You heard of "new thing" called gRPC and promises that it will solve all issues for you, so now you are not sure if you should use it for breaking up your monolith to Microservices. If it is good for Google it should be good for you also right? On the other hand, you have been using REST API's for some time now, at least as a consumer, so maybe this would be better approach in Microservices waters, or would it? Which one to chose and which one will fit your use case better? Join me in this talk were I will try to explain both approaches, good and bad. I will give some points and tips, which will help you in understanding better which one will be better for you. By doing this I will also share some best practices for both approaches

1. @kgd_net @VladimirD_42
REST API vs gRPC
Which One Should You Use
in Breaking a Monolith
Vladimir Dejanović
26 September 2018

2. @VladimirD_42
Vladimir Dejanović
Let’s Meet
@VladimirD_42
vladimir@itshark.xyz
http://itshark.xyz
@kgd_net

3. @VladimirD_42
Vladimir Dejanović
Let’s Meet
http://itshark.xyz
@kgd_net

4. @VladimirD_42
Vladimir Dejanović
Let’s Meet
@kgd_net

5. @VladimirD_42
Vladimir Dejanović
Let’s Meet
and Others...
@kgd_net

6. @VladimirD_42@kgd_net
Agenda

7. @VladimirD_42@kgd_net
Agenda
REST

8. @VladimirD_42@kgd_net
Agenda
gRPC
REST

9. @VladimirD_42@kgd_net
Agenda
gRPC
REST vs gRPC in breaking Monolith
REST

10. @VladimirD_42@kgd_net
Agenda
gRPC
Questions
REST vs gRPC in breaking Monolith
REST

11. @VladimirD_42@kgd_net
What is REST?

12. @VladimirD_42@kgd_net
REST

13. @VladimirD_42@kgd_net
REST
http://www.ics.uci.edu/~fielding/pubs/di
ssertation/rest_arch_style.htm

14. @VladimirD_42@kgd_net
REST
Client-Server Architecture

15. @VladimirD_42@kgd_net
REST
Statelessness
Client-Server Architecture

16. @VladimirD_42@kgd_net
REST
Cacheability
Statelessness
Client-Server Architecture

17. @VladimirD_42@kgd_net
REST
Cacheability
Layered System
Statelessness
Client-Server Architecture

18. @VladimirD_42@kgd_net
REST
Cacheability
Code on Demand (Optional)
Layered System
Statelessness
Client-Server Architecture

19. @VladimirD_42@kgd_net
REST
Cacheability
Code on Demand (Optional)
Layered System
Statelessness
Uniform Interface
Client-Server Architecture

20. @VladimirD_42@kgd_net
REST in Real Life

21. @VladimirD_42@kgd_net
REST in Real Life

22. @VladimirD_42@kgd_net
REST in Real Life

23. @VladimirD_42@kgd_net
REST in Real Life

24. @VladimirD_42@kgd_net
REST in Real Life
import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;
@RepositoryRestResource(collectionResourceRel = "people",
path = "people")
public interface PersonRepository
extends MongoRepository<Person, String> {
List<Person> findByLastName(@Param("name") String name);
}

25. @VladimirD_42@kgd_net
REST in Real Life
import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.data.rest.core.annotation.RepositoryRestResource;
@RepositoryRestResource(collectionResourceRel = "people",
path = "people")
public interface PersonRepository
extends MongoRepository<Person, String> {
List<Person> findByLastName(@Param("name") String name);
}

26. @VladimirD_42@kgd_net

27. @VladimirD_42@kgd_net
What is gRPC?

28. @VladimirD_42@kgd_net
gRPC
gRPC Remote Procedure Call

29. @VladimirD_42@kgd_net
Remote Procedure Call

30. @VladimirD_42@kgd_net
Remote Procedure Call
RMI

31. @VladimirD_42@kgd_net
Remote Procedure Call
RMI
CORBA

32. @VladimirD_42@kgd_net
https://grpc.io/img/landing-2.svg

33. @VladimirD_42@kgd_net
https://grpc.io/img/landing-2.svg

34. @VladimirD_42@kgd_net
https://grpc.io/img/landing-2.svg

35. @VladimirD_42@kgd_net
https://grpc.io/img/landing-2.svg

36. @VladimirD_42@kgd_net
https://grpc.io/img/landing-2.svg

37. @VladimirD_42@kgd_net
gRPC
C++

38. @VladimirD_42@kgd_net
gRPC
C++ Java

39. @VladimirD_42@kgd_net
gRPC
C++ Java Python

40. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go

41. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go Ruby

42. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go Ruby C#

43. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go
Node.js
Ruby C#

44. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go
Node.js
Ruby C#
Android Java

45. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go
Node.js
Ruby C#
Objective-CAndroid Java

46. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go
Node.js
Ruby C#
Objective-CAndroid Java
PHP

47. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go
Node.js
Ruby C#
Objective-CAndroid Java
PHP Dart

48. @VladimirD_42@kgd_net
gRPC
C++ Java Python
Go
Node.js
Ruby C#
Objective-CAndroid Java
PHP Dart

49. @VladimirD_42@kgd_net
REST vs gRPC
in breaking Monolith

50. @VladimirD_42@kgd_net

51. @VladimirD_42@kgd_net

52. @VladimirD_42@kgd_net

53. @VladimirD_42@kgd_net
ref:http://assets.bonappetit.com/photos/57d32e45bd794aa9132639a4/master/w_625,c_limit/lernert-sander-cubes-crop2.jpg

54. @VladimirD_42@kgd_net
REST vs gRPC

55. @VladimirD_42@kgd_net
REST vs gRPC

56. @VladimirD_42@kgd_net
REST vs gRPC

57. @VladimirD_42@kgd_net
REST vs gRPC
Both support multiple Languages

58. @VladimirD_42@kgd_net
REST vs gRPC
Both support multiple Languages
REST support much more

