Windows Server

WCF and EPiServer: Using WCF Web Programming Model Services in EPiServer sites on IIS 7

Stephen Horsfield — Thu, 20 Nov 2008 17:10:58 GMT

I've just managed to get the .NET 3.5 style of WCF Web Programming Model services to work inside an EPiServer 5 R2 site on IIS 7 and Windows 2008. I had a few difficulties finding out how to integrate the new model into IIS/ASP.NET and then further problems getting it working in EPiServer. Here, I outline the solution.

Context

I'm currently designing a site that will be using the Akamai Edge Suite of technologies (www.akamai.com) and so I desire that all client access is through the caching layer. Additionally, I'm motivated towards a REST model for web services to support a greater degree of caching.

The new WCF Web Programming Model is ideal for this purpose as I can wrap service parameters directly into the URL and reduce the coding effort considerably. I had been concerned about the integration of services into the same website as EPiServer because of how the URL mapping works in the Web Programming Model.

Solution

The solution is really easy once you realise that the typical EPiServer installation changes the default ASP.NET configuration. Specifically, you may need the following:

Create a new folder to host your services
Create a small web.config in this folder (or use location tags in the main web.config file) and add service handlers
Create a ".svc" file for the service
Create the supporting .NET service code

Create a new folder to host your services

This is necessary to allow a separate application configuration. You can change the main application configuration at your own risk, however :)

For the purposes of this post, I'll use "~/services/".

Create a small web.config for this folder and add service handlers

You'll need to add the following:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="svc-ISAPI" path="*.svc" verb="*" modules="IsapiModule" 
           scriptProcessor="%SystemRoot%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll"
           resourceType="Unspecified" 
           preCondition="classicMode,runtimeVersionv2.0,bitness32" />
      <add name="ServiceHost" path="*.svc" verb="*"
           type="System.ServiceModel.Activation.HttpHandler, System.ServiceModel,
                 Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
           resourceType="Unspecified" preCondition="integratedMode" />
    </handlers>
  </system.webServer>
</configuration>

Now I took this from a cleanly created website with no configuration (using the IIS management console) and I recommend that you do the same.

Create a ".svc" file for the service

This file is created in the service folder and forms part of the URL so name it accordingly. I'll just use "service.svc" for illustration:

<%@ ServiceHost Language="C#" Service="Service" CodeBehind="~/App_Code/service.cs"
    Factory="System.ServiceModel.Activation.WebServiceHostFactory" %>

You should name your services more appropriately, of course.

Create the supporting .NET service code

So, you need to create the classes. Here, I'm using a simple file in the App_Code folder, but you might prefer to use a separate code project and assembly. Here's a simple example:

using System.ServiceModel;
using System.ServiceModel.Web;

[ServiceContract]
public interface IService
{
  [OperationContract]
  [WebGet(UriTemplate = "test?s={s}")]
  string test(string s);
}

public class Service : IService
{
  public string test(string s)
  {
    return "test: " + s;
  }
}

So, this is a very basic service with a single HTTP GET method that returns some data dependent on a single query string parameter. A perfect REST example as the result is defined by the input, there is no change of state (so two identical GET requests result in the same value) and so the response is suitable for caching.

Using the service

So now, you can access the service as http://your_episerver_site/services/service.svc/test?s=YourTestString. ASP.NET integration (and IIS) requires the use of a service extension, in this case ".svc", however this article may help you to remove this issue: http://blogs.msdn.com/bags/archive/2008/08/22/rest-in-wcf-part-ix-controlling-the-uri.aspx but don't forget that EPiServer already does some URL rewriting and so you'll have to make sure they don't conflict!

Metadata

Categories: ASP.NET, EPiServer, SOA, WCF, .NET, Windows Server
Keywords: Web Programming Model, Windows Communication Foundation, Service Oriented Architecture, AJAX, JSON
Technorati Tags: software development, Windows Communication Foundation, .NET, JSON, WCF, SOA, service design, Service Oriented Architecture, EPiServer, ASP.NET, AJAX

Virtual Server: "could not initialize the emulated Ethernet controller"

Stephen Horsfield — Mon, 21 Apr 2008 10:14:00 GMT

Overview

Recently, I began having problems with Virtual Server 2005 R2 on my Windows XP computer. I was not aware of anything having changed, except suddenly my VPCs couldn't find a network adapter. Facing the possibility of a complete laptop rebuild, I was scouring the net for a solution...

