When your server system starts to "get awkward": A story about microservices REST API

Have you ever encountered this situation? The three-year-old robotic arm in the workshop suddenly became sluggish one morning. It was still moving, but its response was always half a beat slower, as if it hadn't woken up. The coordination between several servos also began to show slight misalignments. Although it did not affect the overall operation, the accuracy of the processed parts was a bit off.

The problem is often not with the hardware itself

We spent a lot of time checking the motor, sensors, transmission structure - everything was fine. But the problem remains. It was later discovered that the internal communication of the control software behind the scenes started to experience delays. The data exchange between various functional modules is like an old transportation hub, blocked in invisible places.

This is actually a very typical phenomenon. Many mechanical and automation systems run well initially, but as functions increase and the amount of data increases, the efficiency of internal information transmission will quietly decrease. Especially when the system needs to handle multi-axis collaboration, real-time feedback, and dynamic adjustment, traditional monolithic architecture software often becomes a bottleneck.

At this time, you may need to change your mind and look at the problem.

Microservices and REST API: Breaking large systems into small, flexible teams

Imagine if every mechanical unit in the workshop was like a small independent team with tacit understanding. Those responsible for grabbing only focus on grabbing, those responsible for rotating only focus on rotating, and those responsible for positioning focus on positioning. They each have their own "brains" (services), but they communicate with each other at any time using a simple, standard language (REST API).

The most direct benefit of doing so is flexibility. If a certain unit needs to be upgraded or maintained, it will not affect the normal operation of other units. It's like changing a musician in the band and the music can continue. The maintainability of the system is greatly improved.

It's clarity. Each service has clear boundaries of responsibility. When something goes wrong, you know who to go to. When debugging, you can also be more focused and your whole body will not be affected by one thing.

Third, there is scalability. One day you need to add a visual inspection module or connect a new data dashboard, it is like adding a new role to the existing team - just use the same communication language (API) to connect, there is no need to overturn and start over.

But "dismantling" is not the goal, "better collaboration" is

When many people hear "microservices", they think that the more broken the software is, the better. Not really. The basis for splitting should be the natural boundaries of business functions. For mechanical control systems, it may be the core areas of "motion control", "status monitoring", "process logic", and "data persistence".

After splitting, how to let them communicate efficiently and reliably is the key. This is the problem that REST APIs are designed to solve.

Good API design is a bit like developing an efficient communication protocol for the team. it should:

• Intuitive and easy to understand: Seeing the interface address and methods, you can guess what it does. for example/api/motor/statusUsed to obtain motor status,POST /api/taskUsed to issue new tasks.
• Stable and consistent: It behaves the same way today and tomorrow. The format of the returned data and the meaning of the error code remain unified, giving the caller peace of mind.
• Only pass necessary information: No more, no less, just enough to meet the needs of collaboration. Avoid moving large amounts of redundant data between services, which increases network burden and parsing costs.
• Have good "fault tolerance": The network occasionally disconnects and a certain service is temporarily unresponsive. Good API design can help the system degrade gracefully or recover quickly instead of crashing directly.

From concept to practice: some unavoidable specific thoughts

What would we focus on when actually building such a system?

First, the granularity of services. Should the control of each motor be made into an independent service, or should the motion control of an entire axis be used as a service? This requires trade-offs. If it is too detailed, the management complexity will increase; if it is too coarse, the advantages of microservices will be lost. Our experience is to start from core business capabilities and find functional units that are relatively independent and autonomous.

Second, the reliability of communication. In industrial environments, networks are not always perfect. API calls may fail. Therefore, in addition to designing a retry mechanism, sometimes it is also necessary to introduce an asynchronous message queue to prevent important instructions from being lost. Ensuring "delivered at least once" is critical to control instructions.

Third, monitoring and insight. Once the system is taken apart, how do you know if the overall system is healthy? A unified logging, monitoring and link tracking mechanism is required. When a certain workpiece processing times out, you can quickly trace which service (such as the path planning service) is responding slowly, instead of blindly checking all hardware.

Fourth, secure borders. Each service has its own entrance and detailed security policies. Who has access to the motion control interface? Who can only read the status? Role-based API permission management is not optional in industrial systems, but a must.

This is not just a shift in software architecture

Looking at a deeper level, adopting microservices and clear REST API is actually changing the way the system evolves. It makes your automation system like Lego bricks that can be combined, replaced, and upgraded according to business needs. Today you may focus on precision machining, so motion control services are the core; tomorrow you may need to add big data predictive maintenance, then you only need to enhance data collection and analysis services, and the original control flow does not need to be significantly changed.

This kind of flexibility has hidden and huge value for manufacturing environments that require long-term operation and continuous adaptation to new processes and new products. It reduces technical debt and risk for future changes.

existkpower, we are deeply involved in the integrated applications of servo motors, steering gears and various mechanical systems. We've seen too many late-stage bottlenecks caused by software architectural limitations. Precisely because we understand the physical characteristics and control logic of mechanical systems, we pay more attention to building a "strong and flexible" communication skeleton at the software level.

Good technology should not make people feel that it is complicated. Just like a set of excellent microservice REST API, what is ultimately presented to users is a smoother control experience, a more stable production rhythm, and a more leisurely expansion capability. When the equipment in the workshop seems to have a "tacit understanding", there will naturally be fewer problems.

It all starts with a clear design on how to "dialogue".

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.