This document summarizes a presentation on using real-time web technologies like SignalR to broadcast music from Spotify to multiple users simultaneously. The presentation discusses challenges like scalability and synchronizing playback across clients. It proposes using Azure Services like Websites and Service Bus to host the real-time web application and help it scale. The goal is to demonstrate how these services can be used to build an interactive music sharing experience where all users' playback remains synchronized.

1. itcampro@ itcamp13# Premium conference on Microsoft technologies
Broadcasting Music from the
Cloud
Andy Cross
Windows Azure MVP
Elastacloud
@andybareweb
blog.elastacloud.com

2. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
CloudHuge thanks to our sponsors!

3. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• Real Time Web
• Social media is the new telephone
• Spotify API
• Synchronicity
• SignalR
• Windows Azure Websites
• Service Bus
• ROCK!!!
Agenda

4. itcampro@ itcamp13# Premium conference on Microsoft technologies
REAL TIME WEB
What is the
Any sufficiently advanced technology is
indistinguishable from magic.
Arthur C Clarke

5. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• A history!
– HTML
– Javascript
– Iframes
– XmlHttp
– AJAX
– JSONP
– Web Sockets
Real Time Web

6. itcampro@ itcamp13# Premium conference on Microsoft technologies
Facebooks’ Real Time Web
Facebook has multiple real time web features, such as the news
feed and messaging

7. itcampro@ itcamp13# Premium conference on Microsoft technologies
Twitters’ Real Time Web
Twitter is perhaps the ultimate in real time web opportunities, but
even it struggles with *n more tweets*

8. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• With great advantages
– Instant messaging
– Responsive user interfaces
– Collaboration and sharing
• Come some great problems
– Scalability
• Concurrent connections
• Server load
– Complexity of client
Real time web pitfalls

9. itcampro@ itcamp13# Premium conference on Microsoft technologies
SOCIAL MEDIA
If you want to share music, the 1990s were better than

10. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• Billions of users of facebook
• Imagine sharing music on there.
– READY. STEADY. GO!!!
• My real time is not your real time
• If we want to build engagement on
– Brand
– Concept
– Movement
• we must engage simultaneously
Social Media

11. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
CloudThe Real Time Web

12. itcampro@ itcamp13# Premium conference on Microsoft technologies
SPOTIFY
Broadcast Music to

13. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• Spotify is a 4 year old ‘start up’
– Streaming music
– Integrated apps
• Apps are written in HTML5 and JS
– Chromium Embedded
• Its API for apps gives every song a URI
– spotify:track:12345679abc
• We will distribute these URIs along with a
Play command
Spotify

14. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
function playTrack(data) {
console.log(data);
player.playTrack(models.Track.fromURI(data)).d
one(function ()
{
//this is a promise update the ui maybe
});
Example Spotify code

15. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• Introducing Goose
• Geese fly together.
• Geese fly in flocks.
• There is a lead goose in the flock
• The rest are tail geese.
• Geese honk
• Geese sing
• Geese flap
Using the Real Time Web to fix this

16. itcampro@ itcamp13# Premium conference on Microsoft technologies
SYNCHRONICITY?
But how do we achieve

17. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• We can send a Play command to individuals.
• How can we combine the Real Time Web
with this?
My real time is not your real time

18. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• We cannot just send PLAY commands
– What if we join part way through a song
– Nothing would be played until we completed the
song
• We also track the LEAD GOOSE’s position
My real time is not your real time

19. itcampro@ itcamp13# Premium conference on Microsoft technologies
ASP.NET SIGNALR
Technologies for the Real Time Web

20. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
CloudWhat does SignalR try to fix?
Here’s some data!

21. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
CloudHow does it fix it?
Yeah, dude!

22. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
CloudComponents

23. itcampro@ itcamp13# Premium conference on Microsoft technologies
WINDOWS AZURE WEBSITES
Scalable Hosting

24. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
Cloud
• Start on Free
– And continue for dev/test
• Production uses Reserved Mode
– Custom URL
– Scalable as easily as:
Not a lightweight option

25. itcampro@ itcamp13# Premium conference on Microsoft technologies
SERVICE BUS BACKPLANE
SignalR scale out

26. itcampro@ itcamp13# Premium conference on Microsoft technologies
Private & Public
CloudScaling with the Service Bus

27. itcampro@ itcamp13# Premium conference on Microsoft technologies
ROCK! HONK!
Enough talk!

28. itcampro@ itcamp13# Premium conference on Microsoft technologies
Q & A