Failed attempts

Before finally landing a working solution, I attempted the following:

Restarting Virtual Machines (before and after other changes)
Restarting Virtual Server (and associated services)
Looking for patches (none applicable)
Creating new network configurations
Using alternative network connections

None of these helped. I also found various forum articles suggesting I reinstalled my network drivers, but I didn't want to do this unless I really had to. Finally, I found a solution that worked...

A solution

The following worked well:

Uninstall the Virtual Machine Network Service (in network connection properties), not just deselecting it
Restart Virtual Machine Helper and Virtual Server services
Reinstall the Virtual Machine Network service (in network connection properties) and select it for each connection
Restart Virtual Machine Helper and Virtual Server services again
Start a virtual machine and check

I won't promise it will work in all cases, but it helped me out!

References

Versions

Windows XP Professional with Service Pack 2
Windows Server 2003 (not verified)
Virtual Server 2005 R2 Enterprise Edition

Metadata

Categories: Virtual Server, IT Management, Windows XP, Windows Server
Additional keywords: missing network adapter, no network, network not working
Technorati Tags: Virtual Server, Networking

EPiServer: Problems importing data — POST fails

Stephen Horsfield — Fri, 18 Jan 2008 10:47:51 GMT

Overview

I've been importing a live EPiServer site into a development environment for further work. Normally, this works without problem, but this time I've been getting a POST error, but nothing informative. What's happening?

Solution

A quick look at the event logs on the IIS server quickly identifies the problem: the file exceeds the upload limit. Of course this is less likely to happen in a normal development run, but once there is a fair amount of data it fails. If I hadn't spotted the error in the event log, I might have been stuck for some time.

The default ASP.NET upload limit is 4 MB, so if you need more you will have to change the web.config settings. The element you have to change is the maxRequestLength attribute on the <system.web><httpRuntime> element. The size is specified in KB, so for a 32 MB limit, use the following:

<system.web> <httpruntime maxrequestlength="32768" /> </system.web>

References

<httpRuntime> Element (Microsoft MSDN)

Versions

Windows Server 2003
Windows XP
Microsoft .NET Framework 2.0

Metadata

Categories: Software Development, ASP.NET, IIS, EPiServer
Additional keywords: import, POST, error, upload limit
Technorati Tags: software development, IT Management, .NET, ASP.NET, EPiServer, import, problem

Windows: Having problems searching for text in files — not enough or any results...

Stephen Horsfield — Wed, 16 Jan 2008 16:29:26 GMT

Overview

Do you have problems searching for text in files using Windows XP, Windows Server 2003, Windows Vista or Windows Server 2008? This problem has been affecting us in our development environment, but how can you fix it?

Context

From Windows XP, Microsoft changed the default behaviour of the Windows Explorer search feature. They did this for performance reasons, and from Windows XP Service Pack 2 onwards you can choose to revert to the old behaviour, but the effect was that only certain file types are searched by default.

Solutions

There are two solutions:

Register a handler for the specific file types that you require. This can be completed by installing an indexing filter, such as a PDF filter from Adobe or a compressed files filter. See http://www.ifilter.org for various file type-specific filters
Enable search for all file types using a default handler for unregistered types

Installing a standard IFilter is as easy as running a setup application.

For the other options, the procedure is documented in this Microsoft article: Using the "A word or phrase in the file" search criterion may not work (Microsoft Support).

References

Using the "A word or phrase in the file" search criterion may not work (Microsoft Support)

Versions

Microsoft Windows Server 2003
Microsoft Windows XP

Metadata

Categories: IT Management, Windows XP, Windows Server 2003, Search
Additional keywords: Indexing service, IFilter, Indexing Filter, Keyword search, Full text search, bug, kbbug, missing results
Technorati Tags: IT Management, search, problem, Windows, Windows 2003, Windows XP, Indexing Service

Windows: Network folders do not refresh automatically in Windows Explorer

Stephen Horsfield — Tue, 08 Jan 2008 17:11:08 GMT

Overview

Sometimes you have to manually refresh folders in Windows XP to see changes that have taken place on network servers.

Context

When you create or delete any file in one or more network folders, you have to refresh the display to see the changes. This can happen with any folder, but most frequently when you are using Microsoft DFS technology.

Solution

You need to follow the instructions in File list in the Windows Explorer folder is not refreshed after you create, move, or delete files (Microsoft Support). This requires two things:

Install Windows XP Service Pack 2
Make a registry change as below:
1. Locate and then click the following key in the registry:
  HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
2. On the Edit menu, point to New, and then click DWORD Value.
3. Type NoSimpleNetIDList, and then press ENTER.
4. On the Edit menu, click Modify.
5. Type 1, and then click OK.

