When your system starts to “cough”: some random thoughts on Java microservices architecture

I remember the last time I chatted with an old friend, he managed a small automation equipment factory. That afternoon, he leaned on the railing on the second floor of the workshop, pointed to a row of robotic arms being debugged below, and said: "Look, every servo is very obedient. It will never turn 16 degrees if it turns 15 degrees. But what about the business system in my office? Adding a new function is like replacing parts for an old machine - the entire production line has to stop."

The scenario he described may be familiar to you: a single application that has been used for several years ran very fast at first, but gradually became bloated. Every time I update, I feel terrified, fearing that the slightest move will affect my whole body. New features are slow to come online, and troubleshooting is like finding the exit in a maze. Developers on the team increasingly spend their time tinkering instead of creating new things.

This is probably why more and more people have started talking about microservices in recent years.

Microservices are not "separation", but let the system learn to "collaborate"

Imagine a production line in your workshop. If there is only one master control switch for the entire line and one piece of equipment fails, the entire line will have to stop. But what if each piece of equipment—feeding, assembly, and inspection—had its own independent control system, with workpieces and information communicated through clear interfaces between them? When one piece of equipment is maintained, other equipment can operate as usual; when a certain link is upgraded, there is no need to shut down the entire line.

What the Java microservice architecture does is similar things. Split a huge single application into a set of small, independent services. Each service is built around specific business functions, uses its own database, and is deployed and scaled independently. They chat through a lightweight communication mechanism (usually HTTP or message queue).

Some people may ask: Isn’t this just splitting my original big program into many small programs? What's so special?

The difference lies in the word "independent". In true microservices, each service can be independently developed, deployed, and expanded independently. Just like that screw-driving robot in your workshop, you can upgrade its vision alone without having to touch the welding robot's programming. What this independence brings is the resilience of the system as a whole.

Why Java? And those "buts" that have to be said

Java seems to be a natural choice in this field. It is mature and has a rich ecosystem. From Spring Boot to various cloud native tool chains, there are too many supports. Just like the easiest-to-use wrench in your tool box, it may not necessarily be the flashiest, but you know it will be reliable in most situations.

But the road to microservices is not always smooth.

After splitting into services, network communication became inevitable. Services call each other, and if not managed well, it will become an unclear spider web. A problem spreads like a ripple, making it a headache to track. There is also data consistency - transactions that could be handled in one database in the past may now involve multiple services. How to ensure that the data is accurate?

This leads to the core of architecture: design. Microservices are not to be dismantled for the sake of dismantling, they need clear boundaries. Is it based on business ability? Or is it based on bounded context in domain-driven design? If you divide it too coarsely, you won't be able to enjoy flexibility; if you divide it too finely, the complexity of operation and maintenance will increase exponentially. There is no standard answer here. Just like designing a production line, it depends on what you specifically produce.

Some fragmented, non-linear practice fragments

Regarding technology selection, people often say “the right one is the best”. This is true, but how do you know if it is suitable? Sometimes, you can start with a small point. There is no need to ambitiously refactor the entire system from the start. Choose a module with relatively clear boundaries and relatively independent functions, and separate it into an independent service. Look at how it performs when deployed independently and scaled independently. Feel the changes in the CI/CD process brought about by this. Experience the adjustments needed for monitoring and log collection.

It's a bit like debugging a newly arrived servo motor. You don’t come up and just hook it up to the whole line and run it full speed. You will first test its speed, torque, and response curve individually. After figuring out its temperament, let it integrate into the entire system.

In terms of communication methods, synchronous calls (such as REST) ​​are simple and straightforward, but will increase coupling; asynchronous messages (through message queues) can decouple and improve resilience, but the architecture and debugging will be more complex. There are no silver bullets, only trade-offs.

As for deployment, containerization (such as Docker) has almost become the standard for microservices. It packages the application and its running environment together to ensure that "it can run in my place and it can run in your place". Combined with container orchestration tools, service online, rollback, expansion and contraction can become as intuitive as adjusting device parameters.

So, what does it bring? a short question and answer

Question: What’s the point of going all this way? Answer: The picture is that the system can keep up with business changes. Today you may need to add a new payment channel to the order service, and tomorrow you may need to connect new identity authentication methods to user management. If they are all intertwined code in a single body, every change must be made carefully. With a standalone service, you can be more focused and responsive.

Q: Will the team structure change? Answer: It tends to change accordingly. In the past, teams could be divided into front-end, back-end, and database teams. Now it is more likely to be divided by business areas, such as "order team" and "inventory team". Each team has higher autonomy over the services it is responsible for, and is responsible for the entire life cycle from development to operation and maintenance. This reduces waiting and wrangling between teams.

Q: What's the cost? Answer: The complexity is transferred from within the code to between services. You need more powerful monitoring to observe the entire system link, better log collection to trace problems, and handling of data consistency and network failures in a distributed environment. The skill requirements for operation and maintenance have shifted from managing servers to managing service clusters.

Written in: On Reliability Vs.kpowerchoice

Just like choosing a power core for precision machinery, the architectural cornerstone of the system also needs to be absolutely reliable. In the world of microservices, the stable operation of each independent service is related to the overall situation. This is not only about technical implementation, but also about a deep understanding and continuous control of complexity.

When you start to consider this evolution path, what you need is not only tools and code, but also a partner who can deeply understand your business context and implement technical solutions in a solid manner. On this road, robust practices and proven reliability are often more important than a gorgeous technology stack.

Ultimately, all architecture evolutions serve the same goal: to make the system a boost to the business, rather than a drag. Let it run stably, accurately and reliably like the best automation equipment in the workshop, and be able to flexibly adjust and expand when needed. When technology silently supports the operation of business, it may be its greatest value.

Established in 2005,kpowerhas been dedicated to a professional compact motion unit manufacturer, headquartered in Dongguan, Guangdong Province, China. Leveraging innovations in modular drive technology,kpowerintegrates high-performance motors, precision reducers, and multi-protocol control systems to provide efficient and customized smart drive system solutions. Kpower has delivered professional drive system solutions to over 500 enterprise clients globally with products covering various fields such as Smart Home Systems, Automatic Electronics, Robotics, Precision Agriculture, Drones, and Industrial Automation.