Past Issues of Government Technology

Legacy-data Strategies

"In with the new" doesn't have to mean "out with the old."

by / February 28, 1999 0
Thousands or millions of pages of information exist in state and local databases, safely tucked away in back-end "big iron" systems. This information could or should be made available to citizens, businesses or other agencies. The problem is how to make the transition from legacy to client server and Web-based applications.

One of the primary obstacles to moving such data around is at the network level -- the ability of older, mainframe-centric network protocols to talk Ethernet, the lingua franca of the new Web world. And while the network level is important, it should come as no surprise that there are also other barriers to hurdle. Moving data around requires work at all levels, from network to application. There is no simple, one-shot button that makes legacy data available everywhere.

The good news is that the industry is moving in the direction of interoperability. Vendors have begun to offer hardware and software to help agencies translate information from old to newer formats. This kind of support is particularly important when dealing with lower levels, such as the networking protocols. In the mainframe world, IBM's Systems Network Architecture (SNA) ruled for years, and still does to a large extent, as the standard networking architecture. While TCP/IP was built to be flexible and ignore or work around network problems -- important in a network protocol designed to function even if sections of the network were bombed out during an attack -- the original SNA controlled the entire network. Client sessions, routing decisions and network maintenance were controlled from the data center.

To achieve this high level of control, SNA required a high level of technical expertise. Maintaining an SNA network required a pool of technicians always available to install or maintain additions to the network, including such simple items as new workstations. Because IBM ruled the back-end big iron, it often ran on the LAN in the form of IBM's Token Ring network protocol.

While such control can be beneficial in commercial environments or when security is important, it is not helpful or even possible in wild, free-wheeling environments such as the Internet. Fortunately, solutions have begun to appear to help MIS departments rather easily translate from
the SNA and Token Ring worlds to Ethernet and back again. While this can make a big difference when trying to decide what to do with legacy data, it is really just the beginning of the story.

In fact, MIS departments have two general choices of how to approach the problem of different networking protocols -- translate between the two to allow easy exchange of data, or standardize one protocol and homogenize heterogeneous environments. Both approaches have their place.

'Webifying' the Legacy Back End

Most critical data for Marietta, Ga., resides on a legacy back end. But Gene Estensen, director of the city's MIS department, wanted to begin to make the data available via the Web.

"We wanted to put up a professional, good-looking site," Estensen said. "The end game for us is payment of bills -- utility bills or traffic tickets. [But to begin, we] just want people to be able to look at their payment history in graphical format."

The Web site Estensen is building will also accommodate strictly Web-based data. It will let departments enter and update the data they own. The personnel department can update the open jobs, the city clerk can update the minutes or the agenda for the City Council. Data such as the city's annual report and the city code will also be available. Still, Estensen's primary goal is to make legacy data available.

To get there, Estensen needed to build an infrastructure that would allow information to move between the mainframe back end and the Web front end, which runs on an IBM/Lotus Domino server. Most of his data was in IBM's DB2 mainframeclass database-management system and housed in a network system that speaks Token Ring instead of the Ethernet spoken by the desktops. Rather than converting the data or reworking the back-end network, Estensen went in search of a network-level product that could convert Token Ring to Ethernet. He selected a Cabletron switch because of its modular, scalable components, its available suite of options and its solid network management. He set up a fiber link from the back end to the switch to ensure solid back-end performance.

"My background is networking," Estensen said. "I knew what I wanted to do and was intent on using the same manufacturer throughout. We bought considerable equipment -- the same kind of equipment over and over. Once we learned it, we had it."

As of late 1998, the connectivity to the back end was in place, and the LAN was built -- Estensen had 10MB or 100MB Ethernet at every desktop.

This left the task of connecting the two. The back end was successfully passing the information, so the next step was to get the Domino developer to receive the data and display it. Estensen hoped to have the production system in operation near the beginning of this month.

Soon after, Estensen plans to focus on online commerce, since Marietta is in the electric-power business already and, with deregulation of the gas industry, plans to get into natural gas as well.

Keeping the existing data on a legacy back end and simply translating the protocol at the switch allowed Estensen to avoid the hassles of data and network migration. Estensen highlighted one factor as being key to the success he's had to date: "I've been here less than three years. The first thing I did was stop everything and built a good network. Otherwise you're building a house of cards. We have the Internet to every desktop and a robust network."

From the Ground Up

Ira Brand, the enterprise network engineering manager for Georgia's Department of Human Resources, is responsible for a 41-story building that was three-quarters Token Ring and one-quarter Ethernet. As part of a larger effort to standardize all equipment and software, Brand decided to convert entirely to Ethernet. Fortunately, most of the existing equipment was at or near the end
of its serviceable life and so was due for replacement. Brand got rid of the Token Ring hubs and replaced them with Cabletron Smart Switches.

"We were trying to make life easier for our support, by having one vendor [for each type of product] -- the same Ethernet cards in all computers, the same switch on all the floors," Brand said. "We have some systems [still] using Token Ring, but they will be switched over to Ethernet. To get to the mainframe SAA gateways, we put a card in the Cisco router."

The department's effort to standardize has gone well beyond the network hardware -- workstations are all Compaq, productivity software is Microsoft Office 97, databases are Oracle, and Netware's NDS ties it all together.

Although the general advantages of standardization made the support team's job that much easier, a key part of the change was the ability to smoothly manage the entire network.

"NDS is fabulous," Brand said. "I can administer my firewall, DHCP, proxy server, NT machines, single login, single password and all my printers from my desktop -- one machine, one program. I can create policies through NDS for Windows 95 and NT -- I can create a policy so that if a user changes their look on the desktop, within minutes, it can change back. If they delete a program it is back before they can blink -- NDS takes care of that."

To further the standardization, during the spring and summer, Brand intends to replace the financial and personnel applications with PeopleSoft programs. Currently, he is working on a project to connect all 700 field offices with frame relay -- putting Cisco routers and file servers in those locations, hooking up e-mail and mainframe access -- and establishing the support systems for the new network. He estimated that it will take about three years to complete the project.

With computer prices for performance seeming to always reach for new lows, refitting DHR's entire 41 floors, including networking equipment, was accomplished for under $1 million.

Although there's no silver bullet to move legacy data to the Web, Brand did have one piece of advice for managers facing a similar situation.

"With computers in a large organization, you have to standardize, and you have to standardize on the right equipment," Brand said. "Servers should be certified, workstations should be reliable. We could have 'saved' a lot of money by buying our own servers -- we tried that, and it was the most expensive server we ever bought. It kept going down and we had service calls. Do you know what's it like having a couple of thousand people not working? Not on my shift."

The Easier Route

Moving legacy systems to the Web is neither trivial nor impossible. Generally, there are two approaches to the problem: leave the legacy data intact and use existing products to translate from old to new, or replace the old entirely. By handling key parts of the problem with existing solutions -- such as routers that understand and can translate between older protocols and more Internet-friendly protocols -- the job is made far easier.


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David Aden is a senior consultant with webworld studios, a Virginia-based Web application development consulting company. Email
David Aden
David Aden DAden@webworldtech.com is a writer from Washington, D.C.