Skuteczna komunikacja w naszych aplikacjach, czy to w mikroserwisach, czy w monolicie, to kluczowa kwestia. A im większa skala i ilość danych, tym problem bardziej złożony. Podczas prezentacji wprowadzę Was w świat usług gRPC, omówimy na przykładzie sposób działania, znajdziemy jego mocne i słabe strony oraz porównamy gRPC do innych rozwiązań.

1. RG-DEV #14

3. MICHAŁ KRUCZEK
So ware Engineer & PHP Developer since 2010
bass guitarist and trumpeter
kruczek.it
Created by /Michał Kruczek @partikus

4. GRPC
HOW TO COMMUNICATE EFFECTIVELY?

5. AGENDA
Intro
The RPC story
gRPC
Demo

6. EFFECTIVE
COMMUNICATION
A two way information sharing process which
involves one party sending a message that is
easily understood by the receiving party.

7. Accounting
Boss
Employees
Warehouse

8. Store
Invoices
Reports
Warehouse

9. Order
InvoiceFactory
NotificationService

10. THE RPC STORY

11. ~1970 - RPC
~1980 - IMPLEMENTATION
~1990 - OOP & CORBA

12. WHAT'S RPC?
Remote Procedure Call (RPC) is a protocol that
one program can use to request a service from
a program located in another computer on a
network without having to understand the
network's details. A procedure call is also
sometimes known as a function call or a
subroutine call.

13. WHY RPC?
WRAPS NETWORKS INTERACTIONS
FLEXIBLE & MAINTAINABLE
EASY TO DEVELOP
DISTRIBUTED SYSTEMS

14. RPC'S DICTIONARY

15. STUBS
A stub in distributed computing is a piece of
code that converts parameters passed
between client and server during a remote
procedure call (RPC).

16. IDL
INTERFACE DEFINITION LANGUAGE
IDL is a specification language used to
describe a so ware component's application
programming interface (API)

17. CHALLANGE

18. PHP
GO
PYTHONJAVA

19. CONTRACT
CLIENTS' IMPLEMENTATIONS
SERVERS' STUBS
PERFORMANCE

20. GRPC
A HIGH PERFORMANCE,
OPEN-SOURCE UNIVERSAL RPC FRAMEWORK

24. WHY WOULD I WANT TO
USE GRPC?

25. LOW LATENCY, HIGHLY SCALABLE, DISTRIBUTED SYSTEMS.
DEVELOPING MOBILE CLIENTS WHICH ARE COMMUNICATING
TO A CLOUD SERVER.
DESIGNING A NEW PROTOCOL THAT NEEDS TO BE ACCURATE,
EFFICIENT AND LANGUAGE INDEPENDENT.
LAYERED DESIGN TO ENABLE EXTENSION EG.
AUTHENTICATION, LOAD BALANCING, LOGGING AND
MONITORING ETC.

26. HTTP/2

27. WHAT ARE THE KEY DIFFERENCES TO
HTTP/1.X?
IS BINARY, INSTEAD OF TEXTUAL
IS FULLY MULTIPLEXED, INSTEAD OF ORDERED AND BLOCKING
CAN THEREFORE USE ONE CONNECTION FOR PARALLELISM
USES HEADER COMPRESSION TO REDUCE OVERHEAD
ALLOWS SERVERS TO “PUSH” RESPONSES PROACTIVELY INTO
CLIENT CACHES

29. PROTOCOL BUFFERS
AS THE IDL

30. syntax = "proto3";
package Kruczek.RgDev.Twitter;
enum ResultType {
MIXED = 0;
RECENT = 1;
POPULAR = 2;
}
message Query {
string q = 1;
string since = 2;
int32 count = 3;
string lang = 4;
ResultType type = 5;
repeated string tracks = 6;
repeated string follows = 7;

31. ...
message Author {
string id = 1;
string name = 2;
string screenName = 3;
string avatar = 4;
}
message Tweet {
string id = 1;
string text = 2;
Author author = 3;
int32 retweetCount = 4;
int32 favoriteCount = 5;
}

32. SERVICE METHODS' TYPES

33. UNARY RPC
rpc SayHello(HelloRequest)
returns (HelloResponse) { }

34. SERVER STREAMING RPC
rpc LotsOfReplies(HelloRequest)
returns (stream HelloResponse) { }

35. CLIENT STREAMING RPC
rpc LotsOfGreetings(stream HelloRequest)
returns (HelloResponse) { }

36. BIDIRECTIONAL STREAMING RPC
rpc BidiHello(stream HelloRequest)
returns (stream HelloResponse) { }

37. PROS
IDIOMATIC CLIENT LIBRARIES IN 10 LANGUAGES
HIGHLY EFFICIENT ON WIRE AND WITH A SIMPLE SERVICE
DEFINITION FRAMEWORK
BI-DIRECTIONAL STREAMING WITH HTTP/2 BASED TRANSPORT
PLUGGABLE AUTH, TRACING, LOAD BALANCING AND HEALTH
CHECKING

38. CONS
MISSING PHP SERVER
MISSING OFFICIAL JS-WEB CLIENT

40. DEMO APP
TWITTER LIVE STREAMING

41. LET'S DEFINE A CONTRACT

42. syntax = "proto3";
package Kruczek.RgDev.Twitter;
service TwitterBoard {
rpc GetTweets(Query) returns (stream Tweet) {}
}
...

43. GENERATE PHP CLIENT
#!/usr/bin/env bash
set -ex
php_output="php/grpc"
rm -rf "$php_output" && mkdir -p "$php_output"
protoc
--php_out="$php_output"
--grpc_out="$php_output"
--plugin=protoc-gen-grpc=/usr/local/bin/grpc_php_plugin
twitter.proto

44. GENERATE NODEJS SERVER
#!/usr/bin/env bash
nodejs_output="nodejs/grpc"
rm -rf "$nodejs_output" && mkdir -p "$nodejs_output"
protoc
--js_out="import_style=commonjs,binary:$nodejs_output"
--grpc_out="$nodejs_output"
--plugin=protoc-gen-grpc=/usr/local/bin/grpc_node_plugin
twitter.proto

45. NODEJS SERVER THAT USES REST API

46. import grpc from "grpc";
import twitter from "twitter";
import twitterService from "./../server/twitter.service";
import services from "./../grpc/twitter_grpc_pb";
const client = new twitter(credentials);
const service = new twitterService(client);
function main() {
const server = new grpc.Server();
server.addService(services.TwitterBoardService, service);
server.bind('0.0.0.0:50052', grpc.ServerCredentials.createInsecure())
server.start();
}
main();

47. NODEJS SERVER THAT USES TWITTER
STREAMING

48. ANOTHER SERVICE IMPEMENTATION
...
import twitterService from "./../server/streamTwitter.service";
...

49. <?php
class Client
{
private $client;
public function __construct(string $hostname)
{
$this->client = new TwitterBoardClient($hostname, ['credentials' =
}
}

50. /**
* @param Query $query
* @return Generator|Tweet[]
*/
public function getTweets(Query $query): Generator
{
/** @var ServerStreamingCall $response */
$response = $this->client->GetTweets($query);
foreach ($response->responses() as $response) {
yield $response;
}
}

51. LIVE DEMO
LET'S TWEETS ;-)

52. QUESTIONS?
SLIDES: SLIDESHARE.NET/MICHASZCZUR
TWITTER: @PARTIKUS
HOMEPAGE: KRUCZEK.IT

53. THANKS!

54. LINKS
github.com/partikus/grpc-example
grpc.io
developers.google.com/protocol-buffers