Introducing WCF :- Next-generation connected systems on Windows

Outline 

1.  Connected systems overview 
2.  The move towards "services" 
3.  Service-orientation 
4.  Introduction to WCF 
5.  WCF programming model basics 
6.  Common WCF questions 

1.What is a connected system? 

• An application that is distributed across multiple computer nodes  

Building connected systems on Windows 

• MS has shipped many communication frameworks over the years  

2.The move towards "services" 

• Demand for technology freedom and interoperability is common now  Services expose units of functionality via messaging Interop achieved via standard protocols and message formats
  

Service design philosophies 

SOAP + WS-* services 

•  The industry has defined a complete protocol stack for services Typically implemented with RPC-based toolkits, feels a lot like COM+.

RESTful services 

•  RESTful services typically embrace HTTP, the "Web" transport 
•  Services are modeled as "resources" with unique identifiers (URI's) 
•  HTTP defines a uniform service contract: GET, POST, PUT, DELETE (CRUD)
•  Resources can be represented as XML, RSS, JSON, etc
•  HTTP provides numerous features for security and scalability
•  A successful design pattern used throughout the Web today 

3. Service-orientation 

• Service-orientation is a design paradigm for separation of concerns 
•  Focused on autonomy, explicit boundaries, contracts & policies 
•  Design principles help achieve a Service Oriented Architecture (SOA) 
•  SOA says nothing about technology – room for both SOAP & REST 

      The ideal communication framework 

4. Introducing WCF 

       WCF is the new unified "communications" framework for Windows

Services and endpoints 

• With WCF, you write services that expose endpoints to the world
• Service implementation defines business logic
• Endpoints define the communication options
• Services can expose multiple endpoints for consumers

What is an endpoint? 

•  Endpoints tell WCF how to build the runtime communication channels

Consuming services with WCF 

• Clients need to know several things in order to consume a service 
• Where to send the message (address) 
• How to send the message, such as what transport/protocols to use (binding) 
• What the messages should contain (contract)

WCF clients 

• With WCF, you consume services via channels based on endpoints 
•  Clients retrieve endpoint definitions from service metadata 

Summary 

• WCF provides a unified model with flexibility in communications 
•  Your choice of architecture, transport, message format, protocols, etc 
•  Replaces the need for the preceding Windows frameworks 
•  There are several good reasons to begin moving towards WCF 
•  It provides a simpler model that will increase productivity/reach 
•  Microsoft has positioned it as the "DCOM" of the next decade