Bevezetés a gRPC használatába
Élet a SOAP és a REST után
Márk Sági-Kazár
2023-03-22 @ HWSW meetup
whoami
Márk Sági-Kazár
Engineering Technical Lead @ Cisco
Agenda
- About RPC
- RPC vs REST
- Introduction to gRPC
- Implementing a gRPC service
- Advanced features
- When to use gRPC?
- Alternatives
Code samples
About RPC
Definition 🤔
[…] a computer program causes a procedure (subroutine) to execute in a different address space (commonly on another computer on a shared network), which is coded as if it were a normal (local) procedure call, without the programmer explicitly coding the details for the remote interaction
Definition
- in a different address space → someone else’s computer
- normal (local) procedure call → interface
- no details for the remote interaction → implementation
Interface Definition Language
- a language for describing communication
- programming language agnostic
- serves as a contract for RPC APIs
RPC vs REST
| RPC | REST | |
|---|---|---|
| Operates on | procedures (“function calls”) |
resources |
| Underlying protocol | unspecified | primarily HTTP |
| Interactions | protocol encapsulated | HTTP is part of the contract |
- RPC is more suitable for APIs describing actions (vs resources)
- RPC has better type-safety guarantees
- RPC is more strict
- REST may be more performant when operating on large amount of data
RPC example in HTTP
REST example
Introduction to gRPC
About gRPC
- High performance
- Language agnostic (supported languages)
- Uses http/2 transport
- Bi-directional streaming
- Pluggable auth, tracing, load balancing and health checking
IDL: Protocol Buffers
- Interface Definition Language
- Message format (binary serialization)
- Code generation framework
Example 1: Protocol Buffers
Implementing a gRPC service
Example 2: Service definition and server implementation
Example 3: Using the client stub
RPC lifecycle
- Unary RPC
- Server streaming RPC
- Client streaming RPC
- Bidirectional streaming RPC
Example 4: Server streaming RPC
Advanced features
- Authentication
- Metadata
- Error handling
Example 5: Authentication and error handling
Interceptors
- Act as middlewares during the request lifecycle
- Server vs Client
- Unary vs Stream
Example 6: Server unary interceptor
When to use gRPC?
With great power comes great responsibility
- API operates on actions instead of resources
- When efficient communication is a goal
- In polyglot environments
- No need for supporting a wide range of clients
- Internal APIs
whisper microservices
gRPC weaknesses
- Limited web/browser support
- Not human-readable format (more difficult to debug)
- Steeper learning curve
Alternatives
Twirp
Developed at Twitch as a lightweight alternative to gRPC.
https://github.com/twitchtv/twirp
Read the announcement blog post.
Connect
A gRPC-compatible framework with an emphasis on browser- and web-compatibility (from the creators of Buf).
The End
Any questions?
Further reading
- https://grpc.io/
- https://protobuf.dev/
- https://github.com/grpc-ecosystem
Bevezetés a gRPC használatába Élet a SOAP és a REST után Márk Sági-Kazár 2023-03-22 @ HWSW meetup