Welcome!

SDN Journal Authors: Pat Romanski, Destiny Bertucci, Liz McMillan, Elizabeth White, Amitabh Sinha

Related Topics: PowerBuilder

PowerBuilder: Article

Legacy Systems: To Extend or Not Extend

Legacy Systems: To Extend or Not Extend

In 1999 millions of dollars were spent preparing legacy systems for the dreaded Y2K meltdown. Thankfully, most of these core computer systems survived the 01/01/00 coding problem. However, businesses now face another issue regarding their legacy systems that in many ways will prove more challenging than simple Y2K code remediation.

IT managers today need to provide customers and employees with access to data stored in legacy systems via the Internet. Unfortunately legacy systems are not "Internet compatible." This leaves many IT organizations facing the question of whether to extend their legacy systems or scrap them in favor of a whole new system.

The good news is most companies probably won't have to destroy their legacy systems just to get on the Internet. There's this notion that because legacy systems are old, they need to be replaced. But if they survived Y2K, chances are they can be modified or "extended" to the Web. The difficult thing is figuring out the best way to get there.

Legacy systems aren't necessarily the big, black boxes we call mainframe systems. The technical definition is any core computer system that's integral to keeping a business running. A business could have a brand new core computer system, and it will still be a legacy system. For the purposes of this article we're talking about older technology, such as mainframes and newer client/ server systems.

The problem with the older legacy systems is that the Internet wasn't important when they were invented. So if companies want to integrate Web-based data retrieval and processing, they can't just hook up a T1 line. The process of providing Internet access to a legacy system is much more complex. That's why businesses think they need to scrap the old in favor of the new, which isn't always the case.

Companies are interested in Internet access to their legacy systems because customers are demanding 24/7 access to their information. For example, people are no longer satisfied with quarterly statements from their 401K plans. They want to be able to go online and get real-time information about their accounts. The same holds true for customers who want to know if a warehouse has a part in stock. They can look online and not worry about delays due to telephone tag or being placed on hold.

Today's world is more self-service. Businesses are running off the McDonald's model of "get your own straw and napkin" when it comes to data. If you're in the business of selling something, it's easier to let customers service themselves with Web access to your core business computer system.

Up until a few years ago, the only two solutions were to scrap the legacy system in favor of a new system or to rewrite all its coding. The word rewrite sends chills up most managers' spines because traditionally it takes lots of time and money. Another problem is many older legacy systems have "black box" logic, which is a big mystery to IT managers. The systems do their job but very few people know how their inner workings function. Huge costs were amassed in the 1990s as people tried to figure out how the old systems worked and struggled to rewrite the coding. These difficulties really left a bad taste in many a manager's mouth.

The good news is twofold. First, rewriting is less expensive now that procedures and precedents have been set over the past few years. Second, rewriting isn't the only solution that preserves a legacy system and makes it Web accessible. The other option is called extension. Instead of writing legacy code on new platforms, technology pros are integrating new platforms with the old legacy systems. This means having a new system running side-by-side with the old one with programs that allow the two systems to communicate.

The legacy system is preserved with little or no modification. Extending doesn't lead to a rewrite of the legacy system, rather it's reframed with phrase changes or new interfaces. When a legacy system is extended, a front end can be added so that customers have Web access to data and a back end, such as a data warehouse, or a business intelligence tool can be added. Either way, the core logic - the "black box" of the legacy system - is not modified.

There are drawbacks to extension. You'll create more complexity in your infrastructure because you're now work- ing with two platforms. In some cases the extension becomes so complex we actually recommend the company swallow the pill and rewrite the whole system. Also, if the IT manager isn't ready to manage a system with two platforms, it's time for a new system.

There are basically six options for a company with a legacy system that's looking to integrate new technologies into its core operations and get to the Web now.

Outside of Extending
1. Prepackaged Solutions
Prepackaged systems can be a great way to make the jump into a Web-based solution. What you do is buy the application, install it, get rid of your old system, and you're done. You have a front end on the Web, and you cut the ties to the old legacy system. These packages are very expensive; however, they aren't very customizable, and there could be a problem during transition. A company could be left helpless if a glitch develops along the way.

