Microservices: How to Turn One Bug Into a Thousand

December 18, 2023

7 min read

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Microservices are like the popular kids of the software world. Everyone wants to be seen with them, everyone’s talking about them, and adopting them seems like a ticket to coolness and “scalability”. But, let’s be real: microservices can quickly turn your codebase into a sprawling mess of tiny, interconnected bugs that cascade through your system like a game of broken telephone. You fixed one bug? Great, now 37 more just popped up in services you didn’t even know existed. Welcome to the wonderful world of microservices, where complexity scales like a pro!

If you’re thinking about diving headfirst into microservices, here’s a guide on how to turn your simple monolithic bug into a thousand tiny nightmares.

1. Distributed Bugs for a Distributed System

Microservices seem simple enough on paper. Break your monolithic app into smaller, independently deployable services. Sounds great, right? But remember, with great independence comes great complexity. Suddenly, a bug in one service isn't just a bug in one service. It’s a bug that can ripple across the entire system, manifesting in 10 different ways in 10 different services.

Here’s how it happens: a single null pointer exception in Service A leads to bad data getting sent to Service B. Service B happily processes that garbage data and then passes it on to Service C, which gracefully chokes on it, sending back a 500 error. Now, Services D through Z are throwing alarms because Service C is down. You thought you were debugging a minor issue in Service A? Congratulations, you’re now tracing issues across your entire system. Hope you’ve got good monitoring (and a lot of coffee).

2. The Cascade of Chaos: Where Bugs Breed Bugs

In a monolith, you’d find your bug, fix it, deploy, and call it a day. With microservices, bugs tend to breed faster than rabbits. One bug creates side effects that cause failures in multiple downstream services, and each of those services might have its own issues that complicate debugging even further.

Let’s say you have a simple bug in your payment service. It messes up data formatting, which causes the order service to freak out. Now the shipping service is panicking because it didn’t get the right order status. Your customer notification service, ever the overachiever, is emailing users to let them know that their payments failed… even though they didn’t. And your logging service, trying to keep up, just throws up its hands and stops working entirely. A simple bug turns into a distributed systems whack-a-mole marathon.

3. APIs: The True Breakpoint in Microservices

Microservices rely heavily on APIs for communication, which means your bug count isn’t just limited to what happens inside each service. It now includes the fun world of API version mismatches, timeouts, and network failures. Every single interaction between services is a potential point of failure, and each of those failures can give birth to entirely new bugs.

Versioning hell is real. Service A is running API v1.0, but Service B is expecting v1.1. Suddenly, a simple bug is now about resolving API contracts, fixing data formats, and redeploying half the services to align on a common protocol. And let’s not forget network issues! You didn’t think distributed systems would communicate without occasional packet loss, did you? Slow responses, retries, and timeouts are the breeding ground for a whole new category of bugs that make you long for the simpler days of in-memory method calls.

4. The Joy of Data Inconsistency

Ah, data consistency—something that’s so simple in a monolith and somehow an unsolvable riddle in a microservice architecture. With microservices, each service might manage its own database. While that’s great for scalability and independence, it’s not so great for data consistency. You’re now in a world where two services might have conflicting views of the same data at the same time. Fun!

One bug in a single service can corrupt data in its database, which might not sync correctly with other services. Then you’ve got different parts of your system relying on out-of-date or incorrect data. One service might tell you a user has paid, while another service shows that the payment is still pending. Who’s right? The answer: no one. Now you’re stuck tracing data through event logs, message queues, and database states trying to figure out where it all went wrong. (Spoiler: it went wrong the moment you broke your monolith into microservices.)

5. Monitoring, Logging, and the Search for Meaning

In the good ol’ days of monolithic applications, you had a single log file, and if something broke, you could search that file and find the problem. In a microservices architecture, you’ll have dozens of logs spread across dozens of services, all deployed across various nodes. So, when something goes wrong—and it will—you’ll be spending a solid chunk of your day (or week) combing through logs, hunting down the needle-in-a-haystack bug that’s causing the chaos.

Add to that the fact that logs often don’t paint a full picture. One service might log an error that doesn’t seem connected to another service’s failure, but in reality, they’re part of the same issue. Now you’re stuck piecing together a narrative from disjointed logs spread across multiple systems, like some sort of tragic tech detective in a debugging noir film.

6. Multiple Points of Failure? Yes, Please!

Why settle for one point of failure when you can have dozens? Microservices architecture doesn’t just distribute responsibility across services; it distributes failure points too! Now, instead of worrying about a bug bringing down one system, you can have bugs and failures pop up in every service. A bad deploy in any one of your dozens of services can take down a critical part of your app. And if your microservices don’t handle failure gracefully (hint: they won’t), you’ve now got cascading failures on your hands.

Remember that small bug in the user authentication service? Well, now no one can log in, and because your authentication service is down, your billing system is stalling, and your entire e-commerce platform is suddenly unreachable. Multiple points of failure scale quickly—and disastrously.

7. The Team Scaling Myth: Many Services, Many Owners

One of the most touted benefits of microservices is that teams can own their own services, deploy independently, and scale the development process. What they don’t tell you is that teams will now be too busy fixing bugs in their own services, debugging cross-service failures, and untangling inter-service dependencies to actually build new features.

That promise of independent ownership? It turns into a nightmare of finger-pointing when bugs hit the fan. “It’s not us, it’s Service C.” “No, it’s Service A!” The curse of microservices is that teams will be more concerned with defending their turf than collaborating to solve the root issues. Meanwhile, the bugs keep multiplying like some sort of digital Hydra—fix one, and two more take its place.

Conclusion: Microservices Done Right (Or Not)

Don’t get me wrong—microservices have their benefits. They can help with scalability, allow for independent deployments, and isolate failures (in theory). But if not done carefully, they can also create a tangled web of bugs that spread through your system faster than a chain reaction. Debugging in microservices is like playing an endless game of “Guess Who?” where every service hides a little piece of the problem.

So, before you jump on the microservices bandwagon, ask yourself: “Do I really want to scale my complexity like a pro?” Or, better yet, ask yourself if you have the team, infrastructure, and mental fortitude to deal with turning one bug into a thousand. Because if you don’t, the curse of microservices might be coming for you.