It can take a bit of work, but you can move your legacy COBOL applications to the cloud.

Guest Commentary, Guest Commentary

April 28, 2017

4 Min Read

Let’s talk about your COBOL applications.  We know, it’s tough to let go. They’ve been with you for a long time. People keep telling you to deploy some new packaged application or to rewrite your COBOL applications in a more modern language, but those old COBOL applications work like nothing else.

It may be less costly to run some packaged app in the cloud, and you might gain a level of processing and storage elasticity that you don’t have now. The cloud could radically cut the cost of disaster recovery and the cost of maintaining failover systems, but it’s still hard to change. Those COBOL applications are tested and proven, shaped to conform to the contours of your business like no off-the-shelf app running in the cloud is ever going to be.

So here’s the happy news: All those advantages associated with the cloud — lower costs, elasticity, reduced risk. They can be yours, and you don’t need to rewrite your COBOL applications or invest in some new packaged app. You just need to move those COBOL applications into the cloud.

If the terms “COBOL” and “mainframe” have for years seemed inseparable, it may take a moment to get your head around this idea. No, there’s no mainframe in the cloud, at least, not literally. But you can build a virtual mainframe in the cloud, and from that virtual mainframe, you can run your existing COBOL applications.

Cloud environments such as Microsoft Azure and Amazon Web Services can provide an entire infrastructure as a service (IaaS). That infrastructure can be configured to run your COBOL applications as though they were running on a mainframe or in a distributed Windows/UNIX/Linux configuration (if that’s how you’re now running them).

You’ll have to do a bit of work to move your COBOL applications into the cloud, but far less than you might think. You’ll need to recompile your COBOL applications to run on a new target machine. There are edit, debug and test stages to ensure that your applications do what they’re supposed to do in the new virtualized environment. A few components will need to be rewritten (Assembler is always rewritten), but the majority of your code will be just fine. You’ll need to configure the cloud-based virtual machines upon which your applications will run, and that will involve creating an appropriate COBOL run-time environment, but there are modern tools and wizards that can help you along the way. These tools can help you map your COBOL applications to appropriate resources — from databases to print queues and more — as well as tools to help you upload and QA test your COBOL applications within the virtual machine environment before you go live. With assistance from a knowledgeable partner, this is an entirely manageable process — and one that takes only a fraction of the time that a rewrite or the greenfield deployment of a new package would take.

The outcome? You can continue to use the COBOL applications that have helped make your organization what it is. You can build on the business processes you already have in place. You can lower your operating and capital costs, gain the elasticity you need during those times of peak demand, and take advantage of a new cloud infrastructure to innovate.


Oh, did I mention performance? The COBOL modernization projects in which we’ve been involved have seen application run-time performance improve as a result of moving to the cloud. You simply have more leeway in configuring and tuning the VM to provide optimal support for your application. You may need to reconsider how the application interacts with third-party components or uses older languages, but if you had a speedy COBOL app interacting with responsive VSAM files before, you’re going to have a speedy COBOL app and responsive VSAM files in the cloud — perhaps even speedier and more responsive than you’ve seen before.

So, don’t give up your commitment to COBOL. Give up the big iron and move your COBOL applications to the cloud instead. You’ll gain the benefits that only the cloud can deliver, and you’ll give up a lot of the headaches and costs associated with that legacy hardware in your basement.

Craig Marble is the senior director of cloud consultancy Astadia’s legacy modernization practice. Craig has spent over 25 years in the information technology industry, most of which has been focused on legacy modernization projects.

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Guest Commentary

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