This document summarizes a presentation comparing gRPC and REST by Alex Borysov and Mykyta Protsenko. It begins with introductions of the presenters and their backgrounds. It then discusses key differences between gRPC and REST such as gRPC using protocol buffers for defining APIs and being non-blocking via streaming, while REST focuses on resources and uses JSON/HTTP. Examples are provided of implementing services and clients for both approaches. Challenges of microservices and distributed systems that both aim to address are also covered.
The Role of Taxonomy and Ontology in Semantic Layers - Heather Hedden.pdf
gRPC vs REST: let the battle begin!
1. gRPC vs REST: let the battle begin!
JavaDay, November 4, 2017
Alex Borysov, Software Engineer @ Google
Mykyta Protsenko, Software Engineer @ Roku
2. Who are we?
Mykyta Protsenko
Software Engineer @ Roku
• passionate about all things scalable
• 18+ years in software engineering
• Author of Henka
REST vs gRPC
Alex Borysov
Software Engineer @ Google
• large scale systems developer
• 11+ years in software engineering
• Active gRPC user
REST vs gRPC
@aiborisov
@mykyta_p
5. I am getting frustrated by the number of people calling any
HTTP-based interface a REST API.
Roy Fielding
http://roy.gbiv.com/untangled/2008/rest-apis-must-be-hypertext-driven
@aiborisov
@mykyta_p
8. RESTful API
GET /user/15
{
“name”: “John Doe”,
“email”:“john.doe@gmail.com”,
...
}
non-RESTful API
GET /last_search?page=2
{
“products”: [...]
...
}
@aiborisov
@mykyta_p
9. What is gRPC?
gRPC stands for gRPC Remote Procedure Calls.
A high performance, general purpose, feature-rich
RPC framework.
Part of Cloud Native Computing Foundation cncf.io
HTTP/2 and mobile first.
Open sourced version of Stubby RPC used in Google.
@aiborisov
@mykyta_p
11. gRPC is not RMI
Maitainability
Ease of use
Performance
Scalability
L
e
s
s
o
n
s
Years of using Stubby
@aiborisov
@mykyta_p
12. What is gRPC?
Abstractions and best practices on how to design
RPCs.
Default implementation(s) from Google.
Extension points to plug custom implementations and
modifications.
Supports 10+ programming languages.
@aiborisov
@mykyta_p
19. Microservices?
How to draw an owl?
How to build microservices?
Draw some circles.
Take XYZ framework.
@aiborisov
@mykyta_p
20. Microservices?
How to draw an owl?
How to build microservices?
Draw the REST of the owlDraw some circles.
Take XYZ framework.
@aiborisov
@mykyta_p
21. Microservices?
How to draw an owl?
How to build microservices?
Draw the REST of the owl
Write your microservices!
Draw some circles.
Take XYZ framework.
@aiborisov
@mykyta_p
38. A distributed system is one in which the failure of a
computer you didn't even know existed can render your own
computer unusable.
Leslie Lamport, 1987
https://www.microsoft.com/en-us/research/wp-content/uploads/2016/12/Distribution.pdf
@aiborisov
@mykyta_p
49. REST: Service
public class AggregatingService {
public AggregatedContent fetch(int id) {
...
return new AggregatedContent(...);
}
}
public class AggregatedContent {
private final Integer id; // 115
private final String type; // ZRADA
private final String content; // Политики украли у детей...
private final Integer nextId; // 116
@aiborisov
@mykyta_p
50. REST: Service
public class AggregatingService {
public AggregatedContent fetch(int id) {
...
return new AggregatedContent(...);
}
}
public class AggregatedContent {
private Integer id;
private String type;
private String content;
private Integer nextId;
@aiborisov
@mykyta_p
51. REST: Service
public class AggregatingService {
public AggregatedContent fetch(int id) {
...
return new AggregatedContent(...);
}
}
public class AggregatedContent {
private Integer id; // 115
private String type; // ZRADA
private String content; // EJB 2.1
private Integer nextId; // 116
@aiborisov
@mykyta_p
52. REST: Service
public class AggregatingService {
public AggregatedContent fetch(int id) {
...