2. Automatic Rewriting
Tools exist that read your legacy code, such as COBOL, then rewrite it into Visual Basic or Java. This lets you completely rewrite your old system and move your core system into a Windows-based environment. The scary part comes into play when these types of programs encounter your legacy system's black box area. What happens if part of the black box coding is captured by the tool and rewritten incorrectly? Your system may be changed, and you won't even know until it's too late. This can lead to major problems for your business.

Extending
3. Screen Scraping or Enhanced Terminal Emulation
Screen scraping is the least expensive way to extend a system, plus it's fast and tactical. Basically you're using the protocols already in place and piggybacking a new operation on top. You'll have a dot.com component that lets you interface with the Web. However, you're stuck with whatever green screen you had in the first place. This means you can't modify the way you view or interface with the data. A screen scrape only allows you to hook the Web attachment onto the old system. It still looks the same, just Web-based. But if all you need is Web access and nothing fancy, screen scraping could work.

4. Wrapping
A wrap is what its name implies. The legacy system is wrapped by the new back and front ends. By doing this you ratchet up your complexity level. Typically, wrapping is a fine solution if you want to get data into or out of your mainframe via a new system. Wrapping is best suited for a batch-processing environment, such as taking customer orders. You can wrap a SQL system onto the front and back ends of the legacy system. Then create a Web application that takes that data and puts it into a SQL system that dumps into the mainframe several times a day.

The drawback of wrapping is that you can't get complex, real-time data. You can see if an order has been placed, but you can't check its details. Wrapping gives you a buffered legacy environment with new technologies that create a good Web connection. The information can be formed any way the company wants, unlike the limitations of screen scraping. The tradeoff is that the system is now more complicated.

Once legacy data has been restaged into a relational database environment, a variety of Internet development tools can be used to create new Web-based applications. The chosen development platform should be able to address as many back-end data sources as possible. For example, EAStudio from Sybase offers a back-end independent solution for Java development. While offering native drivers for Sybase and Oracle connections, it also provides broader database connectivity through JDBC and ODBC support. This is an attractive feature for managers considering a wrapping strategy to extend legacy data because it allows them to choose the best relational database for their organization. EAServer also provides connection pooling, which can dramatically increase application performance. Pooling of database connections is a must-have feature of any application server because establishing the initial connection is the single biggest drain on database-driven solutions.

Tool sets such as EAStudio also provide IDEs for Java development. Developers can visually create the inherently nonvisual server-side components they need to encapsulate business logic. Sybase has managed to use its mature PowerBuilder IDE for Java development as well. PowerBuilder really introduced the masses to the concept of encapsulating business-processing logic in software classes. Their IDE was one of the first to provide a visual metaphor for developing components. They've done a great job extending this into the Java development arena.

5. Middleware Solutions
Middleware provides direct programmatic access to legacy code and processes. To use middleware you typically introduce a server or middleware system that knows how to talk to the operating environment of the legacy system. Middleware solutions are more appropriate than screen scraping for most business applications.

However, they're technically more challenging and complex because you're brokering a new relationship between the new and old platforms. Middleware allows you to use Java or new languages to program new components to your legacy systems. It allows for real-time data access, which is important for transaction processes and things such as stock exchanges.

6. Enterprise Application Integration
EAI allows you to buy a package that does the entire extending process for you. For example, you have a legacy payroll system you'd like to get on the Web. You can buy an EAI that automatically does a front- and back-end extension for you. In theory, you can buy the package, put it in, and you're done. The drawback is you're stuck with whatever system the vendor likes. EAI may be quick, but it's certainly not easy to customize and is very costly.

Which solution is the best? It all depends upon your needs and how much money you have to fix the problem. But remember, if your legacy system is working, you may not have to change or replace it. If your core business hasn't changed and the access needs haven't changed, the answer is simple: don't touch it. If your customers or employees want to have Internet access to the data, you need to extend. Whatever choice you make, I recommend calling an outside consultant to look at your legacy set up and help determine the best way to apply the solution. Try to pick a solution that gives you as much flexibility and customization as possible.

