Industrial Strength VM Web Serving in Practice

I'd like to relate a real-life case study of VM used as a Web server at Merrill Lynch (The first part of this page is abstracted from an article I wrote for Gabriel Goldberg, that appeared in a publication of Sterling Software's VM division.)

Merrill Lynch has used TCP/IP under VM since 1987, and started using VM as a Web server on its internal TCP/IP network (our Intranet) in early 1995. Early in 1996, we placed our VM system on the Internet as part of our corporate Web site, where it provides market data to browsers from all over the world. VM is a flexible, economical Web server, providing value for our clients.

The value that VM brings to Web service is not just delivering HTML pages and graphics, though it does that well. Its real value is providing Web access to so-called legacy applications and data.

The VM system is probably the most frequently hit Web site in our private network, with the possible exception of the server containing the Web sites directory. This is because our VM system offers useful applications and business data: over 90% of VM Web hits are for CGI scripts, accessing applications like the phone directory, PROFS calendar, stock market quotes, mortgage and investment calculators, datacenter job tracking system, and various reports that were formerly printed, displayed on 3270 terminals, or downloaded to PCs. This is unique advantage and value provided by VM. We also serve information from MVS via shared DASD, files transmitted from MVS, and DB2 access.

The application that draws the most hits, and became the basis for our VM system's presence on the Internet, is a market data application providing stock quotes. This is a legacy application we've had for many years. Nonetheless, it was easy to write HTML and CGI scripts to make it available to Web clients. Within a few days, I finished an attractive Web application that lets anyone with a Web browser check stock prices as they change throughout the day. This application is unique among our Web sites: VM is our only system with real-time market data (actually, delayed 20 minutes for legal and licensing reasons) also hosting a Web server.

This application made VM a candidate for our Internet Web site, where we wanted to provide information content to visitors. The burden of proof placed on VM was demonstrating that it could do the job; it became clear that VM could act as a reliable, low-overhead Web site, with little incremental cost, interoperating without difficulty with other servers on our site, and serving widespread customers.

A VM advantage is high productivity of its programming environment for creating Web applications. CGI scripts written in REXX, based on CMS Pipelines, are far more effective for quickly generating solutions than C language code. Our experience with REXX and Pipes suggests that reasonably coded CGI programs exploiting features of the environment impose minimal CPU overhead and provide very competitive performance. Builtin functions of REXX, CMS, and especially CMS Pipelines make CGI scripting on VM an extremely effective method to deliver fast, flexible, efficient solutions. We also find that ease of use of VM, REXX, and Pipelines provides a very easy and fast learning curve for developers we are training for the VM Web site. It is far easier to train programmers on these tools than for Unix's Perl or C.

The time-to-market opportunities are especially impressive. In a meeting to decide the architecture of our evolving web services, a subject discussed was whether VM should be a socket-based server to a Web site composed of NT and UNIX machines, or continue as a Web server. A colleague -- who works exclusively on Windows NT -- offered the following unsolicited testimonial to VM when he told one of his employees

No, you don't understand -- I've seen Jeff's code and he has these great tools (he saw REXX and a PIPE with a LOOKUP and SPECS) that let him create results much much faster than we ever can with C. We can't afford not to use that since his platform is so flexible.

These developments demonstrate VM Web site advantages: it's a client-server system, yet it's also a robust, mature system with valuable applications. VM reliability and security also make it attractive, and low incremental cost for adding Web services make it a cost-effective way to provide Web functions and services.

I had a little epiphany one day while viewing Web log records from the Internet server, which displays information including browser type. Imagine my surprise and delight at seeing a Charlotte client on CMS talking to a VM server! There is ample evidence that VM can be a highly effective, competitive solution for many institutions' Internet needs.

Further developments

Our Internet web site is partially on NT and partially on VM, using an expanded version of the market data web application. If you look at http://www.ml.com (depicted below), the Java ticker at the top, Market Quotes, Feedback, and the ML 100 Tech graphic all run on VM. In other words, VM is on the home page of the world's largest brokerage. (Click on Market Data, and do a View Source on the center frame for verification...)

Furthermore, all the web site feedback pages and responses are VM web pages using CGI scripts based on the one written by Harry Williams at Marist.

Our incremental costs were negligible, and we have had little difficulty providing a high level of service. We had over 18 million VM web hits in 1997, counting both intranet and Internet services, exceeded 70 million hits in 1998, and passed 100 million hits for 1999 in fall.

More people in my company are exposed to a VM application than ever before

We're delivering FOCUS applications from VM web servers, and DRDA access to DB2 databases running on MVS. I wrote a mail review system that captures email between our brokers and the public, that will allow supervisors to review the email sent by the brokers, using the web as an interface to data stored on VM. VM was selected because we knew it would scale, was reliable and secure, and could deliver the function quickly.

We're hardly alone in this type of highly successful effort. Vincent Casale at Lehman Brothers rolled out a production VM web application providing a modern face for CICS applications, using APPC verbs in his REXX CGI scripts to communicate with CICS COBOL. This demonstrates VM's unique capabilities: efficient delivery of web access to native mainframe applications.

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