Note: These instructions are copied from the Microsoft article.

Versions

Microsoft Windows XP

Metadata

Categories: Windows XP, Windows Server 2003, IT Management, Windows Explorer
Additional Keywords: Network Shares, Folders, Missing Files, Bug, automatically refresh folders in Windows Explorer, network folders do not refresh
Technorati Tags: IT Management, Windows, Windows 2003, Windows XP, problem, networking, Windows Explorer, folder refresh, DFS

Windows: Disabling Data Execution Prevention

Stephen Horsfield — Tue, 08 Jan 2008 15:10:56 GMT

Overview

Sometimes, old code doesn't seem to work with the new Data Execution Prevention feature in Microsoft Windows. It's easy to turn it off for non-system applications and services, but how do you do it for system components, and why would you?

Warning: Data Execution Prevention is a security feature. Disabling DEP reduces the security of your system.

Context

On our Microsoft Commerce Server 2002 system, running on Windows Server 2003, we were getting "COM Surrogate" errors, which relate to DEP errors with the dllhost.exe system program. Adding it to the exception list didn't solve our problem.

Solution

Thankfully, Microsoft has written an article on how to turn off DEP for an entire server. For this case, you need to add the following option:

/noexecute=AlwaysOff

to your boot.ini file.

See A detailed description of the Data Execution Prevention (DEP) feature in Windows XP Service Pack 2, Windows XP Tablet PC Edition 2005, and Windows Server 2003 (Microsoft Support) for further information.

Versions

Microsoft Windows Server 2003
Microsoft Commerce Server 2002
Also applicable to Microsoft Windows XP

Metadata

Categories: IT Management, Security, Windows Server, Commerce Server
Additional keywords: how to turn off DEP, disable DEP
Technorati Tags: IT Management, Windows, Windows 2003, problem, DEP, Data Execution Prevention, Commerce Server

Commerce Server 2002: BizDesk Campaign Manager Fails with "Call to Server.CreateObject Failed While Checking Permissions" Error Message

Stephen Horsfield — Tue, 08 Jan 2008 12:44:33 GMT

Read the article...

Excerpt

The above error was occurring on both staging and live environments for a Microsoft Commerce Server 2002 system. It took us a while to track down the cause, but eventually I fixed it.

References

Microsoft KB Article 811306

Versions

Microsoft Windows Server 2003
Microsoft Commerce Server 2002

Metadata

Technorati Tags: IT Management, Windows, Windows 2003, problem, Commerce Server

Commerce Server 2002: Reporting — Query Best Practice

Stephen Horsfield — Mon, 07 Jan 2008 19:41:55 GMT

Overview

How can you make your Commerce Server reports easy to maintain, and how can you make it work with long SQL queries? Did you even know that long SQL queries won't always work?!

The problem

The query is stored in the Report table in SQL Server as an nvarchar(2000) field. This means you've only got 2000 characters to work with. In fact, the limit is smaller than this because of processing that Commerce Server is doing itself. I noticed problems around 900 characters, which seems a bit small!

The solution

The best solution I found was to reference a SQL view that was created for the purpose. Using this, the SQL query just needed to select the particular fields, apply particular filters (such as date filtering) and sorting. This meant that changes to the underlying report execution could be managed by adjusting the view rather than the SQL in the Report table. The view can also be used by many similar reports, which in our case was for about 10 regional sites.

One main caveat was the use of Commerce Server date report parameters. The filtering on this only worked when it was in the Report Query field directly.

Versions

Microsoft Commerce Server 2002
Microsoft SQL Server 2000
Microsoft Windows Server 2003

Metadata

Technorati Tags: software development, Windows, Windows 2003, Commerce Server SQL, SQL Server, reporting

Windows: The Windows Time Service

Stephen Horsfield — Sun, 06 Jan 2008 10:53:07 GMT

Overview

The time service is a critical part of any Windows Active Directory infrastructure. Why? Because it is part of how Active Directory replicates correctly, because it supports the implementation of Kerberos and because all your networked computers will be synchronised using it, even if you don't configure it.

Quite often, a seemingly unrelated error message will be caused by time service configuration errors. I've written small guidance notes quite often to help administrators sort out these problems, but I wanted to collect my knowledge into a single blog post so that it is available for everyone.

This knowledge has been accrued over several years, referencing many blogs, Microsoft knowledge base articles and books in production environments. I'll reference what I can, but the rest is straight out of my head...

