Is Mainframe A Dying Technology? In Defense Of The Mainframe!
Technology
Workloads are old, not the Mainframe
Did that statement surprise you? Why do I say that workloads are old and not the mainframe? Let’s think about that for a moment – does it make sense to you? Do you agree with it? What immediate thoughts does it spark?
Most of us think of the mainframe as ancient technology, but I would like to change your thinking and show you why it is the concept of workloads that is truly old and not the mainframe itself.
As you probably know, mainframe encompasses the underlying infrastructure supporting applications, workloads, and business logic – but did you know that, as of right now, mainframe is the only information technology that has maintained backward compatibility? Mainframes first came into existence in the mid-1960s, which means that for more than 55 years, mainframe technology has maintained backward compatibility – no other technology can lay claim to that feat.
You may be thinking, “So what? Why is that a big deal? What is backward compatibility anyway?”
Backward compatibility simply means that each time there is any level of infrastructure upgrade required, your applications, workloads and business logic will continue to function without the need for them to be upgraded as well – which is obviously a huge benefit.
Mainframe, also known as IBM Z series, has gone through dozens of processor and other hardware upgrades such as built-in storage, memory, built-in network, and other components. In addition to hardware upgrades, software upgrades have been introduced; upgrades include new features and functionalities along with faster and better performance.
To help illustrate, let’s look at the high-level architecture diagram below. (this diagram was copied from the Microsoft Azure website as I find it very easy to follow visually).
Over the decades, zOS (Operating System), along with data stores such as IMS, VSAMS, and DB2 have seen numerous upgrades. Other middleware such as Transaction Manager components (CICS and IMS) also have been upgraded multiple times, along with Job Control Language (JCL.) As part of ongoing zOS upgrades, System Management tools have become upgraded and enhanced. Last but not least, programming languages such as COBOL, PL/1, Assembler, Fortran, and others have seen their share of upgrades and enhancements as well.
Backward compatibility ensures that while the underlying hardware and software components may change or upgrade, the code you wrote a few years ago or a decade ago will still run without requiring any modifications or upgrades. I have personally worked with many clients who upgraded their mainframe infrastructure dozens of times and never had to change a single line of their application code. Even more astonishing, some of our clients continue to run their business logic on Mainframe even though they do not have the source code; they are able to run compiled code without any disruption.
Mainframe has done an amazing job of maintaining the longest running backward compatible technology in human history.
Current mainframe processors and other hardware components are some of the most advanced technology available in the industry; not only does mainframe facilitate running Linux OS in native mode, it also facilitates containers (including Kubernetes containers) in native mode.
Backward compatibility has ensured that mainframe customers have not had to suffer disruptions over many decades; however, due to this, it has also spawned the existence of very old workloads. Since mainframe customers rarely put much effort into modernizing their applications and workloads.
That brings me to my opening statement – Workloads are old, not the mainframe.
When faced with modernizing mainframe workloads. I highly recommend that you give some serious thought to rewriting and refactoring applications on Linux as well as containers.
Which will help you create microservices-based applications. Mainframes will continue to be the backbone for many enterprises for the foreseeable future, so it would be wise to modernize workloads wherever possible.
Fun fact: While Python, Java, and C language variants have become prominent in the last two decades. COBOL still holds the title of the most number of lines of code used across all enterprises worldwide; some estimates put the number of lines of COBOL code in use today at 200 billion!
As always, I hope this article was of value to you, and would love to hear your thoughts in the comments section below. Feel free to share this article with your network. However, please note that all views expressed in here are that mine and do not represent Kyndryl’s official positions.
