Google App Engine for Developers

Google App EngineGetting started…for Java developers@LynnLangit

New Course Preview – Google App Engine for Developers

@LynnLangitwww.lynnlangit.com

www.TeachingKidsProgramming.org

• 4 day class ‘Intro to GAE’ • Course in Java• www.Develop.com• On Site or at DevelopMentor

• New Developer User Group for GAE• first meeting at DevelopMentor in LA • Monthly – first meeting March 20

Full Course Objectives

• Understanding GAE– Setup for development with GAE– Creating first simple site with IDE templates – Simple deployment

• Understanding Google’s Cloud Storage Options– Non-relational, relational and more…

• Using Google Cloud Storage • Using Google Relational Cloud Storage• Using Authentication• Understanding other APIs• Deploying• Next Steps

What is Google App Engine? Why use it?• What

– Google’s cloud hosting and storage environment– Java or Python are supported– NoSQL (High-Replication Datastore) and/or mySQL

supported

• Why– Easy and free to try it out– Interesting feature set

• Automatic compute scaling• Flexibility on data storage / queries• Authentication choices • Access to other Google APIs

GAE APIs core and more…

Download and Configure Eclipse for GAE

• Download Eclipse• Get GAE SDK (access

to APIs)• Get GAE plug-in for

Eclipse

Configure Eclipse for GAE - options

• Enable other available APIs, partial list shown below• Use the GWT (Google Web Toolkit)

GAE Setup in Eclipse

• GAE SDK• GAE Eclipse plug-in• GAE developer

account– 5 GB storage free

Hello (Google) World – first application

Viewing Deployed Applications

• Create up to 10 applications• Click application to view detailed information about

each instance

Managing your application

Version Control

• Updating current versions• Using appcfg

Google App Engine – 2. Storage Options

Getting started…for developers@LynnLangit

Default data storage location – noSQL -- Datastore

Two types of Datastores I – About High-Replication

• Data is replicated across multiple data centers– using a system based on the Paxos algorithm– in synch, multi-master

• Provides the highest level of availability for reads and writes (99.999% SLA)– at the cost of higher latency on writes due to the

propagation of data (2x slower on write than other datastore type [master/slave])

– Results in most queries being eventually consistent*

• Reads from ‘fastest source’ (usually local)• Reads are transactional

Two types of Datastores II – About Master/Slave

• Data written to a single master data center is replicated async to all other (slave) data centers

• Offers strong consistency for all reads and queries• Results in periods of temporary unavailability

during data center issues or planned downtime (99.9% SLA)

• Reads from master only

Create your Application

• Select the storage options >>>

Configure your GAE Application for Data Storage

• Configure the data storage in Eclipse– HR Datastore (default) -- noSQL

• JDO/JPA (optional)• JDBC/nHibernate not supported

– Cloud mySQL (optional) -- RDBMS• Use local mySQL instance for testing

– Can also use Developer Storage -- buckets

HR Datastore put and get (asList)…from Ikai’s blog

Transactional Put..another example from Ikai

Viewing GAE storage

Cloud Data Storage Options for GAE

NoSQLRDBMS

Other

Cloud Data Storage Options for GAEType Name Notes

noSQL Datastore – High Replication

Default (Data, Blobs. Queues)

noSQL Datastore – Master/Slave For highest consistency

noSQL Developer Storage Beta (Experimental)

RSDBMS mySQL Beta - RDBMS

Graph Freebase Beta

MapReduce Big Query Beta (Invite only)

Other Full-text indexing Beta (Invite only)

Document-based

None available n/a

www.TeachingKidsProgramming.org

• Do a Recipe Teach a Kid (Ages 10 ++) free courses

• Teach or Donate

New Course Preview – Google App Engine for Developers

@LynnLangitwww.lynnlangit.com

www.TeachingKidsProgramming.org

• 4 day class ‘Intro to GAE’ • Course in Java• www.Develop.com• On Site or at DevelopMentor

• New Developer User Group for GAE• first meeting at DevelopMentor in LA • Monthly – first meeting March 20