Bruno PedroNovember 2015

Asynchronous Microservices in node.js

Summary• why microservices

• synchronous vs asynchronous topologies

• broker approach

• code examples

• patterns

Why Microservices• organised around business capabilities

• following a decentralised governance

• and a decentralised data management

• automated infrastructure

• designed for failure

in Martin Fowler, "Microservices"

Microservices

• loosely coupled

• with a specific responsibility

• designed around business needs

• connected through a common interface

HTTP

HTTP

HTTP

HTTP

Synchronous

Latency

Asynchronous

Asynchronous

Complexity

SMTPA

A

Broker

SMTPA

BC

D

E

AB

D C

E

Really?

AMQP• Advanced Message Queueing Protocol

• interoperable: loosely coupled clients and servers

• advanced publish and subscribe

• transactional, if needed

• supported by node.js

AMQP

AMQP

amqplib

AMQP

amqplib

var amqp = require('amqplib/callback_api');

amqp.connect('amqp://localhost', function(err, conn) { conn.createChannel(function(err, ch) { var q = 'hello';

ch.assertQueue(q, {durable: false}); ch.sendToQueue(q, new Buffer('Hello World!')); console.log(" [x] Sent 'Hello World!'"); }); });

in RabbitMQ Tutorials

AMQP

amqplibvar amqp = require('amqplib/callback_api');

amqp.connect('amqp://localhost', function(err, conn) { conn.createChannel(function(err, ch) { var q = 'hello';

ch.assertQueue(q, {durable: false}); console.log(" [*] Waiting for messages in %s.", q); ch.consume(q, function(msg) { console.log(" [x] Received %s”, msg.content.toString()); }, {noAck: true}); }); });

in RabbitMQ Tutorials

AMQP HTTP

Webhook

Patterns• work queue

• pubsub system

• webhook

• message routing

• backpressure

• RPC

Asynchronous Microservices• loosely coupled

• agile to changes

• event based

• organised around business capabilities

• connected through the message broker

AMQP

Wrap-up• microservices advantages

• asynchronous over synchronous

• broker approach

• easy to implement

• patterns

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Sean O’ConnorLead Engineer

It's great to see a tool like API Changelog come along. (…) as an API provider, it's always

a challenge to communicate to users when changes happen.

bpedro@apichangelog.com

Get in touch!

Bruno Pedro

Thank you