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Everyone's talking about linking intranet and extranet applications to legacy systems. Here's how you really do it.
By Peggy Watt When two Massachusetts hospitals joined forces last spring to become UMass Memorial Health Care, the newly combined IT staff faced the usual challenge of merging disparate networks. But the World Wide Web added a new twist: A large corps of doctors was demanding remote browser access to records. UMass Memorial, meeting the demand, is rolling out browser-equipped PCs by the hundreds. But typical of hospitals, the institution also is busily operating legacy applications. The mainstay applications run on a variety of computers, including AS/400 servers, mainframes and AIX workstations, says Bob Brandner, executive director of network computing at the Worcester, Mass., medical facility. Pair this PC explosion and Web enthusiasm with Year 2000 concerns and aging COBOL code. Is it time for UMass Memorial to unplug the mainframe in favor of a Web server? Don't you believe it. Rather, as Bogart put it, this could be the start of a beautiful friendship. Building a bridge between the company Web and legacy systems is a natural. But structural details are still being worked out at companies across the country. At UMass Memorial, IT turned to Wall Data's Cyberprise suite as a means of connecting the Web and host resources. The team was familiar with Wall Data of Kirkland, Wash., because one of the hospitals had been using Rumba, the vendor's traditional terminal-emulation software, for three years. The migration to Wall Data's Cyberprise Web-to-host connectivity suite didn't quite require an overhaul, but it was time-consuming, Brandner says. The IT team had to build an intranet that uses a Cyberprise Web server to link into the hosts. Local users log on to the intranet to get at legacy data. Remote users - mostly doctors - surf in and download Cyberprise objects, which are actually Microsoft ActiveX code. A virtual private network and the Secure Sockets Layer (SSL) browsers secure the legacy access, Brandner says. UMass Memorial began testing the Cyberprise intranet in March with 100 physicians. It adds about 500 users each month; eventually more than 3,000 will be online.
No contestIntegration projects such as the one at UMass Memorial are becoming more common. In fact, the market for software that links legacy data and corporate Webs will grow from $24 million in 1997 to $1 billion by 2001, according to market research firm International Data Corp. (IDC) in Framingham, Mass. Meanwhile, IBM says it sells more than 50,000 AS/400s yearly. It estimates 500,000 AS/400s are running in mid-size to large corporations, and, almost by definition, the machines run critical corporate data. If the IDC and IBM numbers show anything, it's that intranet and extranet technology and legacy systems need to get along. "The chief information officers of over 2,000 global enterprises are not about to throw out over $1 trillion worth of mainframe and other host applications," says Martin Marshall, an industry analyst with Zona Research in Redwood City, Calif. Host access traditionally refers to mainframes, but the term really applies to clients talking to any legacy data or applications, be they on the Big Iron or a mid-range system. The term refers to transactions that are usually handled through tn5250 or tn3270 sessions to S/390 or AS/400 hosts, respectively, but it also covers high-end Unix systems. You can get at legacy data through traditional telnet and use green-screen commands, or you can bring the data and, with a little more care, the applications into the graphical desktop world. In fact, about 60 IT managers recently surveyed at Network World seminars said their companies have integrated or will soon integrate intranets with mainframes or mid-range systems. The top goals are browser access to IBM's SNA, terminal emulation with a Web interface and the use of Sun's Java or Microsoft's ActiveX in Web-to-host operations. But don't let mere popularity convince you to build a bridge between your mainframe and the Web. There are plenty of good reasons. Let's start with your public persona. Say you run the Web site for a health insurance company. The site is your public face, a resource for current and prospective customers. Those who surf the site might want to find out if their doctor is on your preferred provider list; that data is stored in your mainframe-based catalog. Need some Web-to- legacy integration, perhaps? Now move in another layer. A traveling sales representative or a business partner wants to check on the status of an order; that's in the procurement system, another legacy application. The user needs a password to become more intimate with corporate data. It gets even cozier inside the corporate walls. Suppose the human resources department in a fit of efficiency wants to provide electronic versions of its library of roughly a zillion personnel forms. All of that information is on an AS/400, but of course it is manually entered after employees fill out paper forms. There must be a better way. And here's another twist: Different parts of that personnel information are stored in a handful of legacy databases. You don't really want a half-dozen green screens on your monitor, connected variously to a couple of HR databases, the accounting department, corporate operations and who knows what else. Web-to-host software basically fools the legacy system into thinking it's communicating with its usual tn5250 or tn3270 session. It just sends down the chute whatever data the user requests; the Web client can display it in whatever fields or cells the designer maps out. An intelligent system can combine several retrievals into a single presentation. You probably won't tackle all this at once. In fact, most host access vendors encourage evolution - probably because they're still adapting their products to take advantage of this new spin. Wall Data, for example, maps out a guide that shows companies how they can dabble with entry-level query operations and publish legacy applications unmodified, but expand over time to accommodate new Web enterprise applications. And IBM, for example, offers a range of products for Web access to its mainframe, and a good selection of companies offer Web-to-host tools. Usually, pricing is based on the number of concurrent users. This technology doesn't come shrink-wrapped.
