Google App Engine introduction as presented by Kayode Odeyemi of Opevel Nigeria.

1. GOOGLE APP ENGINE FOR THE
ENTERPRISE
Kayode Odeyemi
Cloud Camp 2011
May 28th, 2011

2. The Cloud
1. Convenience
Pay for what you use
2. On-Demand network access
Use as much as you need, whenever you need
3. Minimal management effort
Don’t have to build your own infrastructure

3. Cloud Computing – As seen by Gartner

4. WHAT IS GOOGLE APP ENGINE?
• Google’s own infrastructure for running web applications
• The P (Platform) of Cloud Computing.
• App Engine is HTTP Server, but does not serve HTML
• Host web services for integration
• Consume other web services
• Various authentication options: Oauth, Google Account
So, Google App Engine falls under PaaS of Cloud Computing

5. WHY GOOGLE APP ENGINE?
• Easy to build
• Easy to maintain
• Easy to Scale

6. HOW DOES IT WORK?
• Build
• Push
• Never worry about scalability

7. HOW DOES IT WORK?
• Build
– Download SDK
– Of Java, Python or GO Runtime
– Build with dev tools such as GPE (Eclipse plugin), Netbeans,
AppLauncher

8. HOW DOES IT WORK?
• Push
– Deploy easily with simple commands
./appengine-java-sdk/bin/appcfg.sh update myapp/war
– Administer in Administration console (App Engine
Dashboard)

9. HOW DOES IT WORK?
• Scalability
– Automatic performance improvements as traffic on your
app increases
See more in GAE Dashboard
– Automatic instance creation to handle load as well as
distribution of resources
CPU, Bandwidth, Quota, Memory
– Fault Tolerance

10. PERFORMANCE & SCALABILITY
• Built with scalability as top priority
• Memcache
– Distributed RAM cache
– Heavily dependent on mecache size allocated. The more the merrier

11. INTEGRATION
Authenticati Google Google
on
OpenSocial XMPP
Apps Data APIs
Facebook GEO YouTube
Django AJAX
API (Maps) API

12. APPLICATION ENVIRONMENT – BUILDING BLOCKS
• Java Runtime
• Python Runtime
• GO Runtime
• Datastore
• Suite of APIs to do common stuffs
– URL Fetch
– Mail
– Memcache
– Image Manipulation
– Channel
– Blobstore

13. APPLICATION ENVIRONMENT – BUILDING BLOCKS
JAVA
Same technologies / APIs you are used to

14. KNOW HOW YOUR APP IS DOING – PLATFORM MANAGEMENT
PYTHON
• Communicates via CGI protocol
• Supports Django
• Supports Python 2.5+
Datastore Memcache URL Fetch Mail Blobstore
CGI CGI CGI CGI CGI
Google App Engine

15. DATASTORE – OBJECT PERSISTENCE
• Built on BigTable
• Non-relational database management system
• Consistent read and write even in a distributed network
Storage 2
Storage 1 Storage 3

16. ADMINISTERING YOUR APP – The Admin Console
• Create a new application
• View request and error logs and analyze traffic
• Browse your application's datastore and manage indexes
• Administer your datastore
• View your application's instances
• Manage task queues, allowing for viewing, deleting or running individual tasks
immediately
• Test new versions of your application and switch the version that your users see

17. ADMINISTERING YOUR DATASTORE

18. URL Fetch
• Consume external resources with your app
• Supports HTTP & HTTPS
String message = URLEncoder.encode("my message", "UTF-8");
try {
URL url = new
URL("http://www.example.com/comment");
HttpURLConnection connection =
(HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");

19. URL Fetch – Write and return response to client
OutputStreamWriter writer = new
OutputStreamWriter(connection.getOutputStream());
writer.write("message=" + message);
writer.close();
if (connection.getResponseCode() ==
HttpURLConnection.HTTP_OK) {
// OK
} else {
// Server returned HTTP error code.
}
} catch (MalformedURLException e) {
// ...
} catch (IOException e) {
// ...
}
Note: Not all java.io classes are supported in app engine. Check whitelisted JRE
classes

20. Mail
• Send mail using JavaMail or Low level API
try {
Message msg = new MimeMessage(session);
msg.setFrom(new
InternetAddress("admin@example.com", "Example.com Admin"));
msg.addRecipient(Message.RecipientType.TO,
new
InternetAddress("user@example.com", "Mr. User"));
msg.setSubject("Your Example.com account has been
activated");
msg.setText(msgBody);
Transport.send(msg);
} catch (AddressException e) {
// ...
} catch (MessagingException e) {

21. Memcache
• Distributed in-memory data-cache
• Improve performance
• You don’t have to always persist storage in datastore. Some stuffs can be
stored in-memory
// A reference to the cache service
private final Cache cache = new Cache(MemcacheServiceFactory
.getMemcacheService());

22. Channel API
• Communicate between your application and Google Servers
asynchronously.
• Very useful to chat room apps, collaborative apps

23. Blobstore
• Serve large data objects
• Insert / Retrieve / Edit, in bulk
• Flexible
– Direct access to blob data in memory
• Fast access to blob data
– 5MB in ~ 2s
// Simple servlet to create the actual upload url
String uploadurl =
blobstoreservice.createUploadUrl(“/Upload”);
// Called after upload
Map<String, Blobkey> blobkeys =
blobstoreservice.getUploadedBlobs(req);

24. Google App Engine for Business
• Enterprise Application Management
– Centralized domain console
• Enterprise reliability and support
– 99.9% Service Level Agreement
– Enterprise support
• Hosted SQL
– Relational SQL database in the cloud
• SSL on your domain
• Extremely secure by default
– Integrated Single Sign-on
• Pricing that makes sense
– Apps cost $8 per user, up to $1000 max per month (Pre-IO2011 Pricing)

25. ONLINE REFERENCES
Get Started with App Engine
http://code.google.com/appengine
Get the SDK and build cool stuffs
http://code.google.com/appengine/downloads.html
Google Apps for Business
http://code.google.com/appengine/business/
BigTable
http://labs.google.com/papers/bigtable.html
Google I/O 2011
http://www.google.com/events/io/2011/index-live.html
Introduction to Google Cloud Platform Technologies by Chris Schalk – Google Developer Advocate
http://goo.gl/zmxvF
Sample projects
http://goo.gl/djgMS

26. Questions
• Website - http://opevel.com
• Twitter : @opevel @googledevtools #gwt @charyorde
• Opevel Services
– Google App Deployment
– Custom Application Development on Google App Engine
– Integration services with legacy systems