Wednesday, May 22, 2024

Bridge your legacy systems to the Web

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There’s something comforting about neighborhood hardware stores–something evocative of father-son projects on Sunday afternoons in autumn. Technically speaking, the thousands of Ace Hardware stores that dot the country are anything but refugees from Mayberry RFD. They’re actually sophisticated end users of local computing power, and they want to be able to use the Web to place orders with their supplier, Ace Hardware of Oakbrook, Ill.

This business of linking the Web to the rest of the enterprise has become central to the jobs of IS staff. The demand for access has sent them scurrying for middleware solutions to connect Web technology to relational databases, legacy systems, and the rest of the IT infrastructure.

Middleware by any other name

Middleware definitions get sticky when products that, at first glance, aren’t middleware provide middleware functions. Ostensibly, Amazon from Intelligent Environments in Burlington, Mass., is not middleware at all. Rather, it’s a “development environment for Web-based applications.”

But, if you’re going to develop for the Web, you’re going to have to link through something. Amazon has lots of links to databases, making it look a lot like middleware–and that’s how some users treat it.

Lereta Corp., a Covina, Calif., company that provides tax servicing for mortgage banks, used Amazon as a Web link. In many states, mortgage companies must keep track of the tax records of the properties they finance. In a fluid real estate market, where properties change in value at high speed, that can get “kind of complex,” says data communications analyst/Web master William Burnette. So the banks turn to companies like Lereta to do the job. The firm also provides flood zone determination. “We have what may be the nation’s largest database on flood zones,” says Burnette.

In the past, Lereta’s subscribers dialed into its mainframe system and extracted property and tax information via standard terminal emulation. Now they want to do so via their browsers–a delight to Lereta, since that removes the process from its mainframe and 800 phone line. “It’s going to take our maintenance cost down a bunch,” Burnette reports. “And we’re not going to be spending $50,000 a month on phone bills.”

Burnette set up an NT-based Web server, which links to the company’s mainframe via SNA. The rub was in connecting the Web to the database. The company’s ES 9000 mainframe runs VSE. “That’s important because MVS is relatively easy to link, but VSE is hard,” he says.

Lereta uses Software AG’s Adabas and intended to use that vendor’s middleware to link to the Web, but Burnette was concerned that it would tie Lereta to a product that was too proprietary. He therefore turned to Amazon, which provided the company with both a development environment and a way to link its application to the Web. “Basically, what we’re doing is using it as middleware to integrate all our existing databases on the mainframe with our other systems,” he says. “Amazon integrates everything in just one shot. It can talk to OLE, CICS, and the Web.”

Amazon isn’t the only product that’s kinda, sorta middleware. InterWorld Technology Ventures of New York City makes its money in the Web-based electronic commerce business. “We’re definitely at the high end of the market,” says president and chief technology officer Michael Donahue. “Our customers tend to be building major businesses around the Web.” InterWorld’s Oasis product suite includes electronic catalog, order entry, and back-end transaction processing technology.

“Oasis can also be used as a middleware application,” Donahue says. The suite includes an assortment of high-speed proprietary gateways to such RDBMSs as Sybase and Microsoft’s SQL server. It also has generic ODBC connectivity and, says Donahue, “as a last resort, it can use EDI” to get at legacy applications.

The bad news is that there are dozens, perhaps even hundreds, of middleware vendors vying for the role of universal Web-to-enterprise link provider. It’s a product and technology explosion on the scale of a minor Big Bang, and it’s every bit as chaotic and confusing as its cosmological cousin.

Middle of the road

Defining the technology is harder than you’d think. In general, middleware can be said to be the glue (or logic) that lies between the client and the server. Invisibly to the user, it deals with all the grim stuff of incompatible operating systems and file structures.

Middleware comes in five different types: database middleware, message-oriented middleware (MOM), object request brokers (ORBs), remote procedure calls (RPCs), and transaction-processing (TP) monitors. (For definitions of all of these, see the sidebar below, “Middleware methods.”)

However you classify it, middleware is important, says Chris Stevens, electronic commerce analyst at the Boston-based market research firm the Aberdeen Group. “The Web servers themselves–from Microsoft or Netscape or whoever–aren’t all that striking anymore. The key issue is providing the middleware necessary to bring corporate systems onto the Web.”

“Absolutely,” agrees Erica Rugullies, research analyst at the Hurwitz Group in Newton, Mass. “The companies, the users, are looking for integration with their back-end systems. And that’s not easy.”

The result has been a boom in the middleware market. Dozens of companies, ranging from start-ups to giants, have developed products that they hope will be to the Web market what Phoenix Technologies’ BIOS was to the PC market–that is, the invisible but universal common denominator that makes computing possible.

