Where should the looseness be tightened? Let’s talk about the headaches in microservices

Microservices sound pretty beautiful - each small module performs its own duties and can be flexibly expanded, and everything seems to fall into place. But can it really be used? Sometimes I feel that the more scattered things are, the faster problems will arise.

It's like you have a bunch of exquisite servo motors and servos in your hand. Looking at them individually, each one turns beautifully. But once they are asked to work together and perform a complete set of mechanical movements - hey, some respond half a beat faster, and some signals are lost. The coordination is simply crazy. The same principle applies to microservices: the services are too independent, and the data is blocked; they are too dependent, and the whole system is affected. Where is the balance point between "adhesion" and "coupling"?

Why are your microservices always "fighting"?

You may have encountered this scenario: an order service needs to call user information, check inventory, and notify logistics. The process is not long, but once a certain link gets stuck, the entire link stops. Or more commonly, for a small function change, three or four services must be changed at the same time, which makes the deployment schedule difficult.

This is not just a technical problem, but more like a design "disease". The boundaries between services are blurred, responsibilities are overlapping, and data flows everywhere... We obviously want to use microservices to improve flexibility, but the result is an unclear network.

So someone asked: Should we make the service as "large" as possible and reduce calls? But that would go back to the old path of monolithic architecture. Or, chop the service into smaller pieces? The management costs are rising again.

In fact, the answer is not "big or small", but "how to connect".

A good connection is like a smooth transmission system

Think about it, have you ever assembled a robotic arm? The steering gear is responsible for turning, the motor provides power, and the sensor feedbacks the position - what is the coordination between them? Rather than twisting all the wires together, each unit can be independently calibrated and respond synchronously through clear interface protocols and appropriate signal transmission.

The ideal state between microservices should also be like this. High cohesion means that the internal logic of a service is closely related, like an independent circuit board; low coupling means that the connection between services is simple and clear, just like a plug-in interface, and changing one component does not affect the whole.

How? Instead of relying on hard and fast rules, let’s go back to the source of the problem: Who should be responsible for your business actions?

For example, the operation of "user placing an order": calculating the amount, deducting inventory, and generating logistics orders - if these steps are all crammed into one service, it will be bloated sooner or later. But if we separate "inventory management" and "order processing" and communicate through clear events or messages, then the order service will hardly need to be touched when the inventory service iterates.

This is a "loosely coupled" design: services do not directly call each other's database, do not rely on internal logic, and only "talk" through agreed methods. Even if one party is temporarily down, the other party can continue to work, or at least know how long to wait.

From "how to do" to "how to choose"

The method sounds easy, but you will always encounter specific multiple-choice questions when you implement it. for example:

• To communicate between services, should we use synchronous calls or asynchronous messages?
• Should data be shared or kept separately?
• Where is the appropriate boundary to draw for a function?

In fact, there is no standard answer, only whether it is appropriate or not. Usually, those involving core state changes - such as payment success - may require synchronous confirmation; for logs and notifications that can be delayed, it is easier to use an asynchronous queue. The same is true for data: basic user information that is commonly used and becomes less common can be shared appropriately; but for highly relevant businesses such as order flow, it is best to keep them within their respective services.

The key is not how new the technology is, but how it matches your business rhythm. Just like choosing a motor for a mechanical system, the higher the speed is not the better, but the torque, response, and power consumption must meet the overall needs.

When we talk about microservices, what are we talking about?

After all, microservice architecture is not an end, but a means. It helps you resolve complexity, allows teams to develop in parallel, and allows the system to expand in stages. But its success cannot be separated from an invisible foundation: clear cohesive design and healthy coupling relationship.

This is like a precision platform driven by the Kpower servo system: each motor unit itself is stable and efficient, and at the same time interacts lightly through the control protocol, ultimately achieving smooth and reliable overall operation. You won't see them "fighting" with each other, nor will they be down for maintenance on one unit.

A good microservice architecture pursues exactly this state - independent but not antagonistic; connected but not bundled.

So, before you uninstall your service next time, ask yourself:

• Does this feature change frequently? Is it worth going out on your own?
• Can you control most of the data or logic it relies on?
• Can it communicate with other services using a simple protocol instead of being tightly tied?

Ask these questions clearly, and you may naturally find the balance point: let what should be gathered together, and what should be loosened can be beautifully relaxed.

After all, architectural design is never just a block diagram. It is like injecting a harmonious "soul" into a set of mechanical modules - each unit must be solid on its own, and each unit must have room to breathe. When you can feel the smooth and stable rhythm of collaboration between services, you are probably on the right track.

The rest is to continue to observe and fine-tune. It's like maintaining a mechanical system that you trust. You know why each of its components is here and how they work together. That sense of solidity is itself the most memorable part of technical design.

Established in 2005, Kpower has been dedicated to a professional compact motion unit manufacturer, headquartered in Dongguan, Guangdong Province, China. Leveraging innovations in modular drive technology, Kpower integrates 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.