Whipping up one big Web server

By Michael Cooney
Network World Fusion, 10/14/98

The more things change, the more they stay the same.

Certainly you could say that of the mainframe's burgeoning role as a monster Web server. Many industry watchers thought the big iron would have a little or no part in the exploding Internet world. After all, who would want to turn a stuffy old mainframe into a gleaming Web server? As it turns out, plenty of people do.

A recent study by International Technology Group (ITG), a consulting firm in Mountain View, Calif., shows that more than 2,300 organizations will be using a mainframe as a Web server by year-end. The study also revealed that some 10,000 organizations plan to use mainframes as Web servers by 2000.

IBM is making it easy. For example, the company has integrated a Web application server called WebSphere into the new version of its mainframe operating system - OS/390 Version 2, Release 6. WebSphere is an enhanced version of Lotus' Domino Go Web server. OS/ 390, which already included an HTTP server, now also offers a Java engine that can handle secure and nonsecure Web requests.

Third-party software

A whole industry of third-party mainframe Web server software has grown up in the past couple years. Packages such as Beyond Software's EnterpriseWeb, Domino Web Server and Sterling Software's VM:Webgateway all reside on the mainframe and make it a Web server.

Beyond's EnterpriseWeb is a Web server that runs under the VM or MVS mainframe operating systems. It supports HTTP and functions similarly to Web servers that run under Unix operating systems, the company says.

Providing graphical Web browser access to legacy SNA applications is the function of software such as Attachmate's Host View Server, Computer Associates' Opal, Wall Data's Cyberprise Host and WRQ's EnterView. These programs work by sending HTML versions of 3270 screens to a browser. Some programs also can download a Java applet to the user, providing Web access to mainframe applications.

"The large-scale transaction processing systems that will play a central role in electronic commerce in the future will be predominantly based on mainframe-anchored Web sites," says Bob Simko, ITG executive director.

Cost will be one of the biggest reasons, Simko says. The price of mainframe hardware, software and systems administration is some 25% less than related costs for comparable Unix and NT servers. Part of the reason for the disparity is the fact that a midsize to large mainframe can support between 23,000 and 100,000 users. Most good-sized servers individually can't come anywhere near supporting that many users, meaning multiple servers and copies of software would be needed to accomplish what a single mainframe could.

Still, it's hard for most observers to say for certain whether any users would go out and replace a Windows NT Web server with a mainframe. And even IBM doesn't seem sure that improvements such as integrating Web server software and security in the mainframe's operating system will drive the sale of big iron hardware.

"Clearly there is a call to integrate multiple servers, and the mainframe does that. We expect we will attract some customers who were not S/390 [mainframe] users before. But it's really what they need out of their Web server that will dictate how big or small a box they need," says Rob Vrablik, manager of e-business strategy for IBM's S/390 group.

There is a big business cost-justification for keeping the mainframe in the Web development loop: Most corporate mission-critical applications still reside on the mainframe and moving them off would be a sizable, complex undertaking.

The economics of recreating big applications and databases, which already reside on the mainframe, into less scalable and generally more unstable systems is a waste of money for most companies, Simko says. "Deploying the mainframe as a Web server is a natural extension of the S/390, since most companies' data and applications reside there anyway," Vrablik adds. "For most users, the capacity for rapid application development already exists at the mainframe, and it's not that hard to Web-enable existing applications."

That's the case with Merrill Lynch & Co. The New York financial firm decided to run its new stock market Web site, from which users can access everything from stock quotes to trade portfolios, on an existing Amdahl mainframe running the IBM VM mainframe operating system and Beyond's EnterpriseWeb. Deployment costs were in the $50,000 range and implementation issues were minimal because developers had extensive mainframe software experience, company officials say.

For other users, it's not really a question of why make the mainframe a Web server, but why not. Case in point: Incyte Pharmaceuticals in Palo Alto, Calif. The firm has a big Oracle database residing on a mainframe; all employees access the database via the World Wide Web.

"It's not really a traditional Web server but all of our new applications are developed there and all of our employees use browsers to get at the mainframe data," says Philip Kwan, manager of network operations and planning at Incyte.

The company chose to deploy a mainframe in this capacity for a variety of reasons, but the big iron's capacity to act on multiple workloads simultaneously and its security features were two of most important motivations, Kwan says. The company handles a lot of sensitive research data from multiple drug development companies so security has to be tight, Kwan says.

Security and workload capacity are the reasons most often cited for choosing a mainframe to act as a Web server. "It's hard to imagine another server that has the security, performance and accessibility of the mainframe," Vrablik says.

"As for security," he adds, "hackers can't slip an S/390 a 'Mickey' - the operating system and its security, cryptography and other protection has a 'shoot first and ask questions later' mentality that really prevents the mainframe from being invaded by a virus or unscrupulous person."

Indeed, IBM has, over the past couple years, beefed up the mainframe to make it more attractive as a Web server. OS/390 comes with an integrated firewall, a cryptographic coprocessor and support for a variety of security technologies such as Secure Electronic Transactions (SET), which helps ensure the privacy and integrity of electronic transactions.

IBM and competitors such as Cisco (via its mainframe-based IOS/390) have greatly improved the TCP/IP stack performance in the mainframe's operating system. And nearly all mainframe operating systems, including OS/390 and compatible software from Hitachi Data Systems and Amdahl, support Unix interfaces.

Whole lotta rosy

Of course, there are no free lunches, and making the mainframe a Web server in the heart of a big organization can be a tricky proposition. For one thing, while a mainframe does not often crash like PC or Unix servers do, what happens if you have a Web server problem that brings down the big box? Most companies go out of their way to avoid single points of failure. A mainframe failure could cause a companywide problem.

There also could be trepidation from IS folks who would be loathe to Web-enable a mainframe application that has been chugging along just fine for the past 12 years. Web-enabling legacy applications can eliminate or at least degrade some functions such as printing and application performance, experts say. It is also likely that users would need to upgrade mainframe storage facilities to handle the vast amounts of data Web applications and activities can use.

"Still, for organizations that already have mainframes," Simko says, "Web-enabling them will be faster, less expensive and easier than going out and investing in new Unix or NT servers."