gRPC (acronym for gRPC Remote Procedure Calls) is a

cross-platform Within computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several Computing platform, computing platforms. Some ...

high-performance

remote procedure call In distributed computing, a remote procedure call (RPC) is when a computer program causes a procedure (subroutine) to execute in a different address space (commonly on another computer on a shared computer network), which is written as if it were a ...

(RPC) framework. gRPC was initially created by

Google Google LLC (, ) is an American multinational corporation and technology company focusing on online advertising, search engine technology, cloud computing, computer software, quantum computing, e-commerce, consumer electronics, and artificial ...

, but is

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...

and is used in many organizations. Use cases range from microservices to the "last mile" of computing (mobile, web, and Internet of Things). gRPC uses

HTTP/2 HTTP/2 (originally named HTTP/2.0) is a major revision of the HTTP network protocol used by the World Wide Web. It was derived from the earlier experimental SPDY protocol, originally developed by Google. HTTP/2 was developed by the HTTP Working ...

for transport,

Protocol Buffers Protocol Buffers (Protobuf) is a free and open-source cross-platform data format used to serialize structured data. It is useful in developing programs that communicate with each other over a network or for storing data. The method involves an ...

as the

interface description language An interface description language or interface definition language (IDL) is a generic term for a language that lets a program or object written in one language communicate with another program written in an unknown language. IDLs are usually use ...

, and provides features such as authentication, bidirectional streaming and flow control, blocking or nonblocking bindings, and cancellation and timeouts. It generates cross-platform client and server bindings for many languages. The most common usage scenarios include connecting services in a microservices style architecture, or connecting mobile device clients to backend services. As of 2019, gRPC's use of HTTP/2 makes it impossible to implement a gRPC client in a browser, instead requiring a proxy.

History

From about 2001, Google created a general-purpose RPC infrastructure called Stubby to connect the large number of

microservices In software engineering, a microservice architecture is an architectural pattern that organizes an application into a collection of loosely coupled, fine-grained services that communicate through lightweight protocols. This pattern is characterize ...

running within and across its

data centers A data center is a building, a dedicated space within a building, or a group of buildings used to house computer, computer systems and associated components, such as telecommunications and computer data storage, storage systems. Since IT opera ...

. In March 2015, Google decided to build the next version of Stubby and make it open source. The result was gRPC.

Authentication

gRPC supports the usage of

Transport Layer Security Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network, such as the Internet. The protocol is widely used in applications such as email, instant messaging, and voice over ...

(TLS) and token-based authentication. Connection to Google services must use TLS. There are two types of credentials: channel credentials and call credentials. For token-based authorization, gRPC provides Server Interceptor and a Client Interceptor.

Encoding

gRPC uses

to encode data. Protocol buffers provide a serialization format and an Interface Definition Language.

Testing

Some of the software tools used for testing gRPC implementations include

Postman A mail carrier, also referred to as a mailman, mailwoman, mailperson, postal carrier, postman, postwoman, postperson, person of post, letter carrier (in American English), or colloquially postie (in Australia, Canada, New Zealand, and the Unite ...

, ezy, Insomnia, and Step CI.

Adoption

Many organizations use gRPC, including

Uber Uber Technologies, Inc. is an American multinational transportation company that provides Ridesharing company, ride-hailing services, courier services, food delivery, and freight transport. It is headquartered in San Francisco, California, a ...

Square In geometry, a square is a regular polygon, regular quadrilateral. It has four straight sides of equal length and four equal angles. Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal si ...

Netflix Netflix is an American subscription video on-demand over-the-top streaming service. The service primarily distributes original and acquired films and television shows from various genres, and it is available internationally in multiple lang ...

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

CoreOS Container Linux (formerly CoreOS Linux) is a discontinued open-source lightweight operating system based on the Linux kernel and designed for providing infrastructure for clustered deployments. One of its focuses was scalability. As an operati ...

, Docker,

CockroachDB CockroachDB is a source-available distributed SQL database management system developed by Cockroach Labs. The relational functionality is built on top of a distributed, transactional, consistent key-value store that can survive a variety of d ...

Arista Networks Arista Networks, Inc. (formerly Arastra) is an American computer networking company headquartered in Santa Clara, California. The company designs and sells Multilayer switch, multilayer network switches to deliver software-defined networking (SDN) ...

Cisco Cisco Systems, Inc. (using the trademark Cisco) is an American multinational digital communications technology conglomerate corporation headquartered in San Jose, California. Cisco develops, manufactures, and sells networking hardware, s ...

Juniper Networks Juniper Networks, Inc. is an American multinational corporation headquartered in Sunnyvale, California. The company develops and markets networking products, including Router (computing), routers, Network switch, switches, network management so ...

Spotify Spotify (; ) is a List of companies of Sweden, Swedish Music streaming service, audio streaming and media service provider founded on 23 April 2006 by Daniel Ek and Martin Lorentzon. , it is one of the largest providers of music streaming services ...

Zalando Zalando SE is a publicly traded international online retailer based in Berlin which is active across Europe and specializes in shoes, fashion and beauty products. The company was founded in 2008 by David Schneider and Robert Gentz and has more th ...

Dropbox Dropbox is a file hosting service operated by the American company Dropbox, Inc., headquartered in San Francisco, California, that offers cloud storage, file synchronization, personal cloud, and Client (computing), client software. Dropbox w ...

, and Google as the original developer. The open source project u-bmc uses gRPC to replace

Intelligent Platform Management Interface The Intelligent Platform Management Interface (IPMI) is a set of Interface (computing), computer interface specifications for an autonomous computer subsystem that provides management and monitoring capabilities independently of the host system's C ...

(IPMI). On 8 January 2019,

announced that the next version of "Courier", their RPC framework at the core of their

service-oriented architecture In software engineering, service-oriented architecture (SOA) is an architectural style that focuses on discrete services instead of a monolithic design. SOA is a good choice for system integration. By consequence, it is also applied in the field ...

(SOA), would be migrated to be based on gRPC, primarily because it aligned well with their existing custom RPC frameworks.

Alternatives

Cap'n Proto Cap’n Proto is a Serialization, data serialization format and Remote procedure call, Remote Procedure Call (RPC) framework for exchanging data between computer programs. The high-level design focuses on speed and security, making it suitable f ...

Apache Thrift Thrift is an IDL (interface definition language, Interface Definition Language) and Binary protocol, binary communication protocol used for defining and creating service (systems architecture), services for programming languages. It was developed ...

Apache Avro Avro is a row-oriented remote procedure call and data serialization framework developed within Apache's Hadoop project. It uses JSON for defining data types and protocols, and serializes data in a ...

JSON-RPC JSON-RPC (JavaScript Object Notation-Remote Procedure Call) is a JSON-based wire protocol for remote procedure calls (RPC). It is similar to the XML-RPC protocol, defining only a few data types and commands. JSON-RPC allows for notifications (data ...

XML-RPC XML-RPC is a remote procedure call (RPC) protocol which uses XML to encode its calls and HTTP as a transport mechanism.Simon St. Laurent, Joe Johnston, Edd Dumbill. (June 2001) ''Programming Web Services with XML-RPC.'' O'Reilly. First Edition. ...

References

External links

gRPC Home PagegRPC – github.comgRPC – opensource.google.com
{{Google FOSS Remote procedure call Software using the Apache license Google software Free software programmed in C++ Free software programmed in Python