Exploring GraphQL, gRPC, and REST APIs in Cloud-Native Development

Cloud-native development is a modern approach to building and deploying applications leveraging the advantages of the cloud computing model. These applications are designed to be scalable, resilient, and adaptable to changing business needs and customer expectations. One of the key aspects of cloud-native development is how applications interact with data and functionality provided by the interacting services and interfacing systems. This is where APIs (Application Programming Interfaces) come in; which define the contracts, inputs, outputs, and behaviors of the services or resources of the systems. However, not all APIs are created equally as their complexity and applicability vary widely. There are different styles and paradigms of designing and implementing APIs, each with strengths and weaknesses.

Following are the three most popular and widely used API styles in the world of cloud-native development...??

1. REST (Representational State Transfer): REST emerged as a set of architectural principles for designing networked applications. It gained prominence through Roy Fielding’s doctoral dissertation in 2000. REST aims to provide a standard way for clients and servers to communicate over the web. It emphasizes statelessness, uniform resource identifiers (URIs), and standard HTTP methods (GET, POST, PUT, DELETE) for data manipulation. RESTful APIs are widely used for web services and mobile applications.
2. GraphQL (Graph Query Language): GraphQL was developed by Facebook in 2012 and later open-sourced in 2015. Facebook introduced GraphQL to address issues related to over-fetching data in REST APIs. Unlike REST, which relies on predefined endpoints, GraphQL allows clients to request specific data they need. It provides a flexible schema-based approach, enabling efficient data loading and real-time updates through subscriptions. GraphQL is especially useful for complex data structures, such as social graphs. It is now used by many companies, such as GitHub, Netflix, Shopify, Airbnb, etc. According to GitHub's 2020 State of the Octoverse report, the use of GraphQL saw a 5X increase in usage over the past three years.
3. gRPC (Remote Procedure Calls): gRPC was developed by Google and first released publicly in 2015. Google created gRPC as an efficient and extensible framework for building APIs. It uses Protocol Buffers (protobufs) for serialization and supports bidirectional streaming, authentication, and load balancing. gRPC is commonly used for microservices communication within large-scale systems.

Comparing GraphQL, gRPC, and REST APIs

Let's look in detail at the specialty of these APIs...

??Data Query / Fetching Flexibility:?

GraphQL empowers clients to request precisely the data they need. No more over-fetching or under-fetching! With a single query, you can seamlessly retrieve user profiles and their recent posts, streamlining the data-fetching process. On the other hand, REST APIs often entail predefined responses, potentially leading to either data wastage or multiple requests for related data.

?gRPC is the modern high-performance remote procedure call (gRPC) framework that offers data retrieval using HTTP/2 and protobuf; more like a contract-first approach with protobuf service definitions. gRPC supports bidirectional streaming and long-lived connections.?

With GraphQL, multiple data points can be packed into a single query. This reduces the need for numerous requests, enhancing performance and efficiency. GraphQL responses are defined by the client's query, avoiding overloading with unnecessary data; whereas REST responses are predefined by the server, possibly containing extraneous data. GraphQL supports strongly typed schema and runtime type checking.

REST APIs, while being reliable, might necessitate multiple requests to different endpoints for cohesive data. REST follows the architectural style for building scalable web APIs using HTTP requests. Resources are accessed via predictable URLs and HTTP methods like GET, POST, PUT, and DELETE.

?Statelessness and Versioning:

Both GraphQL and gRPC are well-suited for stateless implementations. GraphQL is stateless by default. Queries contain all the information needed to fulfill the request. The gRPC protocol itself does not require a state. gRPC can be stateless if service implementations avoid keeping the state between calls.?

GraphQL provides a more flexible approach to versioning as clients can request specific fields. The versioning can be handled through their strongly typed schemas and service definitions. gRPC uses protobuf service definitions which enable versioning. Changing a service requires a new proto file. Clients specify a protobuf version in requests. GraphQL and gRPC type of safety enable effective caching strategies.?

REST APIs are completely stateless. REST requires versioning through different endpoints or query parameters.?

?? Caching and Performance:

Both GraphQL and gRPC have some differences when it comes to caching and versioning. GraphQL allows retrieving multiple resources in a single request, avoiding over and under-fetching issues common in REST.