The trick to extending legacy systems properly is to keep the business running while you modify the system to incorporate new applications, such as the Internet. Only when the traditionally inflexible core system has been made flexible can the process be declared a success. It can be done; the trick is finding the right solution for you.

More Stories By Stephen Laich

Stephen Laich is a senior solution developer at Pinnacle Decision Systems, a Microsoft Certified Solution Provider.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@CloudExpo Stories
Mobile device usage has increased exponentially during the past several years, as consumers rely on handhelds for everything from news and weather to banking and purchases. What can we expect in the next few years? The way in which we interact with our devices will fundamentally change, as businesses leverage Artificial Intelligence. We already see this taking shape as businesses leverage AI for cost savings and customer responsiveness. This trend will continue, as AI is used for more sophistica...
Nordstrom is transforming the way that they do business and the cloud is the key to enabling speed and hyper personalized customer experiences. In his session at 21st Cloud Expo, Ken Schow, VP of Engineering at Nordstrom, discussed some of the key learnings and common pitfalls of large enterprises moving to the cloud. This includes strategies around choosing a cloud provider(s), architecture, and lessons learned. In addition, he covered some of the best practices for structured team migration an...
Most technology leaders, contemporary and from the hardware era, are reshaping their businesses to do software. They hope to capture value from emerging technologies such as IoT, SDN, and AI. Ultimately, irrespective of the vertical, it is about deriving value from independent software applications participating in an ecosystem as one comprehensive solution. In his session at @ThingsExpo, Kausik Sridhar, founder and CTO of Pulzze Systems, discussed how given the magnitude of today's application ...
In his session at 21st Cloud Expo, Raju Shreewastava, founder of Big Data Trunk, provided a fun and simple way to introduce Machine Leaning to anyone and everyone. He solved a machine learning problem and demonstrated an easy way to be able to do machine learning without even coding. Raju Shreewastava is the founder of Big Data Trunk (www.BigDataTrunk.com), a Big Data Training and consulting firm with offices in the United States. He previously led the data warehouse/business intelligence and B...
The “Digital Era” is forcing us to engage with new methods to build, operate and maintain applications. This transformation also implies an evolution to more and more intelligent applications to better engage with the customers, while creating significant market differentiators. In both cases, the cloud has become a key enabler to embrace this digital revolution. So, moving to the cloud is no longer the question; the new questions are HOW and WHEN. To make this equation even more complex, most ...
As you move to the cloud, your network should be efficient, secure, and easy to manage. An enterprise adopting a hybrid or public cloud needs systems and tools that provide: Agility: ability to deliver applications and services faster, even in complex hybrid environments Easier manageability: enable reliable connectivity with complete oversight as the data center network evolves Greater efficiency: eliminate wasted effort while reducing errors and optimize asset utilization Security: imple...
In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, led attendees through the exciting evolution of the cloud. He looked at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering m...
With tough new regulations coming to Europe on data privacy in May 2018, Calligo will explain why in reality the effect is global and transforms how you consider critical data. EU GDPR fundamentally rewrites the rules for cloud, Big Data and IoT. In his session at 21st Cloud Expo, Adam Ryan, Vice President and General Manager EMEA at Calligo, examined the regulations and provided insight on how it affects technology, challenges the established rules and will usher in new levels of diligence arou...
The past few years have brought a sea change in the way applications are architected, developed, and consumed—increasing both the complexity of testing and the business impact of software failures. How can software testing professionals keep pace with modern application delivery, given the trends that impact both architectures (cloud, microservices, and APIs) and processes (DevOps, agile, and continuous delivery)? This is where continuous testing comes in. D
Modern software design has fundamentally changed how we manage applications, causing many to turn to containers as the new virtual machine for resource management. As container adoption grows beyond stateless applications to stateful workloads, the need for persistent storage is foundational - something customers routinely cite as a top pain point. In his session at @DevOpsSummit at 21st Cloud Expo, Bill Borsari, Head of Systems Engineering at Datera, explored how organizations can reap the bene...
