Programming WCF Services

Transaction Propagation

WCF can propagate transactions across the service boundary. This enables a service to participate in the client’s transaction, and for the client to include operations on multiple services in the same transaction. The client itself may or may not be a WCF service. Both the binding and the operation contract configuration control the decision whether or not the client transaction is propagated to the service. I call a transaction-aware binding any binding that is capable of propagating the client’s transaction to the service if configured to do so. Not all bindings are transaction-aware; only the TCP-, IPC- and WS-related bindings are transaction-aware (those would be the NetTcpBinding, the NetNamedPipeBinding, the WSHttpBinding, the WSDualHttpBinding and the WSFederationHttpBinding, respectively).

Transaction Flow and Binding

By default, transaction-aware bindings do not propagate transactions. The reason is that like most everything else in WCF, it is an opt-in setting. The service host or administrator has to explicitly give its consent to accepting incoming transactions, potentially from across the organization or the business boundaries. To propagate a transaction, you must explicitly enable it at the binding on both the service host and the client sides. All transaction-aware bindings offer the Boolean property TransactionFlow, such as:

public class NetTcpBinding : Binding,...
{
   public bool TransactionFlow
   {get;set;}
   //More members
}

TransactionFlow ...