The RPC pattern started being used around the 80s, but this doesn’t automatically make it obsolete. So, instead of editing the existing ones, we create new ones ending up with a huge list of overlapping functions that are hard to understand. In RPC there’s no way to introspect the API or send a request and start understanding what function to call based on its requests.įunction explosion. So, the client either worries about any possible side effects of calling a particular endpoint or tries figuring out what endpoint to call because it doesn’t understand how the server is naming its functions. An RPC’s tight coupling makes scalability requirements and loosely coupled teams hard to achieve. This raises security issues as it’s quite easy to leak implementation details about the underlying system into the API.

RPC’s tight coupling to the underlying system doesn’t allow for an abstraction layer between the functions in the system and the external API. The tighter it is to the underlying system, the less reusable it will be for other systems. An API’s abstraction level contributes to its reusability. RPC is able to optimize the network layer and make it very efficient with sending tons of messages per day between different services. Lightweight payloads go easy on the network providing high performance, which is important for shared servers and for parallel computations executing on networks of workstations. If we get a new requirement for our API, we can easily add another endpoint executing this requirement: 1) Write a new function and throw it behind an endpoint and 2) now a client can hit this endpoint and get the info meeting the set requirement. The mechanics of the interaction between a server and a client come down to calling an endpoint and getting a response.Įasy-to-add functions. RPC uses GET to fetch information and POST for everything else. Remote Procedure Calling Mechanism, Source: Guru99 RPC Pros

The server stub and client stub take care of the serialization and deserialization of the parameters. On receiving the message, the server deserializes its content, executes the requested operation, and sends a result back to the client. How RPC worksĪ client invokes a remote procedure, serializes the parameters and additional information into a message, and sends the message to a server. With pluggable support for load balancing, tracing, health checking, and authentication, gRPC is well-suited for connecting microservices. gRPC is the latest RPC version developed by Google in 2015. So, later an RPC API started using a more concrete JSON-RPC specification which is considered a simpler alternative to SOAP. Initial XML-RPC was problematic because ensuring data types of XML payloads is tough. RPC extends the notion of local procedure calling but puts it in the context of an HTTP API. In this article, we’ll stay objective and discuss the four major API styles in the order of their appearance, compare their strong and weak sides, and highlight the scenarios where each of them fits best.įour major API styles compared Remote Procedure Call (RPC): invoking a function on another systemĪ Remote Procedure Call is a specification that allows for remote execution of a function in a different context. The problem with these opinions is that they are one-sided picking a technology itself instead of considering how its actual properties and characteristics match the situation at hand.Ĭheck our video if you prefer watching to reading Today, many API consumers refer to REST as “ REST in peace” and cheer for GraphQL, while ten years ago it was a reverse story with REST as the winner to replace SOAP. A pull of choices raises endless debates as to which architectural style is best.ĪPI styles over time, Source: Rob Crowley Each of them has its own patterns of standardizing data exchange. Over time, different API architectural styles have been released. These specifications make up the API architecture. In order to integrate applications quickly and at scale, APIs are realized using protocols and/or specifications to define the semantics and syntax of the messages passed across the wire. So, developers often build bridges – Application Programming Interfaces – to allow one system to access the information or functionality of another. Two separate applications need an intermediary to talk to each other.

Which API pattern fits your use case best? Reading time: 11 minutes.

Representational state transfer (REST): making data available as resources.

Simple Objects Access Protocol (SOAP): making data available as services.

Remote Procedure Call (RPC): invoking a function on another system.

Soap vs rest vs microservices