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What is App Engine? O

What is App Engine? O






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    What is App Engine? O What is App Engine? O Presentation Transcript

    • What is App Engine? Ikai Lan OSCON July 21st, 2010 Twitter: @ikai
    • Agenda Topics we'll cover Why App Engine? Traditional web stack scalability App Engine to the rescue! Services and APIs Deployment steps App Engine and Open Source Questions and Next Steps
    • What is Google App Engine?
    • Google App Engine is... ... a way for you to run your web applications on Google’s scalable infrastructure. Google’s Data Centers
    • Start with... the basic LAMP stack LAMP: Linux Apache MySql Programming Language (PHP, Python, Perl, etc.) NOT Scalable Single Point of Failure (SPOF) Google Confidential and Proprietary
    • Database on a separate server Still not Scalable! TWO Single Points of Failure Google Confidential and Proprietary
    • Multiple Web Servers Now you need Load Balancing Database is still Single Point of Failure Google Confidential and Proprietary
    • Round Robin Load Balancing Register list of IPs with DNS DNS record is cached with a Time to Live (TTL) Google Confidential and Proprietary
    • Round Robin Load Balancing But the TTL takes time to propagate and might not be respected So if a machine goes down... :-( And the database is still SPOF Google Confidential and Proprietary
    • Master Slave Database :-) Better read throughput :-( Master is SPOF for writes :-( Master may die before replication Google Confidential and Proprietary
    • Partitioned Database :-) Better R/W throughput :-( More machines, more management :-( Re-architect data model :-( Rewrite queries Google Confidential and Proprietary
    • Why build it all yourself? Google Confidential and Proprietary
    • Why not use Google App Engine? Simple application configuration No systems administration No performance tuning AUTOMATIC SCALING! Google Confidential and Proprietary
    • The Cloud Computing Landscape SaaS PaaS IaaS Source: Gartner AADI Summit Dec 2009
    • App Engine Developers/Apps Google Confidential and Proprietary
    • Google Confidential and Proprietary
    • By the numbers Over 100,000 applications 250,000 developers Over 250 million daily pageviews
    • Underneath the hood
    • App Engine Components Load balancing Routing Hosts static content Separate from programming files Google Confidential and Proprietary
    • App Engine Components Hosts application code Handles concurrent requests Enforces isolation for app safety Maintains statelessness Multiple Runtimes Copyright © Sun Microsystems Inc. All rights reserved. Google Confidential and Proprietary
    • App Engine Services/APIs
    • Bigtable - The App Engine datastore Distributed, partitioned datastore Arbitrary horizontal scaling - scales to “Internet scale” Replicated and fault tolerant Parallel processing Predictable query performance No deadlocks Google Confidential and Proprietary
    • Memcache Distributed, very fast, in-memory cache Optimistic caching Very stable, robust and specialized Google Confidential and Proprietary
    • URL Fetch Simple, HTTP communication HTTP GET/POST to external service Allows integration with third-party REST APIs Google Confidential and Proprietary
    • Mail Inbound and outbound mail Outbound mail Inbound mail handling Attachment processing Google Confidential and Proprietary
    • XMPP Instant messaging for your application Incoming and outgoing XMPP No need to worry about setting up servers Google Confidential and Proprietary
    • Task Queue Background and scheduled computation Background processing infrastructure Scheduled jobs Automatic handling of queuing and job polling Google Confidential and Proprietary
    • Images Image manipulation Resize Crop Image compositions Google Confidential and Proprietary
    • Blobstore Heavy lifting for large files Upload and distribute large files Programmatic access to file contents Google Confidential and Proprietary
    • User Accounts Federated login for your application Google Accounts or OpenID Administrator management No need to create user management system Google Confidential and Proprietary
    • Getting started
    • Getting started with App Engine Download the SDK http://code.google.com/appengine Register for an Appspot account https://appengine.google.com Write code - deploy!
    • Starting a project Linux, MacOS, etc. command-line: $ dev_appserver.py helloworld # run dev svr $ appcfg.py update helloworld # deploy live Windows GUI (also avail for Mac):
    • Project contents app.yaml – main configuration file index.yaml – automatically generated to index your data main.py – your main application "controller" code goes here
    • main.py
    • Local development server $ dev_appserver.py helloworld (Can also use the launcher for Windows and OS X)
    • Deploying the application Set application identifier Run deploy script You're live!
    • main.py: Adding a handler from google.appengine.ext import webapp from google.appengine.ext.webapp.util import run_wsgi_app class MainHandler(webapp.RequestHandler): def get(self): self.response.out.write('<h1>Hello world!</h1>') self.response.out.write(''' <form action="/sign" method=post> <input type=text name=content> <br><input type=submit value="Sign Guestbook"> </form> ''') class GuestBook(webapp.RequestHandler): def post(self): self.response.out.write( '<h2>You wrote:</h2> %s' % self.request.get('content') ) application = webapp.WSGIApplication([ ('/', MainHandler), ('/sign', GuestBook), ], debug=True) # start_wsgi_app etc ...
    • main.py: Persisting to the datastore class GuestBook(webapp.RequestHandler): def post(self): greeting = Greeting() greeting.content = self.request.get('content') greeting.put() self.redirect('/')
    • main.py: Collecting values from the datastore class MainHandler(webapp.RequestHandler): def get(self): self.response.out.write('Hello world!') self.response.out.write('<h1>My GuestBook</h1><ol>') greetings = Greeting.all() for greeting in greetings: self.response.out.write('<li> %s' % greeting.content) self.response.out.write(''' </ol><hr> <form action="/sign" method=post> <textarea name=content rows=3 cols=60></textarea> <br><input type=submit value="Sign Guestbook"> </form> ''')
    • Running the deploy script $ appcfg.py update helloworld Scanning files on local disk. Initiating update. Email: ...
    • You're live!
    • Google App Engine and Open Source
    • TyphoonAE: Open Source implementation
    • Open Source JVM language runtimes Clojure Practical Lisp on the JVM JRuby/Mirah Ruby on the JVM. Mirah = Ruby-like language that compiles to Java (speed!) Groovy Dynamically typed Java-like language Scala Strongly typed, functional imperative Jython Java implementation of Python
    • Open Source Persistence Frameworks Objectify http://code.google.com/p/objectify-appengine/ Twig http://code.google.com/p/twig-persist/ Slim3 (popular in Japan) http://sites.google.com/site/slim3appengine/ SimpleDS http://code.google.com/p/simpleds/ Django-nonrel http://www.allbuttonspressed.com/projects/django- nonrel
    • Official features Datanucleus JDO/JPA http://code.google.com/p/datanucleus-appengine/ App Engine Map/Reduce http://code.google.com/p/appengine-mapreduce/ Python SDK Java SDK - soon!
    • Questions and Next Steps
    • Code time!
    • main.py: Skeleton application from google.appengine.ext import webapp from google.appengine.ext.webapp import util class MainHandler(webapp.RequestHandler): def get(self): self.response.out.write('Hello world!') def main(): application = webapp.WSGIApplication([('/', MainHandler)], debug=True) util.run_wsgi_app(application) if __name__ == '__main__': main()
    • Next steps Download the SDK http://code.google.com/appengine Do the codelab http://code.google.com/appengine Register for an Appspot account https://appengine.google.com Get this presentation http://slideshare.net/ikailan