59. @VladimirD_42@kgd_net

60. @VladimirD_42@kgd_net

61. @VladimirD_42@kgd_net
REST vs gRPC
https://grpc.io/

62. @VladimirD_42@kgd_net
REST vs gRPC
https://grpc.io/
https://github.com/grpc/grpc-java

63. @VladimirD_42@kgd_net
gRPC

64. @VladimirD_42@kgd_net
gRPC

65. @VladimirD_42@kgd_net
gRPC

66. @VladimirD_42@kgd_net
gRPC

67. @VladimirD_42@kgd_net
gRPC

68. @VladimirD_42@kgd_net
gRPC

69. @VladimirD_42@kgd_net
gRPC

70. @VladimirD_42@kgd_net
gRPC

71. @VladimirD_42@kgd_net
gRPC

72. @VladimirD_42@kgd_net
REST vs gRPC
REST support more than 4 types

73. @VladimirD_42@kgd_net
gRPC

74. @VladimirD_42@kgd_net
gRPC
IDL

75. @VladimirD_42@kgd_net
REST vs gRPC
Schema is “optional” in REST

76. @VladimirD_42@kgd_net
REST vs gRPC
Schema is “optional” in REST
REST code or schema first

77. @VladimirD_42@kgd_net
REST vs gRPC
Schema is “optional” in REST
REST code or schema first
gRPC is schema first

78. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

79. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

80. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

81. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

82. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

83. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

84. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

85. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

86. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

87. @VladimirD_42@kgd_net
...
message TransferMoney {
int32 trans_id = 1;
int32 from_account_number = 2;
int32 to_account_number = 3;
double ammount = 4;
string message = 5;
}
service Bank {
rpc Transfer(TransferMoney) returns (TransferConfirmation);
rpc ListenToNotifications(Account) returns (stream AccountNotification);
rpc RequestTransfer(stream RequestMoney) returns (stream RequestStatus);
}
...

88. @VladimirD_42@kgd_net
gRPC
IDL
HTTP/2

89. @VladimirD_42@kgd_net
REST vs gRPC
HTTP2 backed into gRPC

90. @VladimirD_42@kgd_net
REST vs gRPC
HTTP2 backed into gRPC
Extra work “needed” for REST

91. @VladimirD_42@kgd_net
gRPC
IDL
HTTP/2
Protobuf 3

92. @VladimirD_42@kgd_net
Protocol Buffers
http://itshark.xyz/posts/2018/7/11/Proto
col_Buffers_basic_stuff_you_need_to_kn
ow

93. @VladimirD_42@kgd_net
Protocol Buffers
http://itshark.xyz/posts/2018/7/11/Proto
col_Buffers_basic_stuff_you_need_to_kn
ow
https://www.youtube.com/watch
?v=oDIkgNchrVY

94. @VladimirD_42@kgd_net
REST vs gRPC
REST is not JSON over HTTP

95. @VladimirD_42@kgd_net
REST vs gRPC
JSON Proto

96. @VladimirD_42@kgd_net
REST vs gRPC
JSON Proto ProtoJSON

97. @VladimirD_42@kgd_net
REST vs gRPC
JSON Proto

98. @VladimirD_42@kgd_net
REST vs gRPC
JSON Proto ProtoJSON

99. @VladimirD_42@kgd_net
REST vs gRPC
Protocol Buffer with REST

100. @VladimirD_42@kgd_net
Big Difference

101. @VladimirD_42@kgd_net
Big Difference
REST is about Resources

102. @VladimirD_42@kgd_net
Big Difference
REST is about Resources
RPC is about Remote Procedure Calls

103. @VladimirD_42@kgd_net

104. @VladimirD_42@kgd_net

105. @VladimirD_42@kgd_net

106. @VladimirD_42@kgd_net

107. @VladimirD_42@kgd_net

108. @VladimirD_42@kgd_net

109. @VladimirD_42@kgd_net

110. @VladimirD_42@kgd_net
gRPC code example
https://github.com/vladimir-dejanovic/g
rpc-bank-example

111. @VladimirD_42@kgd_net
REST vs gRPC

112. @VladimirD_42@kgd_net
REST vs gRPC

113. @VladimirD_42@kgd_net
REST vs gRPCWildWest

114. @VladimirD_42@kgd_net
REST vs gRPCWildWest
Law&Order

115. @VladimirD_42@kgd_net
REST vs gRPCWildWest
Law&Order
REST

116. @VladimirD_42@kgd_net
REST vs gRPCWildWest
Law&Order
REST

117. @VladimirD_42@kgd_net
REST vs gRPCWildWest
Law&Order
gRPCREST

118. @VladimirD_42@kgd_net
Some Questions

119. @VladimirD_42@kgd_net
Some Questions
Who will be consumers?

120. @VladimirD_42@kgd_net
Some Questions
Who will be consumers?
Mobile / Web / Other?

121. @VladimirD_42@kgd_net
Some Questions
What is the use case?

122. @VladimirD_42@kgd_net
Some Questions
What is the use case?
CRUD or Other?

123. @VladimirD_42@kgd_net
Some Questions
What are internal policies and rules?

124. @VladimirD_42@kgd_net
Some Questions
What are internal policies and rules?
Toward frameworks, protocols & others

125. @VladimirD_42@kgd_net
Some Questions
What is the problem
that you are solving?

126. @VladimirD_42@kgd_net
Thank You

127. @VladimirD_42
Questions
@VladimirD_42
vladimir@itshark.xyz
http://itshark.xyz
@kgd_net