what is grpc in microservices

The hidden troubles of server system upgrade and the story of a communication protocol

Picture this. In your factory, a robotic arm performs delicate welding tasks. Several servo motors work together seamlessly, and the movements are as smooth as a symphony. Suddenly, a motor slowed down by half a beat - not because of mechanical failure, but because the control instructions were "traffic jammed" at a certain link. The entire production line came to a standstill and coordination turned into chaos. Similar situations are not uncommon in automation projects involving multiple nodes and requiring real-time collaboration.

The root of the problem is often hidden in "communication". If the ways in which servo motors, servos and other mechanical components communicate are not light and clear enough, even the most exquisite design will be compromised.

Is there anything that would make the conversation smarter?

This brings us to the tool we’re going to talk about today: gRPC. It is not a new piece of hardware, but a communication protocol between software. You can think of it as an efficient "secret code" designed between machines. In the world of microservices—that is, the idea of ​​breaking down a large software application into many independent small services—this "code" becomes especially critical.

Why? Because the traditional communication method is sometimes like asking two people to speak in different dialects from a distance, and they have to repeatedly confirm "Is this what you heard?" It's slow and error-prone. The goal of gRPC is to make data exchange between services as direct and fast as internal function calls, and it comes with a clear "protocol specification".

How exactly does it work?

Simply put, gRPC establishes a contract. The developer defined it at the beginning of the design: "Service A will request data from service B in this format, and B will reply in that format." This definition directly determines the data structure of communication between them. When the status data and control commands of the servo system need to flow between different microservices (such as motion planning service, status monitoring service, logic control service) at high speed, this kind of pre-defined, binary format communication is much more efficient than repeatedly parsing and packaging those cumbersome text data (such as common JSON).

What does this mean for machinery and automation projects?

It's speed and real-time. Binary transfers are inherently more compact, and gRPC is based on the HTTP/2 protocol and also allows bidirectional streaming. Imagine your monitoring service could receive a continuous, stream-like stream of real-time status from multiple sensors or motor drives, rather than knocking on the door and asking questions over and over again. This is an underlying advantage for precision control scenarios that require high-frequency feedback.

is a clear interface. The "contract first" model forces teams to think clearly about boundaries when designing communications. This reduces the ambiguity during subsequent integration, allowing modules such as servo control, logic processing, and data acquisition to be connected more cleanly. In the long run, the maintainability of the system will be much stronger.

Then there's language independence. Your motion control service may be written in C++ for ultimate performance, while the upper-level production scheduling service may be written in Go or Python for rapid iteration. gRPC supports multiple programming languages, allowing these services written in different languages ​​​​to communicate seamlessly, bringing freedom to choose technology stacks.

Back to our factory floor

If a microservice architecture integrated with gRPC was behind it, the scene at the beginning might be different. The real-time status of the servo motors of each joint of the robotic arm is continuously reported to the coordination service through streams. Fine-tuning instructions issued by the coordination service can also be delivered accurately with extremely low latency. Communication is no longer a bottleneck and the potential of the system is unleashed.

Of course, there is no silver bullet. The introduction of gRPC means that you have to spend early efforts to define these "contracts" (Protocol Buffers files), which may seem a bit "heavy" for very simple internal communications. But when the systems you face become more and more complex, with more and more nodes, and with higher and higher requirements for response speed and interface clarity, the returns on this investment in the underlying communication layer will gradually appear.

In the many projects involving complex servo and mechanical systems that Kpower has served, we deeply understand that the excellence of hardware requires the wisdom of software to connect it. Choosing the appropriate communication architecture is like choosing the appropriate lubricant and connecting shaft for a precision gear system. It is not often seen, but it determines the smooth and reliable operation of the entire system. Paying attention to the matching and matching of every link from hardware to software is the core of Kpower helping customers to implement their ideas steadily.

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.