When developers first learn gRPC, they usually focus on getting their first remote call working. They create a channel, create a stub, send a request, receive a response, and feel satisfied that the system works. While this is a great starting point, real-world applications require a deeper understanding of how these components should be managed over time.

A production-ready system is not only about making a call work once, but about designing communication in a way that is efficient, scalable, and reliable under continuous usage.

In this tutorial, we will carefully examine how channels and stubs should be created, reused, and managed in real applications, and why the naive “create every time” approach is not suitable beyond demos.

Revisiting What We Did Earlier

In the earlier lecture, we created:

• A channel, which represents the connection to the remote server
• A stub, which acts as the client-side proxy to call the remote service
• A request object that was sent to the server
• A response received from the server

The entire process looked simple and straightforward, and that simplicity is one of the reasons gRPC is loved by developers.

However, once developers see how easy it is, they naturally begin to wonder about lifecycle management. They start asking questions such as whether a new channel should be created for each request, or whether a stub should be recreated repeatedly across different classes.

These questions are important because wrong lifecycle decisions can silently hurt performance.

Understanding the Purpose of a Channel

A gRPC channel is not just a simple object that forwards a request. It is a managed communication layer that knows how to establish and maintain connectivity with a remote server.

When you create a channel, you are giving gRPC the server’s location, such as localhost:6565, and from that point onward the framework takes responsibility for managing the communication path.

A channel is designed to be long-lived because it internally manages connections, reconnections, and resource usage in a smart and optimized manner.

This means the developer does not need to micromanage sockets or retry logic.

Should a Channel Be Created for Every Request?

This is one of the most common beginner doubts.

The short and correct answer is no, but the reasoning is more important than the answer itself.

Creating a channel is not a trivial operation. It may involve establishing TCP connections, performing negotiation steps, and allocating internal resources. If this process is repeated for every single request, the application will waste time and system resources.

A channel is meant to be created once when the application starts and then reused for many remote calls.

This design is very similar to how database connections or HTTP client pools are handled in modern applications. You do not open a new database connection for every SQL query, and similarly you do not open a new gRPC channel for every RPC call.

What If the Server Restarts or Crashes?

Developers sometimes worry that a long-lived channel may become invalid if the server goes down temporarily.

This concern is understandable, but gRPC already anticipates such scenarios.

If the server restarts or becomes temporarily unavailable, gRPC can handle reconnection attempts internally. The channel does not immediately become useless. Instead, it keeps trying to re-establish communication when possible.

The only real requirement is that when a request is sent, the server must be running to process it, which is a universal rule for all network-based systems and not something unique to gRPC.

The same expectation exists for REST APIs, databases, and messaging systems.

Creating and Reusing the Stub

Once a channel exists, the stub is created using that channel. The stub represents the remote service and exposes methods that look like local Java methods.

A beginner might assume that stubs must also be recreated frequently, but this is not necessary.

A stub is designed to be reused and can safely live for the lifetime of the application.

In real systems, a stub is often treated like a singleton dependency that is injected wherever needed, just like a Spring bean.

Thread Safety of Stubs

Concurrency is a serious concern in modern applications where multiple threads may perform remote calls simultaneously.

Fortunately, gRPC stubs are thread-safe.

This means multiple classes and multiple threads can use the same stub instance without corrupting state or causing race conditions. This makes the stub ideal for shared usage across the application.

For example, if several services in your system need to talk to the Bank Service, they can all share the same stub instance without any special synchronization logic.

Naming Matters in Real Projects

In learning examples, developers often name the variable simply as stub. While this is acceptable in a playground project, it is not good practice in a real codebase.

A meaningful name like bankServiceClient or bankServiceStub makes the code self-explanatory and improves readability. When someone reads bankServiceClient.getAccountBalance(), the intent is immediately clear.

Readable code reduces cognitive load and improves long-term maintainability, especially in large systems.