return new AggregatedContent(...);
}
}
public class AggregatedContent {
private Integer id; // 115
private String type; // ZRADA
private String content; // EJB 2.1
private Integer nextId; // 116
@aiborisov
@mykyta_p
53. REST: Controller
@GetMapping(
value = "/content/{id}",
produces = "application/json")
public AggregatedContent aggregated(@PathVariable("id") int id) {
return aggregatingService.fetch(id);
}
@aiborisov
@mykyta_p
54. REST: It’s All About Resources
@GetMapping(
value = "/content/{id}",
produces = "application/json")
public AggregatedContent aggregated(@PathVariable("id") int id) {
return aggregatingService.fetch(id);
}
@aiborisov
@mykyta_p
68. Implement gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void get(AggregationRequest request,
StreamObserver<AggregationResponse> responseObserver) {
}
}
@aiborisov
@mykyta_p
69. Implement gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void get(AggregationRequest request,
StreamObserver<AggregationResponse> responseObserver) {
}
}
70. Implement gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void get(AggregationRequest request,
StreamObserver<AggregationResponse> responseObserver) {
}
}
@aiborisov
@mykyta_p
71. Thread #X
Thread ...
Thread #7
Thread #6
Thread #5
Thread #4
Blocking API (aka Thread-per-Request)?
Thread #3
Thread #2
Thread #1
Thread pool
of size X
@aiborisov
@mykyta_p
72. Thread #X
Thread ...
Thread #7
Thread #6
Thread #5
Thread #4
Blocking API (aka Thread-per-Request)?
Thread #3
Thread #2
Thread #1
Thread pool
of size X
1
@aiborisov
@mykyta_p
73. Thread #X
Thread ...
Thread #7
Thread #6
Thread #5
Thread #4
Blocking API (aka Thread-per-Request)?
Thread #3
Thread #2
Thread #1
Thread pool
of size X
1
2
@aiborisov
@mykyta_p
74. Thread #X
Thread ...
Thread #7
Thread #6
Thread #5
Thread #4
Blocking API (aka Thread-per-Request)?
Thread #3
Thread #2
Thread #1
Thread pool
of size X
1
2
3
@aiborisov
@mykyta_p
75. Thread #X
Thread ...
Thread #7
Thread #6
Thread #5
Thread #4
Thread #3
Thread #2
Blocking API (aka Thread-per-Request)?
Thread #1
Thread pool
of size X
1
2
3
X
. . .
@aiborisov
@mykyta_p
76. Thread #X
Thread ...
Thread #7
Thread #6
Thread #5
Thread #4
Thread #3
Thread #2
Blocking API (aka Thread-per-Request)?
Thread #1
Thread pool
of size X
1
2
3
X
. . .
X + 1
@aiborisov
@mykyta_p
77. Thread #X
Thread ...
Thread #7
Thread #6
Thread #5
Thread #4
Thread #3
Thread #2
Blocking API (aka Thread-per-Request)?
Thread #1
Thread pool
of size X
1
2
3
X
. . .
X + 1
@aiborisov
@mykyta_p
78. Implement gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void get(AggregationRequest request,
StreamObserver<AggregationResponse> responseObserver) {
}
}
@aiborisov
@mykyta_p
79. Implement gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void get(AggregationRequest request,
public interface StreamObserver<AggregationResponse> responseObserver){{
void onNext(AggregationResponse response);
void onCompleted();
void onError(Throwable error);
}
}
}
@aiborisov
@mykyta_p
96. Streaming gRPC Service
public class AggregationService extends AggregationServiceImplBase {
private final Collection<ContentServiceStub> contentStubs;
public AggregationService(Collection<ContentServiceStub> contentStubs) {
this.contentStubs = contentStubs;
}
...
@aiborisov
@mykyta_p
97. Streaming gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void subscribe(AggregationRequest request,StreamObserver<AggregationResponse> responseObserver) {
contentStubs.forEach(stub -> { stub.subscribe(ContentRequest.getDefaultInstance(),
new StreamObserver<ContentResponse>() {
@Override
public void onNext(ContentResponse response) {
...
