Question

This is a similar question as this one:
Win32Exception @ ServiceHost.Open() for WCF service.

I have a machine that is very slow on the ServiceHost.Open call below. It consistently takes 7 seconds or so to open the service, every time. This machine is my home box, and it is not part of a domain.

I can run the same code on another box (my work box) which is part of a domain and the service host opens in about 3-4 seconds on the first call, but if I run the program again the service host opens in about 1 second or less.

I have worked with MS support on this, and we generated trace logs and the part it’s hanging in is where is goes out and tries to connect to a domain, even on the machine that isn’t part of a domain. And it gets the “The specified domain either does not exist or could not be contacted.” exception in the trace log, and that’s where all the time is getting eaten up.

But what’s really weird is that even on my work machine, if I’m not connected to a domain (like if I’m not on my work network and just running from home) I still don’t get the delay.

I rebuilt my machine using Windows 7 64-bit, and the same behavior occurs (was running XP SP3, which I restored when Windows 7 didn’t seem to fix the problem).

I just wondered if anyone had any ideas of what could cause this. By the way, if I disable “Client for microsoft networks”, the time is like 4 seconds to open the ServiceHost, but that’s still not as fast as this machine used to be able to open the service. Somehow, it thinks it’s supposed to be part of a domain or something.

    static void RunServiceWithinEXE()
    {
        Uri baseAddress = new Uri("http://localhost:11111/Demo");
        ServiceHost serviceHost = new ServiceHost(typeof(CalculatorService), baseAddress);

        try
        {
            // Add a service endpoint
            serviceHost.AddServiceEndpoint(
                typeof(ICalculator),
                new WSHttpBinding(),
                "CalculatorService");

            // Enable metadata exchange
            ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
            smb.HttpGetEnabled = true;
            serviceHost.Description.Behaviors.Add(smb);
            serviceHost.Opening += new EventHandler(serviceHost_Opening);
            serviceHost.Opened += new EventHandler(serviceHost_Opened);
            serviceHost.Open();
            Console.WriteLine("The service is ready.");

            // Close the ServiceHostBase to shutdown the service.
            serviceHost.Close();
        }
        catch (CommunicationException ce)
        {
            Console.WriteLine("An exception occured: {0}", ce.Message);
            serviceHost.Abort();
        }
    }

    static void serviceHost_Opened(object sender, EventArgs e)
    {
        TimeSpan timeToOpen = DateTime.Now - shOpening;
        Console.WriteLine("Time To Open: :" + timeToOpen.Seconds);
    }

    static void serviceHost_Opening(object sender, EventArgs e)
    {
        shOpening = DateTime.Now;
    }

Here is my app.config, but I don’t have any special security configuration settings for the service in there, only some diagnostic settings to enable the WCF trace.

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <system.serviceModel>
        <diagnostics>
            <messageLogging maxMessagesToLog="30000"
                    logEntireMessage="true"
                    logMessagesAtServiceLevel="false"
                    logMalformedMessages="true"
                    logMessagesAtTransportLevel="true">
                <filters>
                    <clear/>
                </filters>
            </messageLogging>
        </diagnostics>
    </system.serviceModel>

    <system.diagnostics>
        <sources>
            <source name="System.ServiceModel" switchValue="Warning, ActivityTracing" propagateActivity="true" >
                <listeners>
                    <add name="xml" />
                </listeners>
            </source>
            <source name="System.ServiceModel.MessageLogging" switchValue="Warning">
                <listeners>
                    <add name="xml" />
                </listeners>
            </source>
        </sources>
        <sharedListeners>
            <add name="xml" type="System.Diagnostics.XmlWriterTraceListener" initializeData="C:\Temp\Server.svclog" />
        </sharedListeners>
        <trace autoflush="true" indentsize="4">
            <listeners>
                <remove name="Default" />
                <add name="ScottsConsoleListener" type="System.Diagnostics.ConsoleTraceListener" />
                <add name="ScottsTextListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="C:\Temp\DebugLog.txt" />
            </listeners>
        </trace>
    </system.diagnostics>
</configuration>

Note also that my service definition has SessionMode required (see below). If I take the SessionMode requirement out, I don’t get the delays.

using System;
using System.ServiceModel;
using System.ServiceModel.Description;

namespace Microsoft.ServiceModel.Samples
{
    // Define a service contract.
    [ServiceContract(Namespace = "http://Microsoft.ServiceModel.Samples", SessionMode = SessionMode.Required)]
    public interface ICalculator
    {
        [OperationContract]
        double Add(double n1, double n2);

        [OperationContract]
        double Subtract(double n1, double n2);

        [OperationContract]
        double Multiply(double n1, double n2);

        [OperationContract]
        double Divide(double n1, double n2);

        [OperationContract]
        string PrintName(string firstName, string lastName);

        [OperationContract]
        Point MakePoint(double x, double y);

    }
}

Answer 1

It turns out that if I disable netbios on my network connections, I don’t get the delays on the ServiceHost.Open calls. I am not sure why, but this seemed to fix the problem.

What’s weird is that when I did a clean install of XP, I didn’t have the delays even with the Netbios enabled, so I have no idea why it happens with my existing installation (I did the clean install on this same machine, and then restored my backup from an image to run these tests).