REST IS GREAT

Tens of millions of APIs built on REST
Easy to understand (Text-based protocol)
A plethora of great tools for testing and inspecting
High-quality implementation of HTTP available

...but it has problems

ALLOW ME TO ILLUSTRATE THEM TO YOU

0

Advanced issue found

▲

...using some work conversations

SO, IS THERE A SOLUTION?

YES

...and it is a pretty solid attempt to fix all these things

SAY HI TO

gRPC

A high-performance, open-source universal RPC framework

So what's so great about this gRPC thingy anyway?

Built by Google
Based on HTTP/2
Uses protocol buffers for serialization
- Binary format
- More compact than JSON and other text-formats
- Type-safe
Layered and pluggable (monitoring, auth, etc)

gRPC IDL

INTERFACE DEFINITION LANGUAGE

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Advanced issue found

▲

 syntax = "proto3";
package helloworld;
 
// The greeter service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}
 
// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}
 
// The response message containing the greetings
message HelloReply {
  string message = 1;
}

RUN THE COMPILER

PROTOC

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Advanced issue found

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 protoc --go_out=. --go-grpc_out=. --go_opt=paths=source_relative --go-grpc_opt=paths=source_relative helloworld/helloworld.proto

 protoc --plugin=protoc-gen-grpc-java --grpc-java_out="$OUTPUT_FILE" --proto_path="$DIR_OF_PROTO_FILE" helloworld/helloworld.proto

 protoc --plugin=protoc-gen-grpc-python --grpc-python_out="$OUTPUT_FILE" --proto_path="$DIR_OF_PROTO_FILE" helloworld/helloworld.proto

HERE'S THE MAGIC!

GENERATED CLIENT SIDE CODE

 public static final class GreeterBlockingStub extends AbstractBlockingStub<GreeterBlockingStub> {
 
    private GreeterBlockingStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
      super(channel, callOptions);
    }
 
    @java.lang.Override
    protected GreeterBlockingStub build(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
      return new GreeterBlockingStub(channel, callOptions);
    }
 
    /**
     * Sends a greeting
     */
    public io.grpc.examples.helloworld.HelloReply sayHello(HelloRequest request) {
      return blockingUnaryCall(
      getChannel(), getSayHelloMethod(), getCallOptions(), request);
    }
}

HERE'S THE MAGIC!

GENERATED SERVER SIDE STUB

 public static abstract class GreeterImplBase implements io.grpc.BindableService {
 
    /**
     * Sends a greeting
     */
    public void sayHello(HelloRequest request, StreamObserver<HelloReply> responseObserver) {
      asyncUnimplementedUnaryCall(getSayHelloMethod(), responseObserver);
    }
 
    @java.lang.Override 
    public final io.grpc.ServerServiceDefinition bindService() {
      return io.grpc.ServerServiceDefinition.builder(getServiceDescriptor())
          .addMethod(
            getSayHelloMethod(),
            asyncUnaryCall(
              new MethodHandlers<
                io.grpc.examples.helloworld.HelloRequest,
                io.grpc.examples.helloworld.HelloReply>(
                  this, METHODID_SAY_HELLO)))
          .build();
    }
}

gRPC SUPPORTED LANGUAGES

For generating clients

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Advanced issue found

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Android Java
C# / .NET
C++
Dart
Go
Java

Kotlin / JVM
Node.js
Objective-C
PHP
Python
Ruby

C++
Java
Go
Python
Node.js
Ruby
C#

gRPC SUPPORTED LANGUAGES

For generating server stubs

PERFORMANCE

https://nilsmagnus.github.io/post/proto-json-sizes/

 // Sample response body
{
  "query": "myQuery",
  "page_number": 42,
  "result_per_page": 100,
  "tickers": [
    {
      "name": "rPs",
      "value": 9.768923
    },
    {
      "name": "WEo",
      "value": 6.067048
    }
  ]
}

MESSAGE SIZE (in bytes)

PERFORMANCE

MESSAGE SIZE (in bytes)

https://nilsmagnus.github.io/post/proto-json-sizes/

no of tickers	size raw JSON	size protobuf
0	58	13
1	102	25
2	133	37
10	396	133
20	724	253
200	6578	2413
2000	65250	24013

PERFORMANCE

MESSAGE SIZE (in bytes)

https://nilsmagnus.github.io/post/proto-json-sizes/

no of tickers	size gzipped JSON	size gzipped protobuf
0	82	42
1	125	54
2	142	64
10	235	127
20	331	230
200	1970	1629
2000	17539	14808

OTHER SUPPORTED PRODUCTION LEVEL FEATURES

Timeouts, cancellation
Middleware (Authentication, Metrics)
Server-side streaming
Bi-directional streaming

THE BAD & THE UGLY

Load balancing is available but immature
Being a new ecosystem, tooling support is still growing
- curl is not available
Documentation is still under development
Error handling is not that great
- Cannot send error response bodies (HTML pages)
- No standardized set of error codes; onus on the server to define the error codes
Browser support is limited

Where should we use or not use gRPC?