All five of the major middleware types are represented among current offerings. Particularly active are the database companies; all of the major RDBMS vendors, from Informix to Unify, are offering software to link their databases to the Web. Some are actually developing entire Web-based computing architectures for a computing model in which the de facto user interface is the browser; Oracle’s Network Computing Architecture and Informix’s Universal Web Architecture are examples.

However, many of the larger architectures are still under construction, and the pure database-to-Web middleware solutions don’t necessarily link Web sites to other legacy systems. So, at least for the moment, the focus of the Web-middleware market tends to be on the third parties that are following either a MOM or a combined ORB-TP monitor strategy.

Why these two? Chiefly, “because message-oriented middleware and ORBs came out of LAN and WAN markets,” says Tom Laffey, cofounder and vice president of engineering at Talarian. The other middlewares tended to come out of pure client/server applications, where one large system is connected to one smaller system. On the Internet, by contrast, a great many systems of any number of sizes are talking all the time. “And message-oriented middleware had already worked out the sorts of issues involved [in that kind of communication] long before the Internet came along,” he says.

MOM’s way

Ace Hardware used middleware to connect its Web server to its database, says IT project leader Robert Blair. All of the company’s product information, order entry facilities, billing systems, and so on are on an IBM mainframe. The Web server, by contrast, is on a Pentium server running Microsoft’s Internet Information Server. Somehow, the two had to link.

One problem was that some of Ace’s data is in flat files. “We have DB2, but we also have IMS databases,” Blair says. That means ODBC, the usual method of linking Microsoft’s Web server to other databases, wasn’t open to Ace.

Middleware directory

Middleware methods

Database middleware,usually a product of the database vendors themselves, provides only database connectivity. However, much software finds the same functionality in the Open Database Connectivity (ODBC) standard.

Message-oriented middleware (MOM) is based on message passing and message queuing.

ORB middleware makes use of an object request broker, software that manages the relationship between clients, servers, and objects.

Remote procedure call (RPC) middleware sends a call from one machine or process to another machine or process for some service.

Transaction-processing (TP) monitor middleware is a layer of management logic between clients to control transactions as they move from one place to another. It ensures that messages from one device or process arrive at another.

Fortunately for Ace, Precise/CPE from Precise Software Solutions, based in Braintree, Mass., and Tel Aviv, was designed for exactly this kind of problem. The message-oriented middleware product provides a single API on Web and legacy systems, so the API looks like Java to Java applications and like ActiveX to ActiveX applications. When the resulting application exchanges messages with IBM SNA systems, it speaks in APPC. A request for data or a transaction can come into a Web server running Precise/CPE as a standard HTML-style communication, where it is turned into APPC and sent winging off to a mainframe. Now Ace’s Web-using customers can access IMS data and have it come back to them as HTML files.

And Blair could do it all without spending decades writing code. “Using it is as easy as calling a subroutine,” he says.

There’s no shortage of MOMs on the market. IBM has been widely promoting its MQSeries as a MOM for the Web, and Digital Equipment has been saying the same about its DECmessageQ. Talarian offers SmartSockets MOM; Momentum Software says it has shipped over 100,000 copies of its X*=IPC. VCOM, originally developed by Swedish car maker Volvo, is now being actively marketed by Veri-Q. Even database vendor Sybase is introducing a MOM. A quick browse of the Message-Oriented Middleware Association‘s Web site shows many others and more coming.

Should you ORB it?

While MOM tends to show up in proprietary technologies, ORBs (thanks to the Object Management Group’s efforts) are neatly standardized around the OMG’s CORBA.

One potential threat to an ORB standard is that Microsoft and Digital support a non-CORBA ORB, DCOM. The possibility of two ORB standards has scared some users away from ORBs entirely. This is true even though Microsoft now seems to be backing away from DCOM as it revs up its marketing and development engine for the Microsoft Transaction Server, a.k.a. Viper, a TP middleware product that could give Microsoft ActiveX applications legacy connectivity.

Moreover, ORBs–by definition–are set up to deal with objects. This can be troublesome if you want to connect to non-object-oriented legacy systems. “The problem with most object-oriented solutions is that they expect objects at both ends of the pipe,” says Chet Geschickter, vice president of marketing at Precise Software. “And that’s not the case when you are trying to talk to legacy systems.”

Despite these problems and the attractions to MOM, ORBs seem to have won the war for the hearts and minds of the industry. They are perceived as one of the fundamental pieces of the emerging standard architecture of Web-based corporate computing.

