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node.js and ql.io

Build Your Own HTTP APIs for Agility and Scale

OSCON July 20, 2012

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Subbu Allamaraju@sallamargithub.com/s3u

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Jon LeBlanc@jcleblancgithub.com/jcleblanc

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How to consume HTTP APIs

cheaply and efficiently

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curl -X <HTTP method> <URI>

Real code (randomized)

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Find things from AFor each thing, find details from BFor each thing, find more details from CMerge results

Use case:

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Find productsFind dominant categories of productsLook up category info Merge categories with products

Use case:

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Get stuff from AIf A is down, try from BAnnotate stuff with other stuff from CIgnore some things from the stuffJoin all

Use case:

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Prod

ucer

sClie

nt

[Really important client]

Why don't you give me an API optimized for my use cases?

Serv

er

[Really important producer]

Thanks. Get a number and stand in the line!

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Prod

ucer

sClie

nt

Serv

er

[Really important producer]

Thanks. Get a number and stand in the line!

Who gets to decide the right thing?

[Really important client]

Why don't you give me an API optimized for my use cases?

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Build Your Own Optimized APIs

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https://github.com/ql-io/

ql.ioPlatform Engineering

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A domain specific language for HTTP client programming

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cut down lines of code

reduce no of requests

save bandwidth

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http://ql.io/console

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ServerWeb Node.js

ql.io Installation Modes

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curl http://<host>/q?s=query

As a Standalone Server

Node Host

ql.io

Data (intern

al)

Data (external)

# As a node.js modulenpm install ql.io-engine

// Use ql.io from node.jsvar Engine = require('ql.io-engine');var engine = new Engine({

//OPTIONS});

var script = '…';engine.execute(script, function(emitter){ emitter.on("end", function(err, res){ … });});

Language: Defining a Data Source

Include in .ql fileInclude in Request

Example: Mustache Templates

Example: jQuery for Cross Domain Reqs

Let’s Do It!

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1. Interop via HTTP

2. SQL inspired3. Implicit

orchestration4. Failure modes5. Consumer

oriented

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code

https://github.com/ql-io/ql.iodocs/demos

http://ql.iohttps://github.com/

jcleblanc/api-masherblog

http://ql-io.github.com