kiva, the two most popular Web application server vendors in the UNIX market, had already been taken over by Sun Microsystems and Netscape Communications, companies that, thus far, have not ported their products to the AS/400.)

Moreover, unlike many other vendors that write their own APIs or push their own development tools that make use of those APIs, BEA is sticking tightly to the open Java and related object standards. BEA is certain that the key to success in this market lies in supporting as many tools as possible, not in trying to push its own. BEA, like the employees it got by buying WebLogic, believes that adhering to standards is the only way to guarantee that any client will be able to access any server from anywhere, whether those clients are handheld computers accessing e-business applications through the Internet or suppliers and distributors coming in over a corporate extranet using full-blown PCs.

In late February, BEA reorganized its transaction processing middleware products and started mixing them with the WebLogic technologies it had acquired to create a new product line. AS/400 customers will probably be most interested in WebLogic Server, the Web application server that runs on AS/400s, as well as NT, Solaris, HP-UX, and AIX servers. WebLogic Server runs on Linux already but hasn’t been formally announced, and BEA is working on versions of the product for Tandem NonStop, Sequent NUMACenter, and IBM S/390 servers. Pricing for the WebLogic Server starts at $10,000 per processor.

BEA has announced a low-end JDBC server based on Tengah that generates Web pages from JDBC queries. Like IBM, the company has also announced a high-end product, WebLogic Enterprise, that combines the company’s Tuxedo M3 middleware with its WebLogic Server. While WebLogic Server supports Java and EJB, WebLogic Enterprise offers interoperability for EJB and CORBA objects.

Bluestone Software Sapphire/Web

If BEA’s WebLogic is a minimalist interpretation of what it means to be a Web application server, then Bluestone Software’s Sapphire/Web product suite is at the other end of the spectrum. Bluestone Software (www.bluestone.com) got its start as a UNIX consulting firm in 1989 and has transformed itself into a Web application tool developer. In 1995, Bluestone announced the Sapphire/Web application server, which has been available on the AS/400 since December and which also runs on S/390, Windows NT, and various UNIX and Linux servers. Bluestone believes that its integrated development environment coupled with its Web application server gives it an edge over competitors IBM and BEA Systems.

Sapphire/Web consists of five separate components. The Sapphire/Universal Business Server (UBS) provides Web access to host applications as well as load balancing, similar to WebSphere and WebLogic Enterprise. Programmers create applications for UBS using the Sapphire/Developer tool, which runs on UNIX or NT workstations and can create C, C++, or Java code. The Sapphire/Web suite also includes an Enterprise Developer Kit for creating distributed applications and an Application Manager for monitoring performance and status information of Web applications. In addition, a dozen integration modules can link Sapphire/Web applications to various third-party software suites (SAP and PeopleSoft modules are ready for AS/400 customers, and support for J.D. Edwards is on the way) and middleware products (IBM MQSeries, BEA Tuxedo, plus many others).

Many of Bluestone’s competitors don’t subscribe to Bluestone’s central tenets. The company believes that customers really want a single set of integrated tools that run on all major platforms and control everything that is in any way associated with its Web application server in an e-business application. The company isn’t foolish, however. Those using Sapphire/Web can also use other tools to create Java and C++ objects for use by the Web application server and its applications. (That means VisualAge for Java or ILE C++ for most AS/400 customers.) Similarly, Sapphire/Web integrates with all the major enterprise management frameworks from Tivoli, Computer Associates, BMC Software, and others even though it has lots of its own management features.

Bluestone doesn’t publish list prices for its Sapphire/Web suite. The company currently charges for its software based on the aggregate number of Web interactions customers push through Sapphire/Web during the course of a year, but soon it will also offer server-based pricing that more closely resembles its competitors’ charge structure.

Novera Software jBusiness

As this article go to press, Novera Software (www.novera.com) is just finishing up certification of its jBusiness object application server, a variant on the Web application server theme. jBusiness, which is in Version 4 right now, doesn’t incorporate a Web server but rather works with most of the popular Web servers on popular platforms and does many of the same jobs that a Web application server performs. Actually a sophisticated, high-level framework, Novera’s jBusiness allows customers with legacy

applications to analyze their databases, create jBusiness objects that mimic how applications access those databases, and then make those new jBusiness databases access objects available to developers who work with a myriad of Web tools to create new Web-enabled applications. (As far as Novera is concerned, IBM’s VisualAge for Java and WebSphere Studio are the preferred Web tools on the AS/400.) If you think this isn’t useful, think of how many applications or parts of applications are involved in merely viewing data from different angles.

Novera says that its jBusiness tool is useful not only for customers trying to bring legacy applications out to the Web but also for linking existing Web and intranet/extranet applications that have been developed on freestanding and usually incompatible platforms back into legacy applications. As with other Web application servers, jBusiness hides all the underlying, acronym-infested plumbing (LDAP, JDBC, SQL, EJB, etc.) necessary to create modern applications from programmers who just want to add program logic to their data. jBusiness also includes end-to-end management on both clients and servers running Java that actually lets IT managers see and tweak Java servlets and applets that are part of an e-business application suite as they are running. The jBusiness runtime environment costs $9,995 per processor, and the development environment, which runs on Windows 95/98, NT, AIX, HP-UX, and Solaris, costs $3,495 per seat.

Some Advice

In the past, when it came to application development, the best advice for AS/400 customers was to just do things IBM’s way. The advent of client/server technologies and, more recently, the various Internet and object-oriented technologies that are used to create e-business applications has put AS/400 programmers and managers in a position in which they now have to make choices—often tough choices with far-reaching effects. This is certainly the case with Web application servers. But remember, even if you pick the wrong Web application server after a lengthy search and trial period, much of the work you do for one Web application server is usable by another product because in most cases they adhere to open standards. So you don’t need to be too stressed about making a choice. The point is to get moving and start learning how to use these technologies and the products that support them to create e-business applications.