Google App Engine
Flying into Munich

Dion Almaer
twitter.com/dalmaer
almaer.com

Don't forget, RIA's have rich
internet back-ends (RIBs?)
Jonathan Schwartz
CEO, Sun Microsystems

Google App Engine
Running Web Apps on Google’s Infrastructure
• Fully-integrated
application environment
• Language agnostic runtime
Python for now
• Free quota of 5M
pageviews per month
code.google.com/appengine

Google App Engine
Technical Challenges

Google App Engine
Financial and Admin Challenges

Google App Engine
Easy to use, Easy to scale, Free to start

Google App Engine
Free Quota and Expected Pricing
Resource Free Quota Additional
CPU 10-12¢ / core-hour
Storage Equivalent to 5M 15-18¢ / GB-month
pageviews / month
Bandwidth, Outgoing for a typical app 11-13¢ / GB transferred
Bandwidth, Incoming 9-11¢ / GB transferred
11

Google App Engine
Free Quota and Expected Pricing
eo rge!
an ks G
Th
Resource Free Quota Additional
CPU 1 euro / core-year
Storage Equivalent to 5M 1 euro / GB-decade
pageviews / month
Bandwidth, Outgoing for a typical app 1 euro / PB transferred
Bandwidth, Incoming 1 euro / PB transferred
13

Develop locally. Deploy to Google. Launch.

Develop locally. Deploy to Google. Launch.
Deploy

Develop locally. Deploy to Google. Launch.

Develop locally.
• Google App Engine SDK is open source
• Simulates production environment
•dev_appserver.py myapp
•appcfg.py update myapp

Hello World
Simplest output, simplest config
# helloworld.py
print \"Content-Type: text/html\"
print
print \"Hello, world!\"
# app.yaml
application: dalmaer-helloworld
version: 1
runtime: python
api_version: 1
handlers:
- url: /.*
script: helloworld.py

loadcontacts
var contacts = [
{ id: 1, name: ‘Dion Almaer’, ... },
{ id: 2, name: ‘Ben Galbraith’, ... },
savecontact ]
name=’Dion A Lamer’
email=’dion@almaer.com’
Web Services

threads
sockets
files
foreground
the snake is almost there

from django import v0_96 as django

Store data
Scalable, and not like a RDBMS
Wow, that's a
big table!

• No joins
• Hierarchies
• Indexes

Data Model
Just an object
from google.appengine.ext import db
class Story(db.Model):
title = db.StringProperty()
body = db.TextProperty(required=True)
author = db.UserProperty(required=True)
created = db.DateTimeProperty(auto_now_add=True)
rating = db.RatingProperty()
# Many other types: BlobProperty, ReferenceProperty, EmailProperty, PhoneProperty, IMProperty,
PostallAddressProperty, etc.

GQL
Our query language
SELECT *
FROM Story
WHERE title = 'App Engine Launch'
AND author = :current_user
AND rating >= 10
ORDER BY rating, created DESC

Run the queries
Beyond GQL
Story.gql(GQL_FROM_BEFORE,
current_user = users.get_current_user())
query = Story.all()
query.filter('title =', 'Foo')
.order('-date')
.ancestor(key)

Inserts
Manipulating the data
story = Story(
title = 'Morning Glory',
body = '....',
author = users.get_current_user(),
)
story.put() # save or update
story.delete() # delete if saved

Call Web Services

URL Fetch API
Aint no urllib2
from google.appengine.api import urlfetch
some_feed = urlfetch.fetch('http://somesite.com/rss')
if some_feed.status_code == 200:
self.response.out.write(some_feed.content)
53
421

Authenticate to Google
OpenID provider.... available

Users API
But you can do your own thing too of course...
from google.appengine.api import users
current_user = users.get_current_user()
if not current_user:
self.redirect(users.create_login_url('/
current_url'))
nickname = current_user.nickname()
email = current_user.email()
if users.is_current_user_admin():
...

Send Email

Email API
No SMTP config required
from google.appengine.api import mail
def post(self):
email_body = self.request.get('email_body')
sender = users.get_current_user().email
mail.send_mail(sender=sender,
to='marce@google.com',
subject='Wiki Page',
body=email_body)
self.response.out.write('Email Sent')

Manipulate Images

Image Manipulation API
No SMTP config required
# in model
avatar = db.BlobProperty()
# in handler
avatar = images.resize(self.request.get(\"img\"), 32,
32)
# available
resize
crop
rotate
horizontal_flip
vertical_flip
im_feeling_lucky :)

Memcache Support
In-memory distributed cache

Memcache API
In-memory distributed cache
from google.appengine.api import memcache
def get_data():
data = memcache.get(\"key\")
if data is not None:
return data
else:
data = self.query_for_data()
memcache.add(\"key\", data, 60)
return data
# Set several values, overwriting any existing values for these keys.
memcache.set_multi({ \"USA_98105\": \"raining\",
\"USA_94105\": \"foggy\",
\"USA_94043\": \"sunny\" },
key_prefix=\"weather_\", time=3600)
# Atomically increment an integer value.
memcache.set(key=\"counter\", 0)
memcache.incr(\"counter\")
memcache.incr(\"counter\")
memcache.incr(\"counter\")

Google App Engine
Areas of Work, Including…
• Offline Processing
• Rich Media Support
– e.g., large file upload / download
• Add’l Infrastructure Services
• What would you like to see?
40

Use it as you will
No need to go whole hog

Your Application
Web Services

Google App Engine
Announcing Open Signups

Python
Runtime
Web
Configuration
Applications
Static Files URL Fetch API
Google App
Engine
Email API Users API
Memcache API Image API

What if popular JavaScript libraries
were available and shared in the browser?
1 Now hosting open source JavaScript libraries at Google
Starting with: Prototype, Script.aculo.us, jQuery, Dojo, Mootools
Accepting requests for other open source libraries
Can access directly:
ajax.googleapis.com/ajax/lib/prototype?v=1.6.0.2&packed=false
Can access via AJAX API Loader:
google.load(“prototype”, “1.6”);
2 Other features
Automatic compression
Minification of libraries
Not tied to Google Code

Python
Runtime
Web
Configuration
Applications
Static Files URL Fetch API
Google App
Engine
Email API Users API
Memcache API Image API