For many businesses, legacy app migrations are becoming an increasingly important issue when they examine their technology portfolios. But this is often easier said than done. Legacy apps have become one of the enduring points of pain, as the cost and difficulty in managing them within a large portfolio of applications leads to companies needing to prune and rationalize them on regular basis.
The whole prospect of how to exploit the cloud has added pressure on how to migrate a portfolio of legacy applications. The opportunities the cloud presents for increasing automation, enabling rapid innovation, and reducing operational costs are tantalizing. The cloud can also help solve operational problems with existing apps.
Yet to achieve this, companies must figure out which applications must be migrated in which order to make their cloud migration smooth. I’ve written about this before and there are a number of products on the market that help companies manage this migration. and that’s the root of the problem of legacy app migration.
Recently, I’ve had the chance to speak with the team from Pivotal about this issue. (At Early Adopter Research, my technology research company, we covered this topic in greater length in this story.) Pivotal offers a cloud-based platform for companies to run their applications. Originally, Pivotal thought that the majority of their clients and subsequent work streams would be focused on creating and supporting net new applications on their platform architecture. Instead, they’ve been surprised at how many of their clients are interested in using the Pivotal platform to manage their legacy application migration.
“Legacy app migration can be a challenge,” said Chuck D’Antonio of Pivotal. “But once you begin the process, you start to see things happen in production a little bit after that, on a timeline of weeks rather than what used to be months and years, and then you get that energy sort of folded back in. So in the same way you’re building knowledge, you get the power of that energy building up too, and the migration becomes less discouraging.”
Their experience working with these clients provides instructive guidance on how to effectively migrate legacy apps and the benefits of doing so.
Problems With Migrating Legacy Applications
Legacy app migration projects bring up the question of which applications to kill off and which to move. Killing off unworthy apps is more of a political problem than a technical one. But for the ones you are moving the questions become:
- Which do you lift and shift?
- Which do you refactor in some small way?
- Which do you really break apart and reassemble?
From a business perspective, the challenge is to decide where a better app will really help the business, which is never an easy task. From a technical perspective, the question often becomes how to migrate an app with a monolithic architecture to a more modern microservice structure.
To do a good job, I think it is important not to hate monolithic architectures. Pivotal’s John Ferguson agrees that we must understand the value in monolithic architectures. “The monolith really represents decades of learnings around how the business works, how the markets work, and the types of things that they need to offer. You shouldn’t get rid of those learnings altogether,” said Ferguson.
For Pivotal, to make it possible to evolve monolithic applications, innovate, and allow their capabilities to be used by other applications, the monolith must be broken apart into simpler component parts. “We call it strangling the monolith,” said Ferguson. See the Early Adopter Research story for a detailed discussion of specific strategies.
The Forces Accelerating Legacy App Migration
Based on my conversations with Pivotal, it seems that companies will go through three essential stages during a migration program.
- At first, they just want to gain operational efficiency and make their systems more resilient.
- They then recognize they can get their apps to run more reliably and with greater scalability.
- This leads to greater agility in general.
“We’ve found that the operational efficiencies of working with the abstraction levels of our platform are so great that the really big driver for our customers and actually for us, economically, too, is the migration of legacy apps, with some refactoring onto the platform,” said Rob Mee, Pivotal’s CEO.
Having a legacy application run on Pivotal avoids many of the problems that companies have using anachronistic architectures to support their legacy applications, like:
- Scaling
- Having to babysit and devote a lot of resources to the application to ensure it runs correctly
- Having to wait to see results once the migration occurs
This type of migration can lead to dramatic changes in a company’s culture, with people more invested in their work. Teams that have the context knowledge to make changes are finally given the power to do so.
“We’ve seen that as people decompose these services, they become much more autonomous, meaning the teams themselves are really empowered to act,” said Ferguson. “And I think that’s interesting, particularly in the enterprise world where they’re taking these large legacy systems and decomposing them, and when they do, the team structure, the organizational structure, is changing dramatically because it has to. The idea is that you’re empowering people to contribute to this ecosystem and then the ecosystem is growing. And even more important is getting that authority to the team to make the right services and to make the decisions about their services based on the demand for those services.”
These downstream cultural benefits to legacy app migration are just as important as the technological ones. And once legacy app migration begins to occur on some apps, the entire process accelerates. As Ferguson told me, the point is to “just get started.” Don’t worry about doing it all at once; just focus on doing something.
According to Pivotal, the typical Fortune 500 customer they work with has thousands of apps. Some of their customers have already migrated more than 5,000 apps with Pivotal’s platform. But they started small and worked their way through their migrations step by step. The benefits accumulate over time and the entire process becomes easier with each migration.
