Stories about Software


What Problems Do Microservices Solve?

Editorial note: I originally wrote this post for the TechTown blog.  You can check out the original here, at their site.  While you’re there, have a look at the tech courses they offer.

Do you find that certain industry buzzwords set your teeth on edge?  If so, I assure you that you have company.  Buzzwords permeate every professional space, but it seems that tech really knows how to attract them.  Internet of things.  The cloud.  Big data. DevOps.  Agile and lean.  And yes, microservices.

Because of our industry’s propensity for buzzwords, Gartner created something it calls the hype cycle.  It helps their readers and clients evaluate how much attention to pay to emergent ideas.  They can then separate vague fluff from ideas that have arrived to stay.  And let’s be honest — it’s also a funny, cathartic concept.

If you’ve tired of hearing the term microservices, I can understand that.  As of 2016, Gartner put it at the peak of inflated expectations.  This means that the term had achieved maximum saturation a year ago, and our collective fatigue will drive it into the trough of disillusionment.

And yet the concept retains value.  Once the hype fades and it makes its way toward the plateau of productivity, you’ll want to understand when, how, and why to use it.  So in a nod toward pragmatism, I’m going to talk about microservices in terms of the problems that they solve.

First, What Are Microservices?

Before going any further, let me offer a specific definition.  After all, relying on vague, hand-waving definitions is the main culprit in buzzword fatigue.  I certainly don’t want to contribute to that.

Industry thought leader Martin Fowler offers a detailed treatment of the subject.

In short, the microservice architectural style [1] is an approach to developing a single application as a suite of small services, each running in its own process and communicating with lightweight mechanisms, often an HTTP resource API. These services are built around business capabilities and independently deployable by fully automated deployment machinery.

Now, understand something.  The architectural trade-off here is nothing new.  In essence, it describes centralizing intelligence versus distributing it.  With a so-called monolith, clients have it easy.  They call the monolith, which handles all details internally.  When you distribute intelligence, on the other hand, clients have more burden to figure out how to compose calls and interactions.

The relative uniqueness of the microservices movement comes from taking that tradeoff and layering atop it delivery mechanisms and the concept of atomic business value.  Organizations touting valuable microservices architectures tend to offer them up over HTTP and providing functionality that stands neatly alone.  (I make the distinction of valuable architectures since I see a lot of shops just call whatever they happen to deliver a microservices architecture.)

For example, a company may offer a customer onboarding microservice.  It can stand alone to create new customers.  But clients of this service, internal and external, may use it to compose larger, more feature-rich pieces of functionality.

So, having defined the architectural style, let’s talk about the problems it solves.

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The Most Commonly Reinvented Wheels in Software

Editorial note: I originally wrote this post for the Telerik blog.  You can check out the original here, at their site.  While you’re there, take a look at their developer tools and controls offerings — they’re quite extensive.

If you ever want to set off a heated argument among software developers, you could do worse than to ask about “build vs buy.”  This one touches the third rail to such an extent that it has many colloquial names attached to it.

If you want to see this debate in action, plenty of venues exist.  Developers may accuse one another of reinventing the wheel, only to hear that some wheels need reinventing for various reasons.  Opponents of the practice have even described it as a syndrome, called “not invented here syndrome.”  But I have also seen proponents turn the tables and call out “not ever invented here syndrome” to describe software shops that awkwardly buy when building makes more sense.

Suffice it to say opinions abound and no clear consensus exists.  The highly context-specific nature of a given example also muddies the waters.  What makes sense for your team in your situation may not apply to another team.

I’ve offered thoughts on navigating this issue in another post.  Today, I’d like to avoid controversy.  I won’t weigh in on whether reinventing wheels makes sense because it deepens your knowledge or whether it wastes time and money.  Instead, I’m just going to catalog the most frequent examples I see of wheel reinvention.  As a consultant that specializes in assessing codebases and application portfolios, I see a lot of code.  This gives me a bird’s eye view of what shops love to write themselves.

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Rewrite or Refactor?

Editorial Note: I originally wrote this post for the NDepend blog.  You can find the original here, at their site.  While you’re there, take a look at some of the other posts and announcements.  

I’ve trod this path before in various incarnations, and I’ll do it again today.  After all, I can think of few topics in software development that draw as much debate as this one.  “We’ve got this app, and we want to know if we should refactor it or rewrite it.”

For what it’s worth, I answer this question for a living.  And I don’t mean that in the general sense that anyone in software must ponder the question.  I mean that CIOs, dev managers and boards of directors literally pay me to help them figure out whether to rewrite, retire, refactor, or rework an application.  I go in, gather evidence, mine the data and state my case about the recommended fate for the app.


Because of this vocation and because of my writing, people often ask my opinion on this topic.  Today, I yet again answer such a question.  “How do I know when to rewrite an app instead of just refactoring it?”  I’ll answer.  Sort of.  But, before I do, let’s briefly revisit some of my past opinions.

Getting the Terminology Right

Right now, you’re envisioning a binary decision about the fate of an application.  It’s old, tired, clunky and perhaps embarrassing.  Should you scrap it, write it off, and start over?  Or, should you power through, molding it into something more clean, modern, and adaptable.  Fine.  But, let’s first consider that the latter option does not constitute a “refactoring.”

A while back, I wrote a post called “Refactoring is a Development Technique, Not a Project.”  You can read the argument in its entirety, but I’ll summarize briefly here.  To “refactor” code is to restructure it without altering external behavior.  For instance, to take a large method and extract some of its code into another method.  But when you use “refactor” as an alternative to “rewrite,” you mean something else.

Let’s say that you have some kind of creaky old Webforms application with giant hunks of gnarly code and logic binding the GUI right to the database.  Worse yet, you’ve taken a dependency on some defunct payment processing library that prevents you from updating beyond .NET 2.0.  When you look at this and say, “should I refactor or rewrite,” you’re not saying “should I move code around inside this application or rewrite it?”  Rather, you’re saying, “should I give this thing a face lift or rewrite it?”

So let’s chase some precision in terms here.  Refactoring happens on an ongoing and relatively minor basis.  If you undertake something that constitutes a project, you’re changing the software.  You’re altering the way it interacts with the database, swapping out a dependency, updating your code to a new version of the framework, etc.  So from here forward, let’s call that a reworking of the application.

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