This document outlines a presentation on Google's Go programming language and Google App Engine. The agenda includes an introduction to Go, discussing features like concurrency and garbage collection. It also covers using Go with App Engine, including storing data, using services like Channels and Mail, and includes a demo of a fully functional Go app on App Engine.

1. Google’s Go Language for
Cloud Computing
Presented By:
Suby Gopalan
Yashashwini Adiga
Hem Singh Chouhan
Niranjan Singh
Piyush Mishra

2. Agenda of the Session
All about ‘GO’
Google App Engine
App Engine Modules
Storing data in Go
Go Service APIs
A fully functional Go App covered via
Demo

3. Subjective Analysis
Flaws in the existing languages like C++, Java

4. All about ‘GO’
Why one more programming language ?
Is ‘GO’ an object-oriented language?
Why do garbage collection? Won't it be too
expensive?
Why is the syntax so different from C?
Why is there no pointer arithmetic?

5. Features of ‘GO’ at a glance
Concurreny and Garbage collection
Has pointers but no pointer arithmatic
Support for networked and multicore
programming
Very fast
Semicolons are not used

6. Google App Engine
Platform as a Service
Tools you know and Love
Used by millions
Build and Deploy
Scale

7. Overview of App Engine Features
General Availability
Preview
Experimental
Third Party

8. Google App Engine for Go
Introduction
Selecting the Go runtime
Organizing Go apps
The sandbox
The Go SDK and tools

9. App Engine Modules in Go

10. .yaml files

11. Instance scaling and class
Manual, Basic, Automatic
Uploading modules
cd simple-sample
goapp deploy default/app.yaml
goapp deploy mobile-frontend/mobile-frontend.
yaml
goapp deploy static-backend/my-module.
yaml
Monitoring resource usage
Logging

13. Storing data in GO

15. Storing data in GO
Highly reliable and covered by the App
Engine SLA.
ACID transactions.
Advanced querying features.
High availability of reads and writes.
Strong consistency for reads and ancestor
queries.
Eventual consistency for all other queries

16. Google Cloud SQL
Is a web service that allows you to create,
configure, and use relational databases that
live in Google's cloud.
 It is a fully-managed service offering the
capabilities of a MySQL database, allowing
you to focus on application development.
Alternative Storage Solutions..
BLOBSTORE API Google Cloud Storage is
recommended over using the Blobstore API.

17. Go Service APIs

18. Go Service APIs and Capabilities
import "appengine/capability“

19. Important Players
CHANNEL
Javascript client
The server
Tokens

20. Life of a typical channel message
Interaction with Server

21. Interaction between clients

22. Tracking Client Connections
import "appengine/channel"
POSTs to /_ah/channel/connected/
POSTs to /_ah/channel/disconnected/

23. Examples of API
 Channel Go API - (channel.Create)
The Channel API creates a persistent connection
between your application and Google servers,
allowing your application to send messages to
JavaScript clients in real time without the use of
polling
 Images Go API
The Images Go API provides the ability to serve
images directly from Blobstore, and to optionally
resize or crop those images on the fly.
Image formats
Serving and re-sizing images from the Blobstore

24. Examples of API
 Logs Go API
Request Log, Application Log
 Mail Go API - import"appengine/mail“
App Engine applications can send email messages on
behalf of the app's administrators, and on behalf of
users with Google Accounts.
Apps can receive email at various addresses.
 Apps send messages using the Mail service and
receive messages in the form of HTTP requests
initiated by App Engine and posted to the app.

25. Examples of API
 Memcache Go API
– import appengine/memcache“
 NameSpace API
- The Namespaces API in Google App Engine makes it
easy to compartmentalize your Google App Engine
data. This API is implemented via the ,
appengine.Namespacefunction and is incorporated
in certain namespace-enabled APIs.

26. OAuth for GO
 OAuth is a protocol that allows a user to grant a third party limited
permission to access a web application on her behalf, without sharing
her credentials (username and password) with the third party.
 To initiate the authorization process on behalf of a user, a consumer
calls an OAuth endpoint to get a request token(Valid for 10 mins)
 Once the consumer has a request token, it must direct the user to sign
in using Google Accounts and authorize the consumer to access the
service provider on her behalf.
 Once authorized, the consumer calls the service provider to get
an access token
 The consumer includes this token with all requests to the application's
web service endpoints.

27. Users GO API
import"appengine/user"
package user provides a client for app
engine's user authentication service.
user represents a user of the application.
func (*User) String
String returns a displayable name for the user

28. XMPP GO API
 An App Engine application can send and receive chat messages to and
from any XMPP-compatible chat messaging service, such as Google Talk.
 An app can send and receive chat messages, send chat invites, request a
user's chat presence and status, and provide a chat status. Incoming XMPP
messages are handled by request handlers, similar to web requests.
 Sending chat messages
 /_AH/XMPP/MESSAGE/CHAT/
 Receiving chat messages
 app engine makes an http post request to the following url path when
your app receives a chat
 -MESSAGE:/_AH/XMPP/MESSAGE/CHAT/
 -to handle incoming messages, you simply create a request handler that
accepts post requests at this url path.

29. Handling User Presence
Enabling the xmpp_presence inbound service allows your
application to detect changes to a user's chat presence. When you
enable xmpp_presence, your application receives posts to the
following URL paths:
-Posts to /_ah/xmpp/presence/available/ signal that the user is
available and provide the user's chat status.
-Posts to /_ah/xmpp/presence/unavailable/ signal that the user is
unavailable.
-Posts to /_ah/xmpp/presence/probe/ request a user's current
presence.

30. Other Important Parts of Go
Configuration
Tools

31. DEMO