The basicsA Web-to-legacy operation relies on a host access server that supplies and manages the gateway between the host protocol, which is frequently SNA, and HTTP on top of IP, the Web's native lingo. The host access server can run on the host or the client. Here are the several ways to Webify. In the beginning, there was the terminal emulator. This client-side emulation technique basically puts a dumb terminal (tn5250 or tn3270) window on your much more intelligent PC. This is history, but many veteran vendors now sell browser versions of their terminal-emulation software. The emulation application might even run as a client plug-in - but it's still a green screen, and you can do better than that. The screen-scraper is a more intelligent terminal emulator and can show legacy data graphically. You call up a Web page and click on the Sales Figures link, for example. The Web server runs a script - be it a Common Gateway Interface script, or a Microsoft or Netscape API - that acts as the host access server. The host releases its raw sales figures to the host access server, which strips off some of the mainframe tags and translates the datastream to HTML. Sales charts pop up on your browser. Neither of these approaches supports real-time interaction between client and host. They're best suited for well-defined, static data access, such as that associated with phone book or catalog look-ups. Examples of tools enabling these capabilities include Attachmate's Emissary Host Publishing System and Teubner & Associates' Corridor. A more sophisticated approach takes the extra step of downloading a Java applet, ActiveX object or JavaScript from a Web server. The component program runs underneath the browser and manages the host datastream, retrieving and translating the text data to HTML. The host still thinks it's communicating with a terminal-emulation program. Client/Server Technology's Jacada and Simware's Salvo use this method, as does Cyberprise. Most of the Web-to-host products that perform translation or modified terminal emulation support Java and ActiveX. The advantage of downloading an applet or object is flexibility, as well as session orientation. That is, an applet can deal directly with the host (remember, it's playing host access server) and interact whenever data changes. But you'd better be running a browser that supports Java or ActiveX. Install with care on extranets - you don't always know what browsers users have. As a variation, the Java applet or ActiveX object may communicate with a terminal-emulation server. Also known as a terminal handler, it is an intermediary that talks with the host and may sit anywhere on the network. OpenConnect's OC://WebConnect takes this tack; its advantage is maintaining a central point for security measures. OC://WebConnect also encrypts the datastream between the terminal emulator and the client for greater security. Although the host access server can sit on the client, you might prefer one that runs on a network server. IBM's WebSphere plays multiple roles as Web server and host access server, and handles a number of other mid-range system communications tasks. If you spare the desktop the heavy lifting, even a thin client such as a network computer can easily handle legacy data. "We used to call this three-tiered client/server," says Jean Bozman, an analyst with IDC in Mountain View, Calif. "There's a client layer, an apps layer - in this case an Internet-enabled application - and then the back end is a mainframe or AS/400." Or the back end can be even bigger. One lure of browser host access is the ability to grab data from several legacy sources and deliver it on one Web page. That's the many-tentacled approach of PacifiCare Health Systems, a Santa Ana, Calif., health care provider that is building a Web interface to legacy data. Most of the data is in Oracle Rdb, but some is in several SQL databases. PacifiCare's member services staff will pluck information from a cross section of databases. The development team wrote SQL calls to Open Database Connectivity (ODBC) drivers that query the Oracle database and designed SQL look-up commands to other databases, says Cherie Ciotti-Roco, intranet project lead at PacifiCare. Microsoft Internet Explorer browsers replace the series of green screens. Oracle, which released a Web version of its Developer 2000 tools and updated its Oracle Application Server after PacifiCare began its project, advocates keeping the host access server on a central machine. Then the host access server can act as an integration platform and can grab data from many sources, says John Fomook, product marketing director for Oracle's application server division. "The server gives you a platform on which to build terminal