“When you look at Netscape with its Netscape ONE architecture, or Oracle with its Network Architecture, you see competing implementations of a very similar architectural vision,” says Brian Croll, director of marketing for Sun’s Solaris servers.

In that architectural vision, he says, you have several standard components. “You have Java on the desktop, and then on the server side, you have servlettes [server-side Java code]. Then you have IIOP, and finally, WebNFS.”

Presumably, Microsoft would add ActiveX to the list along with Java. But it’s the Internet Inter-ORB Protocol (IIOP) that’s important. This is aCORBA-based protocol, promoted by the OMG, for communication between objects and applications, particularly on the Internet and within intranets.

IIOP suddenly became the de facto standard for object-related activities on the Web last July when Netscape announced that it would embrace the standard. It made IIOP part of its Netscape ONE architecture and licensed an IIOP-compliant ORB from Visigenic Software, the ORB-middleware vendor headed by Informix founder and database pioneer Roger Sippl.

The endorsement launched ORBs into intranet stardom. “It really gave the ORBs a shot in the arm,” says one developer who asked not to be named. “After the OMG spent years getting everyone to standardize on CORBA, it all seemed to lose steam. Then along came the Web and WORBs [Web ORBs], and everything’s back from the dead.”

WORB vendors are booming. “All the former ORB suppliers are in the market,” says Aberdeen’s Stevens. “Anyone who was building distributed applications is now on the Web…with CORBA as the resounding ORB of choice.” He cites in particular IONA Technologies, which has combined its Orbix ORB with Java to produce OrbixWeb.

Some ORB vendors are offering middleware packages that pair an ORB (not always CORBA-compliant) with another technology–usually a database. The result is a powerful middleware-development environment combination.

Late last year, OODBMS vendor GemStone Systems revealed that it was moving Webward. The Beaverton, Ore., company announced a CORBA-compliant ORB, GemOrb, along with products that give Web browsers and Java applications access to the GemStone OODBMS. Web applications talk to the GemStone DB, which in turn talks to legacy systems via GemOrb.

Computer Associates, which markets a proprietary ORB and TP monitor, also offers Jasmine, an OODBMS designed for multimedia and Web applications. A user can directly contact it via standard HTML or hook up through a Web server via a CGI gateway. Jasmine can then link to legacy systems via SQL. “This means that you can store new media, like video and graphics, in Jasmine, and still have access to older data in other databases,” says Yogesh Gupta, senior vice president of product strategy at CA. For instance, a company could combine a database of employees with photos by putting the graphics in Jasmine and leaving the tabular data where it is. When a user calls up a record, the browser sends a request for it to Jasmine, which extracts the relevant data from the RDBMS, combines it with the photo, and sends the whole to the browser for display.

One ORB-Jasmine user is Financial Technologies, a New York City software company that develops financial applications for the securities industry. “The securities industry needs a lot of information on demand,” says chairman and CEO Charles J. Lewis. “It often requires complex calculations and the integration of multiple bits of data. It is thus an appropriate use for objects.”

But he also has to have relational data. “Behind the scenes, we’ve got a very robust set of applications on RDBMSs–Oracle on Sun and DB2 on IBM–that gather data from both market sources and back-office processes, things like accounting.”

And then there’s the Web connection. The users are Wall Street brokers who might want to view data with their browsers. This led Lewis to Jasmine. “We started development about a year ago,” he says, “and we’re still in the development phase.”

Financial Technologies chose Jasmine because “we liked its pure object focus,” Lewis says. “Some products attempt to combine relational and object functionality in the same product. We think that both technologies have their place, and we like vendors who focus exclusively on what they’re really good at.”

The more the merrier

ORBs and MOM don’t have the field wholly to themselves. Other middlewares are aiming at your Web business, too. Gradient Technologies, for example, offers WebCrusader, a Web middleware based on the Open Software Foundation’s DCE network environment and Java. Several companies, such as Sanga International, are looking at the Java Database Connectivity (JDBC) standard to improve database connectivity to the Web.

Basically, it all comes down to timing. In the very long term, the various attempts to create complete Web-based architectures for computing might turn Web-to-enterprise links into system-level functions. In the short term, the Web-link business seems to belong pretty firmly to MOM and ORBs, simply because the market is behind them.

But what about the medium term? Will either MOM or ORBs emerge as the dominant Web middleware? Probably not. In fact, the whole point may become moot, with MOM and ORBs continuing to blend into something like the MORB. Says Talarian’s Laffey, “The ORB vendors are adding messaging to their ORBs, and we [MOM vendors] are adding bridges to ORBs. In two to three years, they’re going to come together.”


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