GraphQL can still be challenging due to dynamic queries. GraphQL caching is possible by caching the results of common queries. Client apps can manage an in-memory cache. CDNs and server caching can also be used.

However, gRPC encourages caching by default through HTTP/2 header support. gRPC responses have cache control headers for client and server-side caching. gRPC is typically faster and more efficient than REST.

REST API allows for easier caching with standardized endpoints. REST API optimization techniques, such as caching and content delivery networks, are crucial for enhancing overall performance.

Relevance to Cloud-Native Development:

In the dynamic landscape of cloud-native development, all three API frameworks - GraphQL, gRPC, and REST APIs have their places. In microservices architectures, GraphQL shines for front-end teams seeking tailored data. gRPC are useful for internal microservices, and point-to-point real-time services. Meanwhile, REST APIs are well-suited for clearly defined microservices, often managed by backend teams. Leading hyperscale cloud providers like AWS, Azure, and Google Cloud recognize the importance of offering options.

Example: Imagine a social media app where users have profiles and posts. GraphQL allows a single query to fetch both a user's profile and their recent posts, optimizing data retrieval. In contrast, REST APIs might require separate requests, potentially resulting in slower data retrieval for end-users. But, if there were some kind of real-time bidirectional streaming services requirements with long-lived connections; gRPC could be the savior for developers.

How to choose among GraphQL, gRPC, and REST API?

REST and GraphQL are both valid and powerful options for designing and implementing APIs, but they have different trade-offs and implications. There is no definitive answer to which one is better or worse, as it depends on various factors such as the complexity of the data model, the diversity of the clients, the frequency of changes, etc. However, below are some general guidelines that can help you make an informed decision:

Use REST, when it’s about following a simple and standardized approach that is widely supported and understood by most developers and tools.

• REST is simple and scalable for cloud services and serverless functions.
• REST is suitable for scenarios where there is a clear and stable definition of resources and their representations, and where HTTP features such as caching, compression, etc. can be leveraged.
• REST is also easier to implement on the server side, which allows existing frameworks and libraries to handle most of the common tasks.
• Loose coupling between client and server; keeps requests stateless, and cacheable; but simple and lightweight. Which is useful for distributed architectures, public APIs, and web services.

Use GraphQL, to have more control and flexibility over what data you send and receive from the server.

• GraphQL flexibility suits the agile nature of cloud-native development.
• GraphQL is suitable for scenarios where you have a complex and dynamic data model, and where you need to support different types of clients with different needs and preferences.
• GraphQL is also more efficient in terms of performance and bandwidth usage, as you can avoid unnecessary data transfer and requests.
• GraphQL requires more effort and expertise on both the client and the server side, as you need to define your schema, write your queries and mutations, and implement your resolvers.
• Useful when you need flexible queries and granular data access. Common in web and mobile apps.

Use gRPC, for real-time bidirectional streaming services requirements with long-lived connections.

• gRPC efficient performance suits microservices architectures on the cloud.
• ?gRPC requires a contract-first approach with protobuf service definitions.

In the exciting journey of cloud-native development, the choices among gRPC, GraphQL, and REST API hinge on factors like performance data complexity, client requirements, and architectural considerations. All the API frameworks contribute to building robust, efficient, and scalable applications in our interconnected digital landscape.

Summary:

In cloud-native development, all API styles are relevant and applicable per their specific context. Leveraging the specialized characteristics helps define architecture to be optimally efficient and performant. GraphQL is query-focused, REST is resource-focused, and gRPC is service-focused. GraphQL has a strongly typed schema, REST is untyped, and gRPC is strongly typed via protobuf definitions. GraphQL uses a single endpoint, REST exposes structured endpoints and RPC has one endpoint per service. GraphQL and REST are typically used over HTTP, and gRPC uses HTTP/2. GraphQL offers more flexible data fetching, REST provides simple scalable APIs, and gRPC enables high-performance service communication. The choice depends on specific architectural needs and tradeoffs. All three can have a role in cloud-native development

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?? References:

1. State of GraphQL 2022 Report Summary and Insights (hasura.io)
2. GraphQL vs REST API - Difference Between API Design Architectures - AWS (amazon.com)
3. GraphQL vs REST - A comparison (howtographql.com)
4. Interacting with APIs: REST and GraphQL | Google Cloud Blog