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REST Services with RabbitMQ, Spring Integration and Node.JS

Durai Arasan & Monish Unni

About Us

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Durai Arasan, Director, Architecture Monish Unni, Sr. Principal, Architecture

Contents

• Background • Why Queues? • Why RabbitMQ? • Spring Integration + Services • Why JAX-RS or REST? • Demo

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• What do web clients need? • Why Node.js? • Handling routes • Node transformations • Node aggregation • Demo

Background

• Speed • Multiple languages • Platform for legacy Services • Large number of Services • Mixed payload formats • Mixed protocols • Fault isolations • Logging • Usage reporting

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Architecture

DLX + AEProcess Python ProcessSI + CXF

Java ProcessC Process

Rabbit MQMessage Bus

SIJava Process Python Process

Client

AMQP

X

CP

C Process

Proc

ess

Man

ager

PC PCPCDLX + AEConsumer Process

Adm

in &

M

onito

rs

Security

Why Queues?

• Single queue makes every request at the mercy of previous requests.

• Traffic shaping or Quality of Service (QoS) • Valid response when server can’t handle requests

• Avoid “503 - Server too busy” • Monitoring pending requests • Administration of consumers based on load • Requests, response & fault isolation

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Why RabbitMQ?

• AMQP Compliant • RabbitMQ Extensions for enterprise

• Alternate exchange (AE) • Dead letter exchange (DLX) • Extended properties for Queues & Messages

• Built-in monitoring • Security (amqps) • Large number of connections • Binding for many languages • Built-in Spring support

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Spring Integration + Services

• Many great things in Spring Integration

• Custom service activators for • First class support of JAX-WS/RS services • Exception handling

• Custom namespace for • Simplified spring integration configuration • Gateways & Transformers • CXF Bridge

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Custom Service Activators

• IntegrationConversionService for CXF message • Inbound gateways lazy bind CXF Service Activators • CXF destination instead of local conduit • Provides JAX-WS and JAX-RS endpoints • Error handlers

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What is REST on AMQP?

basic.get and basic.publish

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Why JAX-RS on AMQP?

• Is JAX-RS about building HTTP based Restful services? • Is Transport Independence a bug or a feature?

• REST is not about using HTTP • Allows to leverage JAX-RS eco-system for AMQP

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JAX-RS Interfaces

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JAX-RS Configuration for AMQP

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Custom Spring Integration Gateway and namespace

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Demo

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What do web clients need?

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http:// webservices

Our Choice

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Why Node.js?

• Shines in I/O • Networking

• Naturally asynchronous • Javascript callback support

• Transformations • Choose your batteries

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Architecture

DLX + AEProcess Python ProcessSI + CXF

Java ProcessC Process

Rabbit MQMessage Bus

SIJava Process Python Process

Client

AMQP

X

CP

C Process

Proc

ess

Man

ager

PC PCPCDLX + AEConsumer Process

Adm

in &

M

onito

rs

Security

Node.js

AMQP

HTTPWeb

Handling routes

• RabbitMQ • Routes with exchange name and routing key • Backed by queues with binding key

• Node.js • Uses binding key list from RabbitMQ • url-template library matches incoming requests • Routes matching requests to RabbitMQ with headers

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Handling Routes

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Node.js RabbitMQ

GET/account/{id}

GET /account/120001

AMQP Headers - Routing Key - CXF Request URI - HTTP Method

AccountService

Route alias & Vanity URLs

• Advertising public APIs • Protecting internal service routes • HTTP attributes based methods need special mapping

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Node transformations

• Protocol conversion • Payload conversion • Declarative routes • Aggregation • Avoids boilerplate code

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Aggregation w/ async

• Composing control flow • series • parallel

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Other usage

• APIs • Expose services as APIs

• Testers • Can be used as test clients to different endpoints

• Mock Services • Virtualize any service without much effort

• Benchmarks • Built-in support for reporting

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Demo

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Calling legacy services API Routes Aggregation

Node - Things to watch out

• Primitive stack trace • vague errors “EADDRINFO”

• EventLoop • 2 line stack-trace : debug

• Debug with strace, dtrace • V8 Engine

• Generational GC • may need a deep dive

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Node - New and Good parts

• V8 native support for generators and yield! • looks very promising (no pun) • can remove crustified callback code

• function (err, callback) • forced to think about error and what to do

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Node libraries

• amqp • async • elementtree • soap • loopback • swagger

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Summary

• RabbitMQ • Scales to large number of connections • Fast & Secure • Binding for many languages

• Spring Integration • Easy to extend • Plugin service activators • In JVM orchestration

• Node.JS • Async I/O • Javascript support 30

Learn More. Stay Connected

We are Hiring! career.etrade.com

twitter.com/duraiarasan

linkedin.com/in/duraiarasan, linkedin.com/in/monishunni

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Q & A

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