Legacy IT Infrastructure: Not the Villain We Make It Out to Be
The tried-and-true reliability of legacy systems often outweighs the allure of modern alternatives, challenging us to reconsider what "legacy" truly means in today's IT landscape.
At a Glance
- Legacy IT infrastructure offers proven reliability and stability that newer, untested solutions cannot match.
- Finding qualified staff for legacy systems is often easier due to their widespread historical use.
- Maintaining legacy systems can be more economical than undertaking migrations that may introduce unforeseen challenges.
In the realm of IT infrastructure, legacy can often feel like a bad word. No one wants to be told their organization is stuck with legacy IT infrastructure because it implies that it's old or outdated.
Yet, when you actually delve into the details of what legacy means in the context of servers, networking, and other infrastructure, a more complex picture emerges. Legacy isn't always bad.
To prove the point, let's take a closer look at what legacy IT infrastructure means and the pros and cons it offers in areas like scalability, cost, security, and beyond.
What Is Legacy IT Infrastructure?
Legacy IT infrastructure is a generic term for IT systems, including both hardware and software, that may be considered out of date or no longer fit for use.
Legacy infrastructure is generally defined by characteristics like the following:
Lack of active vendor support: If the original vendor no longer supports a system, it may be a sign that it has entered the realm of legacy hardware or software.
Limited scalability: Systems that are challenging to scale, such as on-prem servers , may fit the definition of legacy infrastructure because they offer less flexibility than alternatives.
Security risks: IT infrastructure subject to inherent security flaws is often considered legacy. A classic (albeit dated) example is wireless routers that only support encryption based on the WEP protocol, which has been easily crackable for more than a decade.
Integration challenges: Systems that are difficult or impossible to integrate with other systems — such as hardware that requires a specific, proprietary operating system — may be considered legacy in some cases.
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These drawbacks can make legacy systems more complicated to maintain. They can also reduce their reliability and make them less cost-effective. This is why legacy frequently carries a negative connotation in the IT ecosystem.
The Ambiguous Meaning of Legacy Infrastructure in IT
That said, the challenging thing about defining legacy IT infrastructure with precision is that many of the characteristics listed above apply to infrastructure that may be considered "modern." They're not exclusive to older hardware or software.
For instance, plenty of applications, databases, and so on depend on proprietary software that is difficult to integrate with third-party solutions. But in many cases, these aren't labeled legacy systems. We just call them examples of vendor lock-in.
Likewise, most open source software — which now helps to power virtually every application in existence — is not actively supported by a vendor. Open source is typically freely available code that organizations may choose to use at their own risk. But that doesn't mean that open source systems are legacy.
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Why Legacy IT Systems Aren't Always Bad
What's more, it's not necessarily the case that a system is bad, or in dire need of replacement, just because it fits the classic definition of legacy IT. There's an argument to be made that, in many cases, legacy systems are worth keeping around.
For starters, most legacy infrastructure consists of tried-and-true solutions. If a business has been using a legacy system for years, it's a reliable investment. It may not be as optimal from a cost, scalability, or security perspective as a more modern alternative. But in some cases, this drawback is outweighed by the fact that — unlike a new, as-yet-unproven solution — legacy systems can be trusted to do what they claim to do because they've already been doing it for years.
The fact that legacy systems have been around for a while also means that it's often easy to find engineers who know how to work with them. Hiring experts in the latest, greatest technology can be challenging, especially given the widespread IT talent shortage . But if a technology has been in widespread use for decades, IT departments don't need to look as hard to find staff qualified to support them.
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From a cost perspective, too, legacy systems have their benefits. Even if they are subject to technical debt or operational inefficiencies that increase costs, sticking with them may be a more financially sound move than undertaking a costly migration to an alternative system, which may itself present unforeseen cost drawbacks. (This is a lesson that some organizations that have undergone cloud repatriation learned the hard way; they moved to the cloud in a bid to save costs, only to move back because they discovered that the cloud doesn't always yield the best bang per IT buck.)
As for security, it's hard to argue that a system with inherent, incurable security flaws is worth keeping around. However, some IT systems can offer security benefits not available on more modern alternatives. For instance, mainframes are generally less likely to be targeted by threat actors simply because there are many fewer of them in operation. In this sense, using legacy mainframe infrastructure can help reduce the likelihood that an organization will face a ransomware attack or data breach. (To be clear, mainframes can be hacked, just like any other IT systems, but they're less frequent targets than are modern systems that are more widely used.)
Learning to Love Legacy IT
None of the above is to say that legacy IT systems should keep running forever. Some legacy infrastructure is just too inefficient or risky to keep around.
But it is to say that legacy IT infrastructure isn't always evil, or in need of replacement at the first opportunity. Sometimes, it makes more sense to keep legacy systems around — and for IT teams to rethink what legacy even means in the first place.
About the Author
Technology analyst, Fixate.IO
Christopher Tozzi is a technology analyst with subject matter expertise in cloud computing, application development, open source software, virtualization, containers and more. He also lectures at a major university in the Albany, New York, area. His book, "For Fun and Profit: A History of the Free and Open Source Software Revolution ," was published by MIT Press.
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