PyCon India 2010 Building Scalable apps using appengine
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This document discusses building scalable apps using Google App Engine. It introduces Google App Engine and shows a simple "Hello World" app written in Python. It describes how App Engine uses the Datastore for scalable data storage and modeling data with entities and properties. It also covers caching with Memcache and techniques for scaling apps, including using entity groups, batches, sharding, and caching.
![Hello World :) from google.appengine.ext import webapp from google.appengine.ext.webapp.util import run_wsgi_app class MainPage(webapp.RequestHandler): def get(self): self.response.headers[' Content-Type '] = ' text/plain ' self.response.out.write(' Hello, webapp World! ') application = webapp.WSGIApplication( [(' / ', MainPage)], debug= True ) def main(): run_wsgi_app(application) if __name__ == " __main__ ": main()](https://image.slidesharecdn.com/pycon2010scalableappsusingappengine-110416122343-phpapp02/85/PyCon-India-2010-Building-Scalable-apps-using-appengine-5-320.jpg)
PyCon India 2010 Building Scalable apps using appengine
- 1. Building Scalable Apps using Google App Engine Pranav Prakash bit.ly/scalableapps PyCon India 2010
- 2. Agenda Scalabality Introduction to Google App Engine Hello World App Engine DataStore Cache Scalability Revisited Case Study Q-n-A
- 3. Scalability Scaling Up Scaling Out
- 4. Google App Engine Develop, Deploy web apps on Google's Infrastructure Application Environment Sandbox Environment Runtime Environment Python Java DataStore Google Accounts Services Cron Jobs and Task Queues
- 5. Hello World :) from google.appengine.ext import webapp from google.appengine.ext.webapp.util import run_wsgi_app class MainPage(webapp.RequestHandler): def get(self): self.response.headers[' Content-Type '] = ' text/plain ' self.response.out.write(' Hello, webapp World! ') application = webapp.WSGIApplication( [(' / ', MainPage)], debug= True ) def main(): run_wsgi_app(application) if __name__ == " __main__ ": main()
- 6. app.yaml application : helloworld version : 1 runtime : python api_version : 1 handlers : - url : /.* script : helloworld.py
- 7. App Engine Datastore Scalable data storage for your applications Write once, read many Stores data entities with properties, organised by application defined Kinds Queries on entities of same kind Filter and sort order on property values and keys Pre-Indexing
- 8. Entities and Models Datastore Entity = key + set(attributes) Models describe the kind of data an app uses from google.appengine.ext import db import datetime class Person(db.Model): name = db.StringProperty(required= True ) birthdate = db.DateProperty() height = db.IntegerProperty() is_admin = db.BooleanProperty(default= False ) ted = Person(key_name='person_ted', name=' Ted ', birthdate=datetime.datetime(1986,12,04), height = 185) db.put(ted)
- 9. Entity Groups, Ancestors and Path Entities residing in same part of the distributed network Transactions Parent Child relationship Path and Key uniqueness
- 10. Fetching Entities GQL GqlQuery Query db.get() all_teds = Person.gql( “ WHERE name = :1 ” , “ Ted ” ).fetch(100) all_teds_1 = GqlQuery( “ SELECT * FROM Person WHERE name = :1 ” , “ Ted ” ).fetch(100) all_teds = Person.all().filter( “ name = “ , “ Ted ” ).fetch(100) specific_ted = Person.get_by_key_name(' person_ted ') specific_teds_key = db.Key(' Person ', ' person_ted ') specfic_ted_1 = db.get(specific_ted_key)
- 11. Cache Memcache App Caching
- 12. Scalability Revisited Read and Write Infrequently Keys, Key Names, ID Batch Reads and Writes Small Entity Groups Sharding Memcache
- 13. Case Study Social apps and games from Oxylabs
- 14. bit.ly/scalableapps pranny @ gmail.com