how to connect microservices

You build a cool robot with movable joints, flexible fingers, and a rotating head. But when you connect all the servo motors and servos to the controller and prepare it to dance - it just freezes in place, or one of its arms waves randomly, and its legs and feet are completely disobedient.

It's not a broken part. The problem is with the connection. The signals are not straightened out and the commands are fighting.

Doesn't this feel similar to putting a bunch of microservices together into a usable system? Each microservice is like a joint and a steering gear on the robot. They work perfectly on their own, but if you just stack them together without clear connections and direction, what you get is a mess of twitches rather than an elegant dance.

So, let’s talk about how to make these “digital joints” really work together.

Why is the connection always a mess?

Imagine that you give ten friends the task of building a boat together. You didn’t tell them how to communicate with each other, who would do it first and who would do it last, you just said, “Let’s get started.” The result may be that someone made two bows, while someone else made three sterns. The materials didn't match, and the time didn't match up. Instead of a boat, what you get is a pile of finger-pointing and a pile of scrap wood.

The same is true in the world of microservices. Each service (e.g. user management, order processing, payment interface) is like your competent friend who needs clear instructions. If the communication channels between them - that is, API calls, message queues, event triggers - are not designed well, the system will become slow, fragile, or even crash. Data can be out of sync between different services, and the failure of one service can knock everything else down like a domino.

This isn't a technical glitch, it's a communication failure.

What is the correct way to connect?

It's not as simple as soldering two servos with a physical wire. This is an agreement, an agreement.

Each service needs to "talk to itself" less and "listen to others" more. This means clearly defined, stable interfaces. For example, when the order service needs user information, it should not directly break into the user service database to search (this is too rude and will also cause tight coupling). It should politely "ask": "Hey, can you give me a copy of user 123's details?" via an explicit API. After the user service hears it, it returns the required data. In this way, they are independent of each other and cooperate seamlessly.

To allow "asynchronous" to happen. Not all requests require immediate response and waiting. Sometimes, service A only needs to "notify" service B: "There is a new order, process it when you are free." Then you can continue to do other things. This is like dropping tasks into a shared inbox (message queue) and letting other services pick up and process them at their own pace. The system as a whole will be more stable, and it will not be blocked just because one link is stuck.

Furthermore, is a "commander" needed? You don’t necessarily need a unique master controller, but you need a “traffic rule” that everyone can understand and follow. A service discovery mechanism (allowing services to find each other), a configuration center (unified management settings), a lightweight gateway (handling some common entry checks, such as authentication) - these are not bosses giving orders, but more like smart traffic light systems coordinating traffic.

Choose a connection solution like a servo motor

When you're picking a servo for a robot, you'll look for torque, speed, accuracy, reliability, as well as whether the size and price match your project. Tools and technologies for connecting microservices also require similar considerations.

Is it reliable? Will the news be lost at every turn? Is it fast? Will latency become a bottleneck? Is it simple? Will it make the system too complex to maintain? Does it scale easily as your "digital robot" grows (and the business grows)?

There is no “standard answer” here that is universally popular. For a small project that is rapidly innovating, it may be enough to use a lightweight HTTP API to directly call it; for a system that processes massive amounts of real-time data, it may require a robust message flow. The key is to understand what the "body" at hand wants to do, and then choose the appropriate "joint connection method" for it.

The moment the system “lives”

When the connection is smooth, magic happens. Imagine your e-commerce application: the user clicks to purchase (triggered by the front-end service), the order service creates a record (and sends a reservation request to the inventory service), the payment service is called, after completion, the logistics service is triggered to prepare for shipment, and the email notification service sends a confirmation letter to the user. This series of movements is like a complex set of boxing techniques, executed smoothly and automatically.

All the user sees is a simple "Purchase Successful" page. He couldn't see how the dozen microservices behind him were like precise clock gears, transmitting power and information through elegant connections. This invisibility is the highest state of good connection.

So, where to start?

Start by acknowledging that “connectivity is a big problem.” However, don't try to connect all services in the most complicated way at once. Choose a core business process, such as "user registration", and try to make it run with clearly defined interfaces and asynchronous messages. Observe, debug, and feel the rhythm of data flow.

You'll find that when each part works independently but also in harmony, what you build is no longer a bunch of code, but a living organism. It can adapt, it can grow, and it can complete unexpectedly complex tasks.

It's like you finally adjusted the parameters and signal sequences of all the servos of that robot and pressed the start button - it no longer twitched, but took a steady step forward, then turned to you and nodded.

At that moment, all the connecting work was worth it.

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.kpowerhas 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.