}
@Override
public void onError(Throwable error) {
responseObserver.onError(error);
}
@Override
public void onCompleted() {}
});
});
}
@aiborisov
@mykyta_p
98. Streaming gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void subscribe(AggregationRequest request,StreamObserver<AggregationResponse> responseObserver) {
contentStubs.forEach(stub -> { stub.subscribe(ContentRequest.getDefaultInstance(),
new StreamObserver<ContentResponse>() {
@Override
public void onNext(ContentResponse response) {
...
}
@Override
public void onError(Throwable error) {
responseObserver.onError(error);
}
@Override
public void onCompleted() {}
});
});
}
@aiborisov
@mykyta_p
99. Streaming gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void subscribe(AggregationRequest request,StreamObserver<AggregationResponse> responseObserver) {
contentStubs.forEach(stub -> { stub.subscribe(ContentRequest.getDefaultInstance(),
new StreamObserver<ContentResponse>() {
@Override
public void onNext(ContentResponse response) {
...
}
@Override
public void onError(Throwable error) {
responseObserver.onError(error);
}
@Override
public void onCompleted() {}
});
});
}
@aiborisov
@mykyta_p
100. Streaming gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void subscribe(AggregationRequest request,StreamObserver<AggregationResponse> responseObserver) {
contentStubs.forEach(stub -> { stub.subscribe(ContentRequest.getDefaultInstance(),
new StreamObserver<ContentResponse>() {
@Override
public void onNext(ContentResponse response) {
...
}
@Override
public void onError(Throwable error) {
responseObserver.onError(error);
}
@Override
public void onCompleted() {}
});
});
}
@aiborisov
@mykyta_p
101. Streaming gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void subscribe(AggregationRequest request,StreamObserver<AggregationResponse> responseObserver) {
contentStubs.forEach(stub -> { stub.subscribe(ContentRequest.getDefaultInstance(),
new StreamObserver<ContentResponse>() {
@Override
public void onNext(ContentResponse response) {
ResponseType type = typeForStub(stub);
int aggregationId = aggregationId(response.getId(), type);
AggregationResponse aggrResponse =
AggregationResponse.newBuilder()
.setContent(response.getContent()).setId(aggregationId).
.setType(type).build();
responseObserver.onNext(aggrResponse);
}
});
});
}
@aiborisov
@mykyta_p
102. Streaming gRPC Service
public class AggregationService extends AggregationServiceImplBase {
@Override
public void subscribe(AggregationRequest request,StreamObserver<AggregationResponse> responseObserver) {
contentStubs.forEach(stub -> { stub.subscribe(ContentRequest.getDefaultInstance(),
new StreamObserver<ContentResponse>() {
@Override
public void onNext(ContentResponse response) {
ResponseType type = typeForStub(stub);
int aggregationId = aggregationId(response.getId(), type);
AggregationResponse aggrResponse =
AggregationResponse.newBuilder()
.setContent(response.getContent()).setId(aggregationId).
.setType(type).build();
responseObserver.onNext(aggrResponse);
}
});
});
}
@aiborisov
@mykyta_p
127. Serverless
pay as you go
Func
Funcinput
...
Func
input
...
input
@aiborisov
@mykyta_p
128. All about resources
IDL optional
Synchronous by default
Unary
Perfect fit for serverless
All about APIs
IDL centric
Asynchronous by nature
Streaming or Unary
Performance first
REST gRPC
@aiborisov
@mykyta_p
185. All about resources
Synchronous and unary
Simplicity first
External fault-tolerance
Production ready
All about APIs
Async and streaming
Performance first
Built-in fault-tolerance
Production ready
REST gRPC
@aiborisov
@mykyta_p
186. All about resources
Synchronous and unary
Simplicity first
External fault-tolerance
Production ready
All about APIs
Async and streaming
Performance first
Built-in fault-tolerance
Production ready
REST gRPC
Be pragmatic,
start with your problem!
@aiborisov
@mykyta_p