Exception "Transaction canceled" when creating a new TransactionScope ()

This is my first WCF both client and server. SQL Server 2008.

I am forced to use TransactionScope from my Windows Forms Application which is working as a client against WCF service. I haven't used this type of transaction before, usually using connection.BeginTransaction (), which I like because it's easier to keep track of what's going on.

I call a function (I hope these are nesting transactions), but one of my calls to create a new TransactionScope instance crashes with a "Transaction excluded" exception. The inner exception is null. I am assuming the transaction came back before this, but I have no idea how to track if an ambient transaction was done and what the status was.

example client (not real code. I've verified that all funcs use scope.Commit ()) Any help on how to track down the issue please?

(Often I get error messages that the MSDTC service needs to be started, but I don’t understand why it is used when distributing with a single database / wcf service)

void Function1(AMessageObj m)
{
  using (var client = GetOpenWebClient())
    WriteMessage(m, client);
}

void WriteMessage(AMessage m, OpenWebClient client)
{
  using (var scope = new TransactionScope())
  {
    var audit = GetSomeAuditInfo(AMessage.UserId, client);
    WriteTheMessage(AMessage, client);
    WriteAudit(audit, client);
    client.SetTime(DateTime.Now);
    scope.Commit();
  }  
}

AuditRecord GetSomeAuditInfo(Int userId, OpenWebClient client)
{
  var result = client.ReadAuditRecord(userId);
  return AuditRecord.FromWeb(result);
}

void WriteTheMessage(AMessage msg, OpenWebClient client)
{
  using (var scope = new TransactionScope())
  {
    client.WriteTheMessage(msg.ToWeb());
    scope.Commit();
  }
}

void WriteAudit(AuditRecord audit, OpenWebClient client)
{
  using (var scope = new TransactionScope())
  {
    client.WriteAudit(audit.ToWeb());
    scope.Commit();
  }
}

      

        
        
        
      

    

example WCF service

[ServiceContract]
interface IService
{
  [OperationContract]
  void WriteTheMessage(WebRecord message);

  [OperationContract]
  WebRecord ReadAuditRecord(int userId);

  [OperationContract]
  void WriteAudit(WebRecord audit);
}

class MyWebService : IService
{
  [OperationBehavior(TransactionScopeRequired = true)]
  void IService.WriteTheMessage(WebRecord record)
  {
    using (var connection = GetOpenConnection())
    {
      dowritethings;
    }
  }

  [OperationBehavior(TransactionScopeRequired = false)]
  WebRecord IService.ReadAuditRecord(WebRecord record)
  {
    using (var connection = GetOpenConnection())
    {
      return readthings;
    }
  }

  [OperationBehavior(TransactionScopeRequired = true)]
  void IService.WriteAudit(WebRecord record)
  {
    using (var connection = GetOpenConnection())
    {
      dowritethings;
    }
  }
}