WCF - One OperationContract sees Web.config, another doesn't

Question

I have a WCF service with two methods, Ping and PutAddress. Ping works fine, but PutAddress was failing to initialize NHibernate correctly. Narrowing down the issue, I realized that the relevant settings from Web.config were not being read by PutAddress.

Strangely, Ping does have access to the settings from Web.config. I removed all of the NHibernate code and boiled it down to just trying to read the settings. Ping is able to read the settings (returns non-null, values in result are correct) while PutAddress' result is null.

Again, NHibernate is now completely out of the picture. Both methods simply try to read the relevant settings from Web.config. Ping succeeds while PutAddress fails.

Any thoughts?

Interface:

[ServiceContract]
public interface IMyService
{

    [OperationContract]
    string Ping();

    [OperationContract]
    Address PutAddress(Address address);
}

Implementation:

public class MyService : IMyService
{
    public string Ping()
    {
        NHibernate.Cfg.ConfigurationSchema.HibernateConfiguration result = 
           (NHibernate.Cfg.ConfigurationSchema.HibernateConfiguration)
         System.Configuration.ConfigurationManager.GetSection("hibernate-configuration");
        if (result == null)
        {
            System.Diagnostics.Debugger.Break(); // Does NOT break, "Pong" returned 
        }

        return "Pong";
    }

    public Address PutAddress(Address address)
    {
        NHibernate.Cfg.ConfigurationSchema.HibernateConfiguration result =
           (NHibernate.Cfg.ConfigurationSchema.HibernateConfiguration)  
            System.Configuration.ConfigurationManager.GetSection("hibernate-configuration");
        if (result == null)
        {
            System.Diagnostics.Debugger.Break(); // Breaks, result is null
        }

        return address; // Return version potentially modified with DB-assigned ID
    }
}

EDIT:

Here is the (sanitized) Web.config

<?xml version="1.0"?>
<configuration>
  <configSections>
    <!-- NHibernate Section -->
    <section name="hibernate-configuration" type="NHibernate.Cfg.ConfigurationSectionHandler,NHibernate"/>
    <!-- Log4Net Section -->
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net"/>
  </configSections>
  <!-- NHibernate Configuration -->
  <hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
    <session-factory>
      <property name="dialect">
        NHibernate.Dialect.MySQLDialect
      </property>
      <property name="connection.provider">
        NHibernate.Connection.DriverConnectionProvider
      </property>
      <property name="connection.driver_class">
        NHibernate.Driver.MySqlDataDriver
      </property>
      <property name="connection.connection_string">
        Server=localhost;Database=DB;User ID=USER;Password=PASS
      </property>
      <property name="proxyfactory.factory_class">NHibernate.ByteCode.Castle.ProxyFactoryFactory, NHibernate.ByteCode.Castle</property>
      <property name="show_sql">true</property>
      <mapping assembly="MyService"/>
    </session-factory>
  </hibernate-configuration>
  <!-- Log4Net Configuration -->
  <log4net>
    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender, log4net">
      <layout type="log4net.Layout.PatternLayout, log4net">
        <param name="ConversionPattern" value="%d %p %m%n"/>
      </layout>
    </appender>
    <appender name="RollingFile" type="log4net.Appender.RollingFileAppender,log4net">
      <param name="File" value="log.txt"/>
      <param name="AppendToFile" value="true"/>
      <param name="DatePattern" value="yyyy.MM.dd"/>
      <layout type="log4net.Layout.PatternLayout,log4net">
        <conversionPattern value="%d %p %m%n"/>
      </layout>
    </appender>
    <root>
      <priority value="DEBUG"/>
      <appender-ref ref="ConsoleAppender"/>
    </root>
    <logger name="NHibernate" additivity="false">
      <level value="WARN"/>
      <appender-ref ref="RollingFile"/>
      <appender-ref ref="ConsoleAppender"/>
    </logger>
    <logger name="NHibernate.SQL" additivity="false">
      <level value="ALL"/>
      <appender-ref ref="RollingFile"/>
      <appender-ref ref="ConsoleAppender"/>
    </logger>
  </log4net>

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
  </system.web>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
          <serviceMetadata httpGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>
 <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
  </system.webServer>

</configuration>

Answer 1

I had an odd problem myself. I could not return "DataTable" objects from a WCF operation. I wonder if there could be a problem with returning an "Address" object from a WCF operation as well.

I don't know the complete answer to your question, but I would suggest the following

In your code for PutAddress, try replacing Address PutAddress(Address address); with string PutAddress(Address address); and replace return address; with return "Pong"

By doing so, you will ascertain the flow of execution through your code. Make sure that you are actually breaking and returning null as opposed to returning a null value of address.

If the new code returns null, then you are in fact having trouble reading from the file. I suspect that it will actually return "Pong", indicating that your code is returning Address, which somehow contains null because of WCF weirdness.

Answer 2

Found the problem - one call was from a Unit Test that I hand-coded, which uses MyServiceClient that was generated by Visual Studio when I added a Service Reference. The other call was from a unit test that was created by the Visual Studio (2010) Unit Test wizard, which just instantiated MyService as an object. The VS-generated unit test was running in-process as a result.