Full-fledged browser support is not available
- But if our frontends are built on the BFF framework, we can continue using REST for frontend-to-server communication and use gRPC to communicate between services
gRPC is a very good fit for communication between microservices inside a closed network

Who is using gRPC in production?

Almost all of Google has transitioned to gRPC
- Internally known as stubby
Netflix
Cisco
Cockroach Labs
Twilio

REFERENCES AND FURTHER READING

https://code.tutsplus.com/tutorials/rest-vs-grpc-battle-of-the-apis--cms-30711
https://www.youtube.com/watch?v=ZmGyeseXz8M
https://grpc.io/docs/languages/java/quickstart/
https://medium.com/@EmperorRXF/evaluating-performance-of-rest-vs-grpc-1b8bdf0b22da
https://nilsmagnus.github.io/post/proto-json-sizes/
https://www.youtube.com/watch?v=RoXT_Rkg8LA

We
Shouldn't
Make REST APIs

REST IS GREAT

ALLOW ME TO ILLUSTRATE THEM TO YOU

PROBLEM

Not all operations are intuitively and sufficiently modeled by the REST paradigm

In the above example, what will the REST verb be for the restart endpoint?

PROBLEM

PROBLEM

PROBLEM

PROBLEM

SO, IS THERE A SOLUTION?

YES

SAY HI TO

gRPC

So what's so great about this gRPC thingy anyway?

gRPC IDL

RUN THE COMPILER

HERE'S THE MAGIC!

HERE'S THE MAGIC!

gRPC SUPPORTED LANGUAGES

gRPC SUPPORTED LANGUAGES

PERFORMANCE

PERFORMANCE

PERFORMANCE

OTHER SUPPORTED PRODUCTION LEVEL FEATURES

THE BAD & THE UGLY

Where should we use or not use gRPC?

Who is using gRPC in production?

REFERENCES AND FURTHER READING

Thank
You.

	syntax = "proto3";
	package helloworld;

	// The greeter service definition.
	service Greeter {
	// Sends a greeting
	rpc SayHello (HelloRequest) returns (HelloReply) {}
	}

	// The request message containing the user's name.
	message HelloRequest {
	string name = 1;
	}

	// The response message containing the greetings
	message HelloReply {
	string message = 1;
	}

	public static final class GreeterBlockingStub extends AbstractBlockingStub<GreeterBlockingStub> {

	private GreeterBlockingStub(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
	super(channel, callOptions);
	}

	@java.lang.Override
	protected GreeterBlockingStub build(io.grpc.Channel channel, io.grpc.CallOptions callOptions) {
	return new GreeterBlockingStub(channel, callOptions);
	}

	/**
	* Sends a greeting
	*/
	public io.grpc.examples.helloworld.HelloReply sayHello(HelloRequest request) {
	return blockingUnaryCall(
	getChannel(), getSayHelloMethod(), getCallOptions(), request);
	}
	}

	public static abstract class GreeterImplBase implements io.grpc.BindableService {

	/**
	* Sends a greeting
	*/
	public void sayHello(HelloRequest request, StreamObserver<HelloReply> responseObserver) {
	asyncUnimplementedUnaryCall(getSayHelloMethod(), responseObserver);
	}

	@java.lang.Override
	public final io.grpc.ServerServiceDefinition bindService() {
	return io.grpc.ServerServiceDefinition.builder(getServiceDescriptor())
	.addMethod(
	getSayHelloMethod(),
	asyncUnaryCall(
	new MethodHandlers<
	io.grpc.examples.helloworld.HelloRequest,
	io.grpc.examples.helloworld.HelloReply>(
	this, METHODID_SAY_HELLO)))
	.build();
	}
	}

	// Sample response body
	{
	"query": "myQuery",
	"page_number": 42,
	"result_per_page": 100,
	"tickers": [
	{
	"name": "rPs",
	"value": 9.768923
	},
	{
	"name": "WEo",
	"value": 6.067048
	}
	]
	}

We Shouldn't Make REST APIs

We
Shouldn't
Make REST APIs