Google App Engine is Google's Platform as a Service that allows users to run scalable web applications on Google's infrastructure. Written in Java or Python, apps run in a managed sandbox and use Google's non-relational Datastore and other services. Key features include automatic scaling, high availability, easy setup, and a free usage tier.

1. Google App Engine Java style Peter Sönnergren Lind GTUG Stockholm 2010-01-14

2. whoami Java dev since like 1999 Ruby enthusiast Consultant @ Devoteam Quaint Owner and CTO @ Pockus A book club that doesn't suck http://www.pockus.se

3. App Engine 101 Googles Cloud offering Run your web apps on Google's infrastructure Platform As A Service Unique Selling Point - Scalability on demand Instances are added when needed Two flavors Python since spring 2008 Java since spring 2009 Technology preview :S

4. The first hit is always free App quotas Free to start, 5 million pageviews/month 10 apps per user Can enable billing AdWords payment model $32 worth of resources/month http://yourapp.appspot.com http://www.yourapp.com using Google Apps for Domains

5. GAE/J in a nutshell A place to run Java Servlets (2.5 API) Meaning support for Servlets/JSP Web Frameworks (Spring MVC/Wicket/Tapestry/Struts ...) In a sandbox All apps in isolation Subset of the JRE Jetty customized Don't use the Jetty features, this might change

6. Limitations JRE White List No threads Cron jobs Task queues No outgoing connections (except mail/http/xmpp) Read-only FS 30 second request limit, no push (upcoming?) App spin-up time No SLA available

7. Datastore - BigTable NoSQL Stores “entities” Parent-Child relationships Add “properties” at will (beware of restrictions in queries) GQL to query Transactions – but not global like in databases != for one column only Max number of entities returned is 1000

8. Services – using standard APIs Datastore (BigTable) JDO JPA Memcache – javax.cache URL Fetch – java.net Mail – javax.mail Low-level APIs are available

9. Services – Google APIs Google Accounts XMPP Image manipulation Task Queues Blobstore Cron jobs

10. Teh awesome Scalability is job #1 On demand Easy to get started No sysadm work needed An App Engine app is built to scale No long running requests NoSQL Move processing out of persistence layer

11. Getting started Sign up using phone nr (for verification sms) Create app id Download Eclipse plugin Or use SDK with scripts Generate app Push to cloud

12. Development dev_appserver.sh User service Datastore Et al, but no cron or tasks Generates indexes for Datastore Blacklist/whitelist emulation Eclipse plugin (official) Netbeans, IntelliJ Support for mocking the environment for testing

13. Administration https://appengine.google.com One app can have several developers Concurrent versions http://<version>.latest.appspot.com Manage billing settings Bandwidth/CPU time/storage/mail Logs Datastore viewer

14. Language support App Engine accepts Java byte code, not source code Permissive with reflection magic, creating classloaders etc App Engine team works together with JVM Lang implementors http://lotrepls.appspot.com/ beanshell, clojure, groovy, javascript, jython, jruby, scala, scheme PHP through Caucho/Quercus

15. Vendor lock-in? Use standard Java APIs Demoed on IBM Websphere http://code.google.com/p/appscale/ http://code.google.com/p/typhoonae/ Python only http://arachnid.github.com/bdbdatastore/ Use dev_appserver with alternative datastore

16. Demo Your first cloud application in a few minutes!

17. Resources http://code.google.com/appengine/ http://googleappengine.blogspot.com/ Programming Google App Engine On O'Reilly Written by a Googler Google Groups http://code.google.com/appengine/community.html

18. Contact mailto:peter@lind.be http://github.com/peterlind http://twitter.com/peter_lind