access, encapsulation of legacy applications or other processes that you will add over time," Fomook says. Net managers can add databases through gateways or by writing ODBC drivers. Another Oracle user, Book-of-the-Month Club, wrote scripts in Oracle's PL/SQL to browser-enable the database, opening the door to features not possible with the company's custom client/server application. Browser users could save reports in different file types and grab data easily even from a thin client, says Brad Reisner, director of technology operations with the New York company, a division of Time Warner. It all worked so well that Book-of-the-Month Club launched electronic commerce on the Internet with several host connections, including one to an IBM mainframe and AIX data warehouse. Book-of-the-Month Club is composed of a dozen special interest clubs, each of which has 17 mailings per year - and now many club members can log on to place or cancel orders, Reisner says. The data isn't live; the Oracle Application Server that operates as the host access server also stores the data, which is periodically refreshed. Book-of-the-Month Club uses a Netscape Web server running on a Sun Solaris platform. "We needed to make sure we had good access to our inventory system for this to work, but it should cut down on returned shipments," Reisner says. The Book-of-the-Month Club site held up under more than a million hits in its first month.
No pain, no gainBy the very nature of the legacy beast, you'll have to pair some technologies that weren't designed with each other in mind. The good news is the selection of tools is growing and comes from many familiar sources. That means you don't have to duck the Web wave like you did the client/server one, says Daryl Plummer, research director for applications development management tools and technology at Gartner Group in Atlanta. He notes that Web tool makers have needed to produce robust client interfaces to the legacy environment, providing migration with as little pain as possible. That was The Santa Cruz Operation's (SCO) goal with Tarantella, which operates as a host access server and looks like any standard client to the host application. Tarantella can mimic an emulation terminal, an SQL database client, a Windows NT application or whatever you need. Tarantella translates the host data and serves a Java applet to the client, so a Java browser is a must. "If you have apps that you've taken years and years to develop, the last thing you want to do is change them. Our philosophy is don't touch," says Helen Goddard, director of Tarantella product marketing at SCO in Santa Cruz, Calif. SCO keeps its word, says Michael Prince, CIO of Burlington Coat Factory Warehouse in Burlington, N.J. Burlington Coat Factory, which is running a 100-user pilot program with Tarantella, serves legacy order entry and inventory data as HTML pages. The Web sites also sport windows running graphical reports from Oracle Forms, which sits on a Unix server. Prince says he runs most of the applications and other Unix server programs simultaneously and nearly constantly. "It all holds up pretty well," he adds. And there's always an overachiever in the crowd. This time, crown Advanta Business Services. The firm is a leasing systems provider that Webified, then enhanced, its core legacy application, implemented electronic data interchange and launched an extranet as its foray into Web-to-host projects. Advanta Business Services, a Voorhees, N.J., company that is a development arm of financial services firm Advanta, recently launched the ACESystem extranet to take online applications from vendors and brokers. The process started when a business partner asked Advanta to support EDI over the Web. "We decided to plunge in," says Jim Krzeszowski, Advanta's senior manager of software development, explaining that the company gets more business the faster it handles applications. Typically, staffers take applications by phone or key in written applications. So his team Web-enabled a leasing origination system the firm has used internally for years. The application is written with Forté Software's distributed development environment and interfaces with a Sybase SQL server database on an RS/6000 legacy system. Forté acts as the host access server, passing messages to the legacy system and returning HTML data to the browsers with help from some JavaScript code. ACESystem improves on the internal system by automating some responses. JavaScript routines check key fields and generate answers to common entries. Site access is password-protected and data is encrypted. "It was simple because we had the in-house legacy system already," says Krzeszowski, who admits his team had little Web and no Java experience.
