This is the talk I presented on BrazilJS 2017.

1. MICROSERVICES USING
NODE.JS AND
RABBITMQ

3. Case

4. Share your location
with your friends

6. API
Back-end

7. Key = DevOps

8. Microservices
↓
Microdeployments

9. Reasons

10. Team

11. Architecture

12. Best
Practices

13. Code
Review

14. Tests

15. Continuous
Integration

16. Continuous
Delivery

17. Continuous
Monitoring

18. User Message
Lorem
Ipsum
Dolor
Sit
Amet

19. Libraries

20. Results
after
10 months

21. Startup
5 back-end developers
7 micro-services

22. Positives

23. New
technologies

24. Minimum
effort/impact

25. MySQL
MySQL
Postgre
SQL
Postgre
SQL
MySQL
Postgre
SQL
Postgre
SQL

26. Polyglot
Persistence

27. Decoupled
Code

28. Each
service has
a scope

29. Negatives

30. Shotgun
effect

32. Granular
Release

33. Unstable
Interfaces

34. User Message

35. Integration
Tests

36. Slow

37. Docker

38. New
developers

39. User-service
dependency

40. User Message
Lorem
Ipsum
Dolor
Sit
Amet

41. Lorem
Ipsum
Dolor
Amet

42. Microservices

44. Client Server

45. Server

46. 1 const express = require('express');
2 const bodyParser = require('body-parser');
3
4 const app = express();
5 app.use(bodyParser.json());
6
7 app.listen(3000, () => {
8 console.log(' [x] Awaiting for requests');
9 });
10
11 app.get('/:id', (request, response) => {
12 const id = request.params.id;
13
14 console.log(` [.] ID ${id}`);
15
16 response.status(200).json({
17 data: {
18 name: 'Ada Lovelace',
19 occupation: 'Programmer'
20 }
21 });
22 });

47. 1 app.listen(3000, () => {
2 console.log(' [x] Awaiting for requests');
3 });
4
5 app.get('/:id', (request, response) => {
6 const id = request.params.id;
7
8 console.log(` [.] ID ${id}`);
9
10 response.status(200).json({
11 data: {
12 name: 'Ada Lovelace',
13 occupation: 'Programmer'
14 }
15 });
16 });

48. Client

49. 1 const express = require('express');
2 const request = require('request-promise');
3
4 const id = process.argv.slice(2);
5
6 const app = express();
7
8 app.listen(3005, () => {
9 console.log(` [x] Requesting user ${id}`);
10
11 request(`http://localhost:3000/${id}`)
12 .then((res) => {
13 return console.log(` [.] Got ${res}`)
14 });
15 });

50. 1 const id = process.argv.slice(2);
2
3 app.listen(3005, () => {
4 console.log(` [x] Requesting user ${id}`);
5
6 request(`http://localhost:3000/${id}`)
7 .then((res) => {
8 return console.log(` [.] Got ${res}`)
9 });
10 });

51. Result

53. Client

54. Fault
resilience

55. Message
Broker

57. AMPQ
Advanced Message Queuing
Protocol

58. Exchange
asynchronous
messages

59. Reliability

60. RPC
Remote Procedure Call

62. Queueing

63. Client ServerRPC

64. Server

65. 1 const amqp = require('amqplib/callback_api');
2
3 amqp.connect('amqp://localhost', (err, conn) => {
4 conn.createChannel((err, ch) => {
5 const q = 'rpc_queue';
6
7 ch.assertQueue(q, { durable: false });
8 ch.prefetch(1);
9
10 console.log(' [x] Awaiting RPC requests');
11
12 ch.consume(q, function reply(msg) {
13 const id = parseInt(msg.content.toString(), 10);
14
15 console.log(` [.] ID ${id}`);
16
17 ch.sendToQueue(msg.properties.replyTo,
18 new Buffer('name: Ada Lovelace, occupation: programmer'),
19 { correlationId: msg.properties.correlationId });
20
21 ch.ack(msg);
22 });
23 });
24 });

66. rpc_queue
Response
Channel
3 amqp.connect('amqp://localhost', (err, conn) => {
4 conn.createChannel((err, ch) => {
5 const q = 'rpc_queue';

67. Retrieve message
from rpc_queue
12 ch.consume(q, function reply(msg) {
13 const id = parseInt(msg.content.toString(), 10);
14
15 console.log(` [.] ID ${id}`);

68. Send response
to callback queue
17 ch.sendToQueue(msg.properties.replyTo,
18 new Buffer('name: Ada Lovelace, occupation:
programmer’),
19 { correlationId: msg.properties.correlationId });

69. Client

70. 1 const amqp = require('amqplib/callback_api');
2 const uuid = require('uuid');
3
4 const id = process.argv.slice(2);
5
6 amqp.connect('amqp://localhost', (err, conn) => {
7 conn.createChannel((err, ch) => {
8 ch.assertQueue('', { exclusive: true }, (err, q) => {
9
10 const corr = uuid();
11 console.log(` [x] Requesting user ${id}`);
12
13 ch.consume(q.queue, (msg) => {
14 if (msg.properties.correlationId === corr) {
15 console.log(` [.] Got ${msg.content.toString()}`);
16 setTimeout(function() { conn.close(); process.exit(0) }, 500);
17 }
18 }, {noAck: true});
19
20 ch.sendToQueue('rpc_queue',
21 new Buffer(id.toString()),
22 { correlationId: corr, replyTo: q.queue });
23 });
24 });
25 });

71. Callback Queue
Request
Channel
6 amqp.connect('amqp://localhost', (err, conn) => {
7 conn.createChannel((err, ch) => {
8 ch.assertQueue('', { exclusive: true }, (err, q) => {

72. Request to rpc_queue
10 const corr = uuid();
20 ch.sendToQueue('rpc_queue',
21 new Buffer(id.toString()),
22 { correlationId: corr, replyTo: q.queue });

73. Retrieve response
from callback queue
13 ch.consume(q.queue, (msg) => {
14 if (msg.properties.correlationId === corr) {
15 console.log(` [.] Got ${msg.content.toString()}`);
16 setTimeout(function() { conn.close();
process.exit(0) }, 500);
17 }
18 }, {noAck: true});

74. Result

76. Scalability

77. Round-Robin

78. Queues
Performance

79. Conclusion

81. Any organization that designs a system (defined broadly)
will produce a design whose structure is a copy of the
organization's communication structure.
Conway's Law

82. Engineering

83. Trade-Off

84. How to solve
my team
problems?

85. Shotgun effect
Unstable interfaces
Integration tests
User-service
dependency

86. Monolith

87. Partially

88. User Message
Lorem
Ipsum
Dolor
Sit Amet

89. User LoremIpsum

90. Shotgun effect
Unstable interfaces
Integration tests
User-service
dependency

91. Community

98. Let technology empower
you!

99. Thanks!

100. https://github.com/carolpc
https://twitter.com/CarolinaPascale
carolina.pascale.c@gmail.com