Digital transformation is about embracing digital technologies into a company's culture to better connect with its customers, automate processes, create better tools, enter new markets, etc. Such a transformation requires continuous orchestration across teams and an environment based on open collaboration and daily experiments. In his session at 21st Cloud Expo, Alex Casalboni, Technical (Cloud) Evangelist at Cloud Academy, explored and discussed the most urgent unsolved challenges to achieve f...
The dynamic nature of the cloud means that change is a constant when it comes to modern cloud-based infrastructure. Delivering modern applications to end users, therefore, is a constantly shifting challenge. Delivery automation helps IT Ops teams ensure that apps are providing an optimal end user experience over hybrid-cloud and multi-cloud environments, no matter what the current state of the infrastructure is. To employ a delivery automation strategy that reflects your business rules, making r...
The 22nd International Cloud Expo | 1st DXWorld Expo has announced that its Call for Papers is open. Cloud Expo | DXWorld Expo, to be held June 5-7, 2018, at the Javits Center in New York, NY, brings together Cloud Computing, Digital Transformation, Big Data, Internet of Things, DevOps, Machine Learning and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding busin...
In a recent survey, Sumo Logic surveyed 1,500 customers who employ cloud services such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP). According to the survey, a quarter of the respondents have already deployed Docker containers and nearly as many (23 percent) are employing the AWS Lambda serverless computing framework. It’s clear: serverless is here to stay. The adoption does come with some needed changes, within both application development and operations. Tha...
SYS-CON Events announced today that Synametrics Technologies will exhibit at SYS-CON's 22nd International Cloud Expo®, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Synametrics Technologies is a privately held company based in Plainsboro, New Jersey that has been providing solutions for the developer community since 1997. Based on the success of its initial product offerings such as WinSQL, Xeams, SynaMan and Syncrify, Synametrics continues to create and hone in...
Smart cities have the potential to change our lives at so many levels for citizens: less pollution, reduced parking obstacles, better health, education and more energy savings. Real-time data streaming and the Internet of Things (IoT) possess the power to turn this vision into a reality. However, most organizations today are building their data infrastructure to focus solely on addressing immediate business needs vs. a platform capable of quickly adapting emerging technologies to address future ...
In his general session at 21st Cloud Expo, Greg Dumas, Calligo’s Vice President and G.M. of US operations, discussed the new Global Data Protection Regulation and how Calligo can help business stay compliant in digitally globalized world. Greg Dumas is Calligo's Vice President and G.M. of US operations. Calligo is an established service provider that provides an innovative platform for trusted cloud solutions. Calligo’s customers are typically most concerned about GDPR compliance, application p...
Kubernetes is an open source system for automating deployment, scaling, and management of containerized applications. Kubernetes was originally built by Google, leveraging years of experience with managing container workloads, and is now a Cloud Native Compute Foundation (CNCF) project. Kubernetes has been widely adopted by the community, supported on all major public and private cloud providers, and is gaining rapid adoption in enterprises. However, Kubernetes may seem intimidating and complex ...
In his session at 21st Cloud Expo, Michael Burley, a Senior Business Development Executive in IT Services at NetApp, described how NetApp designed a three-year program of work to migrate 25PB of a major telco's enterprise data to a new STaaS platform, and then secured a long-term contract to manage and operate the platform. This significant program blended the best of NetApp’s solutions and services capabilities to enable this telco’s successful adoption of private cloud storage and launching ...
You know you need the cloud, but you’re hesitant to simply dump everything at Amazon since you know that not all workloads are suitable for cloud. You know that you want the kind of ease of use and scalability that you get with public cloud, but your applications are architected in a way that makes the public cloud a non-starter. You’re looking at private cloud solutions based on hyperconverged infrastructure, but you’re concerned with the limits inherent in those technologies.