gRPC vs GraphQL

Besides GraphQL and REST, there are other API technologies available, one of which is gRPC. gRPC is an open-source Remote Procedure Call framework that allows you to create APIs. In this guide, we will explore the distinctions and comparisons between gRPC and GraphQL.

What is GraphQL?

GraphQL is a query language specifically designed for querying graph-shaped data, hence the name GraphQL. Although it shares the "QL" suffix with SQL, GraphQL is fundamentally a different language. It is not inherently tied to NoSQL databases, even though GraphQL can be used with NoSQL databases as the underlying storage. It can also work with SQL databases or any other storage method, such as text files or in-memory storage.

What is gRPC?

gRPC is an open-source framework built on top of RPC, with a focus on HTTP/2. It inherits HTTP/2's advantages like binary framing, multiplexing, server push, and header compression, making it highly efficient for server communication.

As depicted in the diagram, when using gRPC for remote service invocation, the client only needs a gRPC stub. It sends Proto Requests to the gRPC server and receives the invocation results through Proto Responses from the server.

Comparison Between gRPC vs GraphQL

The following table compares the features of gRPC and GraphQL:

Feature	gRPC	GraphQL
Message Format	Binary format, smaller size, faster serialization, harder to inspect	JSON format, larger size, explicit structure, easier to inspect
Request Format	One method call at a time, may require multiple calls for more data, may cause underfetching	Fetches multiple resources in a single request, reduces round trips
Default Values	No default values included, smaller message size	Allows setting default values for parameters but not for requested fields
Forward Compatibility	Good forward compatibility, existing clients can communicate with updated servers using the same code	Good forward compatibility, existing clients can communicate with updated servers using GraphQL mechanisms

Message Format

gRPC and GraphQL differ in their message format. gRPC uses a binary format for data transmission, resulting in smaller message size and faster serialization and parsing. However, it is harder to debug and inspect than JSON. GraphQL transmits data in JSON format, which has a more explicit information structure, but larger message size. The choice between the two may depend on the specific requirements of the application being developed.

Default Values:

When it comes to default values, gRPC and GraphQL have different approaches. gRPC messages do not include default values, which results in a smaller message size. In contrast, GraphQL allows setting default values for parameters, but not for requested fields. This means that while gRPC messages may be more compact, GraphQL provides more flexibility in terms of default values.

Request Format

In gRPC, we make one method call at a time. If we need more data than what a single method returns, we have to make multiple method calls. If we require the response data from the first method call to determine the next method to call, it results in consecutive round trips. This can cause significant latency unless the client and server are in the same data center. This issue is known as underfetching, where the returned data from a request is insufficient, leading to the need for multiple requests to retrieve the required data.

Forward Compatibility

Both gRPC and GraphQL have good forward compatibility. This means that existing clients can be updated to communicate with updated servers using their respective mechanisms.

gRPC Benefits

gRPC offers significant benefits, including efficient data exchange through Proto bufo's binary serialization, support for HTTP/2 multiplexing, various streaming types (server, client, and bidirectional), unary interactions, and automated code generation for 11 programming languages. These advantages make gRPC an attractive choice for building high-performance and scalable distributed systems.

The Pros and Cons of gRPC

gRPC has several advantages and disadvantages:

Advantage of gRPC

Uses a binary format for data transmission, resulting in smaller message size and faster serialization and parsing.
Supports multiple languages and platforms, making it easier to develop and maintain cross-platform applications.
Provides good forward compatibility, allowing existing clients to communicate with updated servers using the same client-side code.
Offers built-in support for load balancing, service discovery, and authentication, making it easier to manage and secure microservices architectures.
Supports both unary and streaming requests and responses, allowing for more flexible communication patterns.

Drawback of gRPC

Requires developers to define the API using protocol buffers, which can be challenging for those who are not familiar with the format.
May require more work to set up compared to REST APIs, as it requires generating client and server code from the protocol buffer definitions.
This may lead to underfetching if the client does not request all the necessary data, leading to additional round trips and increased latency.
May not be suitable for all use cases, as it is optimized for high-performance, low-latency communication between microservices.

The Pros and Cons of GraphQL

GraphQL has several advantages and disadvantages:

Advantage of GraphQL

Allows fetching multiple resources in a single request, reducing the number of round trips and improving performance.
Retrieves only the required data, reducing overfetching and saving bandwidth.
Provides a single endpoint for fetching all resources, simplifying the API and making it easier to manage.
Allows clients to specify the shape and structure of the data they need, making it easier to develop and maintain client applications.
Supports real-time updates through subscriptions, allowing clients to receive updates in real-time without needing to poll the server.

Drawback of GraphQL

Requires a learning curve for developers who are used to REST APIs.
Can be more complex to implement on the server side compared to REST APIs.
May lead to underfetching if the client does not request all the necessary data, leading to additional round trips and increased latency.
Can be less secure if not implemented properly, as it allows clients to specify the data they need, potentially exposing sensitive information.

GraphQL in Apidog

Apidog is a tool that supports GraphQL, allowing you to test and debug GraphQL APIs to ensure they're working as expected. Similar to Postman's GraphQL feature, Apidog allows you to easily manage and test your GraphQL APIs. We're constantly working to improve Apidog with more automation features to make testing and managing your APIs even easier. Thank you for choosing Apidog for your GraphQL needs!