Living In The CloudHosting Data & Apps Using The Google Infrastructure

Introductions

Pamela Fox

USC

Google

MS/BS CS

Introductions

http://www.wordle.net/gallery/wrdl/710650/fkedupmonkey_tags

The Cloud!

Tonight’s Agenda

Google Data APIs App Engine

Before the Cloud: Web Apps

After the Cloud: Web Apps

• Viral Spread

• Simultaneous Edits

• = Scaling Nightmare

Mo’ Users, Mo’ Problems

Solution: App Engine

What Is App Engine?

Lets you run your web application on top of Google’s infrastructure.

• Servers• Network• Datastore• Backups• Pagers

Scalable}

Why App Engine

“We wear pagers so you don’t have to.”

— Guido van Rossum

Simplicity

App Engine is designed to be simple.

Simple application configuration.

No systems administration.

No performance tuning.

Automatic scaling.

App Engine Architecture

code data

Non-Scalable Architecture

code/data

Python

Data Store

Data Store

db.GqlQuery("SELECT * FROM Shout " "WHERE who >= 'b' AND who < ' c ' " "ORDER BY when DESC").fetch(100)

query = Shout.all()query.order('-date')query.filter('who >=', 'b')query.filter('who <', ‘c')shouts = query.fetch(100)

Memcache

Users

@gmail.com

@myappsdomain.com

Demo

Google App Engine

Before the Cloud: User Apps

Before the Cloud: User Apps

• Users demand ownership of their content.

• Other sites want to access that content.

Damn Needy Users

Solution: Google data APIs

How Do You Make Things Accessible?

Application

Programming

Interface( )

APIs

An application programming interface (API) is a set of functions, procedures, methods or classes that an operating system, library or service provides to support requests made by computer programs.

Source: Wikipedia

C/C++ Header File

APIs

RPC || REST

* SOAP

Remote Procedure Calls

fooInstance->addNumbers(2, 3);

<?xml version="1.0"?><methodCall> <methodName>Foo.addNumbers</methodName> <params> <param> <value><int>2</int></value> <value><int>3</int></value> </param> </params></methodCall>

fooInstance.addNumbers(2, 3);

PHP

XML(Network)

C++

REST

Representational

State

Transfer( )[Fielding 2000]

REST

Fundamentals of REST:

Application state and functionality is abstracted into discrete resources.

REST

Fundamentals of REST:

Resources are accessible via URLs.

/blog/posts/1234

REST

Fundamentals of REST:

Resources share a uniform interface for transferring state.

HTTP://

GET POST

PUT DELETE

}

RSS/ATOM

Feed

{Entries

Example ATOM feed.

ATOMPub

Feed

{Entries

Google data APIs Protocol

Feed

Query

{Entries

The Google Data Protocol

REST

Google Data Protocol

RSS 2.0

Architecture

Syndication

UpdatesAtomPub

Atom

The Google Data Protocol

RSS 2.0 Atom(Pub)

Google Data

Syndication Format ✓ ✓ ✓

Queries ✓

Updates ✓ ✓

Optimistic Concurrency ✓

Authentication ✓

The Google Data Protocol

Over 15 APIs, 1 Protocol

Many Uses

Case Study: CalGoo

The Google Data Protocol

GET /myFeed

200 OK

<?xml version="1.0"?>

<feed xmlns="http://www.w3.org/2005/Atom">

<title>Foo</title>

<updated>2006-01-23T16:25:00-08:00</updated>

<id>http://www.example.com/myFeed</id>

<author>

<name>Jo March</name>

</author>

<link href="/myFeed" rel="self"/>

</feed>

Requesting a feed or resource

The Google Data Protocol

POST /myFeed

<?xml version="1.0"?>

<entry xmlns="http://www.w3.org/2005/Atom">

<author>

<name>Elizabeth Bennet</name>

<email>liz@gmail.com</email>

</author>

<title type="text">Entry 1</title>

<content type="text">This is my entry</content>

</entry>

Creating a new resource

The Google Data Protocol

201 CREATED

<?xml version="1.0"?>

<entry xmlns="http://www.w3.org/2005/Atom">

<id>http://www.example.com/id/1</id>

<link rel="edit" href="http://example.com/myFeed/1/1/"/>

<updated>2006-01-23T16:26:03-08:00</updated>

<author>

<name>Elizabeth Bennet</name>

<email>liz@gmail.com</email>

</author>

<title type="text">Entry 1</title>

<content type="text">This is my entry</content>

</entry>

Creating a new resource

The Google Data Protocol

PUT /myFeed/1/1/

<?xml version="1.0"?>

<entry xmlns="http://www.w3.org/2005/Atom">

<id>http://www.example.com/id/1</id>

<link rel="edit" href="http://example.com/myFeed/1/1/"/>

<updated>2006-01-23T16:28:05-08:00</updated>

<author>

<name>Elizabeth Bennet</name>

<email>liz@gmail.com</email>

</author>

<title type="text">Entry 1</title>

<content type="text">This is my first entry.</content>

</entry>

Updating an entry

The Google Data Protocol

200 OK

<?xml version="1.0"?>

<entry xmlns="http://www.w3.org/2005/Atom">

<id>http://www.example.com/id/1</id>

<link rel="edit" href="http://example.com/myFeed/1/2/"/>

<updated>2006-01-23T16:28:05-08:00</updated>

<author>

<name>Elizabeth Bennet</name>

<email>liz@gmail.com</email>

</author>

<title type="text">Entry 1</title>

<content type="text">This is my first entry.</content>

</entry>

Updating an entry

The Google Data Protocol

DELETE /myFeed/1/2/

200 OK

Updating an entry

Demo

Google Data CRUD

The Google Data Protocol

GET /myFeed?q=This

200 OK

<?xml version="1.0"?>

<feed xmlns="http://www.w3.org/2005/Atom">

<title>Foo</title>

<updated>2006-01-23T16:26:03-08:00</updated>

<id>http://www.example.com/myFeed</id>

<link href="/myFeed" rel="self"/>

<entry>

<id>http://www.example.com/id/1</id>

<link rel="edit" href="http://example.com/myFeed/1/1/"/>

<updated>2006-01-23T16:26:03-08:00</updated>

<title type="text">Entry 1</title>

<content type="text">This is my entry</content>

</entry>

</feed>

Searching for a resource

Demo

Youtube Searcher

JSON and RSS

Other formats are also supported:

?alt=json

?alt=json-in-script

?alt=kml

?alt=rss

http://code.google.com/apis/gdata/json.html

Client Libraries

PHP

.NET

Java

JavaScriptObjective-C

Python

+ Community Contributed

DemoGoogle Data Sample Applications

My Secret Motivation For Giving This Talk

Google Data APIs

♥App Engine

DemoGoogle Data APIs + App Engine

Questions?

Questions?

Pamela Foxpamelafox@google.com@pamelafox

More Infohttp://code.google.com

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