Make a checklistSo you think you want to Webify your mainframe? If you can answer these questions, you just might be ready to tackle a Web-to-host project.
If it's OK for the data to be static, or at least not interactive, a screen-scraper might do the job. But if the application is better provided by drawing data from multiple sources, this might be the time to get your telephone order-takers off the green screens they must page through when accepting sales for different departments or catalogs. Instead, give them a single graphical form that feeds the information to various back-end databases as needed. Do you need to simplify what the host is sending? Try intelligent screen-scraping to rid clients of all extraneous stuff. The lion's share of Web-to-host applications is business-to-business electronic commerce, several vendors say. Screen-scraping is also an application that quickly brings positive feedback. Is that a 3270 terminal on a few hundred desks? If so, you're going to be shelling out for much more than a legacy integration application; you need to install Web browsers on something. It may be high time, but this also may be your cue to consider thin clients. And if you do have browsers, are they installed in anything resembling a standard, or are your desktops a potpourri of versions and varieties? Just how big is your budget for this?
Where will you apply the safeguards? Check one or more: at the LAN operating system logon; at the home page logon; at a subsequent Web page; at the legacy access system logon; at the database logon. Any legacy application fronted by a Web server can take advantage of that software's security technology, including password protection, certification, SSL and authentication. Satisfied yet? David Summer, senior planning engineer with Blue Cross of California in Woodland Hills, pushed the security point when the company decided to give customers access to some legacy data, protected by password and certificate. The Web-oriented applications team was not as security-conscious as he, an old mainframe guy, Summer says.
This is another sticking point for Web servers. Some say it's a matter of the server operating system (and Windows NT would be a usual suspect, to Microsoft's chagrin). It's Summer's other major concern. "As we expand the number of clients we service, we need to worry about scalability," he says. A corollary to the scalability need is load balancing. Summer is considering outsourcing the company's Web server hosting to a well-equipped shop with lots of server power to deal with load balancing. Do you want to get down and dirty with Java and HTML? How long do you expect to use that legacy application? Is it due for an overhaul? It's not just a matter of learning Java; you have to program the logic of your legacy system. Contrast the expected lifetime of the legacy application with the hassle of the programming project - maybe you should overhaul the legacy application first! (There's a reason that many Web-to-host tool vendors emphasize services along with their products.)
This is a stumbling block for Web-fronted legacy applications. Many legacy apps expect to have a sequence of transactions with a user, but Web servers and clients are built to retrieve one document at a time - and in no particular order. Web-to-legacy tools tackle this from several angles. Every transaction can stand alone, which works best with read-only operations. Or there are ways to build a script into the datastream through the terminal emulator and track the sequence of exchanges that mimic a host session. Do you really need to mess with this?
"You want to be able to pick whatever back end you want - an object database, SAP, Oracle or whatever - and be able to deliver to any front end, whether it's WebTV or any browser," says John Capobianco, senior vice president of marketing for Bluestone Software in Mt. Laurel, N.J. And an application server should support whatever enterprise modules you want, such as SAP applications or JavaBeans, Capobianco says.
"Capacity and performance are the most important features of any application," says an IT manager for a major public utility. "Web-to-legacy links can't be a pain to implement and keep up, and we can't just keep buying servers to speed response times," he says. Advanta's Krzeszowski rattles off his priorities without hesitation: performance, security, scalability and reliability. The number of users matters less than the strain on the application, he says.
Pick your methods based largely on your priorities. Don't forget to take inventory of browsers. And call on some of the vendors eager to help the IT department link its old and new environments - although the vendors draw from experience in related fields, when it comes to the Web, they're not long off the drawing board, either. They could use your input, too.
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Forum: Cutting through the hype
Contact Senior Editor Peggy Watt
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