• is de-facto framework for distributed systems in .NET
• supports various message exchange patterns and formats
• is extensible and customizable

• Address
  • http://my.api.services.net/customers
  • net.tcp://super.service/contacts
• Binding
  • Transport protocol
  • Message enconding
  • Communication pattern
  • Reliability
  • Security
  • Transaction propagation
  • Interoperability
• Contract
  • Data contract
  • Operation contract

• BasicHttpBinding
• WSHttpBinding
• WSDualHttpBinding
• WSFederationHttpBinding
• MsmqIntegrationBinding
• NetNamedPipeBinding
• NetMsmqBinding
• NetPeerTcpBinding
• NetTcpBinding

• Out of the box tuned for all occasions
• Except performance!

• up to 100ms response time
• able to handle more than 2K req/sec over HTTP

• JSON (vs XML)

  http://www.json.org/

• Google Protocol Buffers (vs Binary)

  http://code.google.com/apis/protocolbuffers/

• Very fast, compact
• Getting popular fast too
• Several .NET implementations: protobuf-net, proto#, dotnet-protobufs
• NetTcp + ProtoBuf = Super Fast

Code available at: https://github.com/donatasm/WCF-Performance-Tuning

• DataContractSerializerOperationBehavior will not work with WebHttpBehavior
• http://stackoverflow.com/questions/1174486/what-could-be-the-reason-that-my-custom-rest-serializer-is-not-working
• http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/1578a7e8-94d3-478c-b86e-73d2ab07f2eb

• Prevents overloading of a service
• Default values are usually too strict

• PerCall
• PerSession
• Single

• MaxConcurrentCalls
  v3.0: 16, v4: 16*CoreCount
• MaxConcurrentSessions
  v3.0: 10, v4: 100*CoreCount
• MaxConcurrentInstances
  v3.0, v4: MaxCocurrentCalls+MaxConcurrentSessions

Code available at: https://github.com/donatasm/WCF-Performance-Tuning

• Every request is important
• No excuse for "Oh, timeout? Please try again, our system needs a warm up"

• WCF uses completion ports (IOCP) thread pool for request processing
• There is a 15 sec timeout for IOCP thread pool
• Thread pool takes time to create new threads for incoming requests
• Issue still not fixed in .NET 4

Code available at: https://github.com/donatasm/WCF-Performance-Tuning

• WCF service operations supports APM
• Should help on blocking operations: r/w file, network stream

Code available at: https://github.com/donatasm/WCF-Performance-Tuning

• Any more tips to add?
• Alternatives to WCF?
• Questions?