Google Technology User Group #4An Introduction to the Google App Engine

by George Holler

17 November 2010

The Google App Engine

ScalableScalable

CostCost

PlatformPlatform For building web apps in the cloud

Automatic scaling and load balancing

Pay for what is used, with limits you set

CodeCode In Python or Java

SDKSDK Local development environment

APIsAPIs Google APIs for web programming

Architecture

Sandbox – What you can do

Sandbox – What you can't do

APIs...

Datastore API Interface to save and retrieve data

Memcache API High performance in-memory key-value cache

Mail API Send and receive emails

URL Fetch API Access web resources

Users API Interface with Google Accounts

Images API Interface to manipulate images (jpg, png)

Blobstore API Interface for saving large binary data

XMPP API Interface for Instant Messaging

Task Queue API Interface to enqueue tasks for app (exp)

Namespaces API Multitenancy

OAuth API Third party authentication (exp)

Mapper API For MapReduce (exp)

Java API mapping

Google Datastore

Google Datastore

Google Datastore APIs

Google App Engine Dashboard

Google App Engine Dashboard

System Status

App Engine Hard Limits

Apps per developer 10

Time per request 30 sec

Blobstore size (Total file size per app) 2GB

HTTP request size 10 MB

HTTP response size 10 MB

Datastore item size 1 MB

Number of files (app and static files) 3000

Size of any static or app file 10 MB

Application code size 150 MB

Number of values in an index for an entity 5000

Number of entities returned in a query at a time 1000

Number of entities in a batch put or delete 500

App Engine Tools

Resources

GAE Dashboard: http://appengine.google.com

GAE Docs: http://code.google.com/appengine/docs/

System Status: http://code.google.com/status/appengine

My Blog:

http://georgeholler.wordpress.com

My Email: georgeholler @ gmail.com

ood Bye!