Shops sample C/S OLTP, but keep bread-and-butter apps under wraps - early users of client/server transaction processing monitors usually start with noncritical systems

Software Magazine, Dec, 1994 by Brian Riggs

To monitor or not to monitor? Early movers of transaction processing applications to distributed, client/server environments test TP monitors, but primarily for noncritical systems. For "TP-lite", shops, DBMS toolsets may suffice.

Transaction processing (TP) monitors, long the high-end toys of mainframe-dependent MIS departments, are branching out these days. That's because organizations want to move some of their online transaction processing applications to open, distributed environments.

Credit at least some of this migration to database vendors who have been developing low-end tools that can serve as transaction processing surrogates. However, "databases do not scale well over large enterprises," said Alfred Spector, president and chief executive officer of Pittsburgh-based Transarc Corp.

With the Encina TP monitor, explained Spector, "we provide a virtual mainframe [for customers]." Transarc, recently acquired by IBM, offers Encina on Windows, Unix and NT systems.

According to Spector, Encina customers are typically large corporations that do their own programming. "We are not going to get a corner grocery store [as a customer]. But we might get a grocery store chain," he said.

Until recently, though, the large corporations comprising the bulk of online transaction processing (OLTP) customers have been loathe to move their bread-and-butter TP applications into a distributed environment. Reasons for hesitation include the significant financial and time investments associated with writing and maintaining transaction processing applications in a client/server environment, a general suspicion of Unix and the ability of open systems to handle important transactions.

Despite those misgivings, suppliers like IBM; Novell Inc., Provo, Utah; AT&T Global Information Solutions, Dayton, Ohio; and others are luring the mainframe dependent to TP monitors that run on Unix, NetWare, NT and OS/2. While slow to respond, organizations are beginning to move some of their TP applications to client/server environments.

"This is the next frontier for client/server," said Kevin O'Neill, vice president of research and consulting at the Business Research Group (BRG), a consultancy headquartered in Newton, Mass. At this stage of the game, though, "OLTP is in the evaluation mode and early pilot stages of development, so it will still take a few years to shake itself out," he said.

Mainframe Ties

While some Unix users are interested in developing TP applications for distributed computing environments from scratch, they are in the minority. Observers say the majority of users interested in TP as a client/server system are those who have benefited from the technology in the mainframe world and now want to rehost legacy applications.

The largest installed base of current TP monitor users have technology based on IBM's CICS, according to Michael Bigbee, director of business development at Dallas-based VISystems Inc. For this reason, in these glory days of MIS rightsizing, VISystems has developed the VIS/TP Transaction Processing System, a Unix OLTP product set that supports the CICS application programming interface (API). By connecting to the mainframe, Bigbee said, "we leverage companies' existing investments in mainframe applications like CICS."

Among the corporations taking this approach is stock brokerage Charles Schwab & Co. Using CICS as a TP monitor across an IBM SNA network, engineers at Charles Schwab's San Francisco headquarters are building prototype equity trading applications in preparation for distributing transaction processing over client-server networks.

According to Ron Welf, manager of performance and capacity planning, the company is entering the distributed OLTP market warily. "When you talk about mission-critical transaction processing, you are talking about pretty serious stuff. For our company it is the thing that pays many of the bills. If we are not doing online quoting and trading, our revenues are affected," he explained.

Schwab is in the process of migrating to a Unix-based network comprising more than 100 servers and several thousand end nodes, including workstations, X-terminals and Windows PCs in 200 branches throughout the United States. Using Paramount/XP, an enterprise resource management product from Herndon, Va.-based Legent Corp., the firm is "at the moment populating [the network] with applications that are not so much transaction processing applications as they are query systems. Over time we will be moving other applications [including OLTP! out there as well," Welf explained.

Among the benefits of putting OLTP applications into a distributed environment, said Welf, is that it reduces the chances of system-wide outages, because processing is handled across multiple platforms and geographic locations. However, there are drawbacks. "To manage that you will pay the price of having to figure out how to integrate the measurement data," warned Welf. And IS, he said, will not be able to locate data with the ease they did when everything was on the mainframe. "IS will have to go off to a different place when you don't have the data in a local file."