MIX11 - Session Review - Building Windows Phone 7 Applications with the Windows Azure Platform

Wade Wegner ( Technical Evangelist @ Windows Azure Team )

Why Phone + Cloud?

  • The cloud levels the playing field
  • The cloud provides larger pool of resources from which to pull
  • The cloud provides a way to reach across device platforms

Why Windows Phone 7 and Windows Azure?

  • Because Windows Azure is PaaS. you build, Windows Azure runs it
  • Automatic OS patching
  • Scalable
  • Utility billing model
  • Additional services
    • Access Control Services (Provides Identity Federations)
    • Traffic Manager (Provides an easy way to manage the location from which Data Center the app is served)
    • Caching ( Provides a Caching Service that allows us to easily create cache in our apps)
    • CDN (Content Delivery Network)
    • …
  • Common Development tools
    • Visual Studio
    • Languages
    • Emulators for development
  • Demo Source Code: http://www.wadewegner.com/

What was shown in the Demo

  • Identity
    • Identity Options
      • Create your own (eg. username + password, token, …)
        • Custom Model
        • ASP.NET Membership Providers
      • Use a single existing identity system (eg. Live Id, Facebook, Twitter, …)
      • Outsource identity management (eg. Access Control Service)
      • More information about this:
        • Authenticating Users in a Windows Phone 7 App via ACS, OData and Windows Azure - http://bit.ly/wp7acs
  • Storage
    • Storage Options
      • SQL Azure
        • Relational Database
        • Highly available
        • Managed for you as a Service
        • Pattern
          • WebRole that exposes an OData Service
            • Create a Web role with an OData Service that will expose your SQL Azure data to your clients
      • Windows Azure Tables
        • Non-relational structured Storage
        • Massive scale-out
        • OData
        • Pattern
          • Using Public Blobs
            • Client sends data to the Web Role
            • Web Role stores data in blobs
            • Client fetches public blobs directly
          • Shared Access Signatures (SAS)
            • Client gets Shared Access Signature from the Web Role
            • Client inserts the SAS in the URI and stores data in blobs
            • Client fetches public blobs and even private containers as long as the SAS allows it
      • Windows Azure Blobs
        • Big files
        • REST
        • Pattern:
          • Proxy Calls
            • Client sends data to the Web role
            • Web role stores data in Blobs
  • Services
    • Web Role vs Worker Role
    • Web Role has IIS
    • Worker role does not
      • think about it as being a DLL with a Main()
    • Both implement the RoleEntryPoint
    • Scaling Work in Windows Azure
      • Traditionally
        1. Web role receives message
        2. Web role enqueues work
        3. Worker role pools queue
        4. Worker role sends notifications
        • Interesting because it splits the IIS and Services parts allowing you to scale them independently
    • Multitenancy
      • You can have more than one application running in your role instance
      • based on the Sites tag in the ServiceDefinition.csdef
    • Content Delivery Network (CDN)
      • Currently at least 24 nodes that will cache data locally in order to provide the data faster
    • Traffic Manager
      • Intelligently routes the request to the most appropriate Data Center according to the policies defined in it
  • Communications
    • Two primary communication models
      • Phone-initiated
        • Options
          • Http-based, request/response
          • Can be based on pooling of User Initiated requests
          • Frameworks choises (WCF, OData, WebRequest, …)
          • Wire Formats (SOAP, JSON, POX, …)
      • Cloud-initiated
        • Push Notifications
          • Single connection between phone and Microsoft Push Notification Service
            • The cloud cannot connect directly to the phone, just passing by the Microsoft Push Notification
          • There’s no warranty of delivery
          • Bandwidth and battery friendly
        • There kinds of push notifications
          • Raw – send a message to an app
          • Toast – send a message to the user
            • Blue bar at the top
          • Tile – Update an image, title or count
        • How does this works?
          1. Phone opens a channel in the Microsoft Push Notifications Service
          2. Phone sends the URL to the cloud
          3. Cloud pushes notifications via URL
          4. Microsoft Push Notification Service notifies the phone

Important Best Practice: DO NOT STORE SECRETS ON YOUR PHONE

What is there to make this easier?

  • Announcing: Windows Azure Toolkit for Windows Phone 7 (v1.1.0)
  • Make it easier for phone developers to use Windows Azure
  • Toolkit includes:
    • Client libraries
    • Sample apps
    • Source code
    • Documentations
  • Available on http://watoolkitwp7.codeplex.com
  • The phone will only communicate with a Service over HTTPs if
    • The cert is installed on the device
    • The cert is signed by a Trusted Authority
  • In order to use the self signed certs you need to install it on the phone

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