Normative operation

When working correctly, the time service ensures that all servers and workstations in the Active Directory forest have the correct time configured. See How Windows Time Service Works (Microsoft TechNet) for the authoritative reference on this.

By default, all forest member computers with one exception (more in a moment) will synchronise their clocks to this one authority. The authority is the domain controller in the forest root domain that is configured to be reliable. Normally, this will mean the domain controller that has the PDC-emulator FSMO role.

Communication with the Windows Time Service between computers is authenticated by Kerberos. Kerberos will allow small deviations in clocks but anything more than about 5 minutes is likely to cause an authentication failure, thereby preventing the clock correction that would enable Kerberos authentication! If your clocks are already out of sync, then you will need to adjust them manually. See Basic Concepts for the Kerberos Protocol (Microsoft TechNet) for a conceptual look at Kerberos.

Although the time service can use hardware devices to ensure accuracy, the most common scenario is the use of a public NTP time service.

Symptoms of failure

The following list are common symptoms that may indicate an underlying time synchronisation error:

Outlook 2007 can't connect to Exchange Server. It keeps prompting for credentials. By default, Outlook 2007 uses the Negotiate method for authentication. This results in it using Kerberos rather than NTLM and the client can't connect if the clocks are skewed by five minutes or more. See You are repeatedly prompted to enter your credentials when you try to connect to an Exchange 2003 mailbox by using Outlook 2007 (Microsoft Support)
You can't access some or all network resources
You can't logon to a domain computer that you haven't recently logged on to
Domain trusts aren't working, or replication is failing:
- There are currently no logon servers available to service the logon request
- The trust cannot be validated
- Windows cannot find a domain controller for the ... domain
Group Policy not being applied correctly
Offline Files not synchronising correctly, possibly deleting files

Virtual servers and Windows guests

In general, you should not synchronise the host time and the guest time. If you do, you undermine the operation of the Windows Time Service. This can affect any virtual server solution including Microsoft Windows Hyper-X, Microsoft Virtual Server, Microsoft Virtual PC, VMWare Server, VMWare ESX Server and Xen.

You may be affected by this if you have a hosted solution. Check that your service provider is not attempting to synchronise the clock on the virtual machine.

Configuration

To configure the time service, you first need to find appropriate servers for your root domain PDC to connect to. You can use multiple Internet providers, but ideally they should be in the same time zone as the server. See the following for public NTP server lists:

Next, you need to decide on which flags to use. These flags control how the server will connect to the public NTP server, and are required for correct function. Microsoft documents the use of the 0x1 flag for use with NTP servers specified by a DNS name (such as time.windows.com). However, with these public time servers you typically also need the 0x8 flag which puts the NTP connection into a client mode. See here for reference: Windows Time Service (Microsoft TechNet).

There are several ways in which you can make the changes on the PDC:

Edit the registry directly
Use the NET TIME /SETSNTP command
Use the W32TM command

The service must be restarted after the changes have been made. A typical command looks like the following:

w32tm /config "/manualpeerlist:ntp.domain1.com,0x8 ntp.domain2.com,0x8 ntp.domain3.com,0x8" /syncfromflags:manual

See here W32tm (Microsoft TechNet) for more on the W32TM command.

Note that I haven't used the 0x1 flag in this configuration. I've used this style for many years and it has been successful. If it works, leave it alone :)

Also notice that I've surrounded the manualpeerlist option in quotes and separated the servers with a single space character. This is the correct syntax.

Other considerations

The NTP protocol uses UDP port 123 for both source and destination, so you'd better make sure that the firewall is going to allow the connection. Also, because it is a session-less connection (UDP not TCP), timeouts can be a factor. If you see lots of blocked UDP 123 packets at your firewall, coming from the configured NTP servers, then they are probably late replies. You might need to consider increasing the timeout or creating a static route. This can be quite common.

You might also get the occasional event log entry suggesting that connectivity to one or all NTP servers is down. This may be because the server is down, or because the reply is too late. Infrequent messages like this are nothing to worry about. The time service will log a further event indicating that the connection has been reestablished as soon as it has.

Troubleshooting

Search Microsoft Support (http://support.microsoft.com) for "w32time events" to find many more potential solutions. Also, remember to install service packs. Several issues were resolved with Windows 2000 Service Packs 2 and 3.

Versions

Windows Server 2008
Windows Server 2003
Windows Server 2000

Metadata

Technorati Tags: Windows, Windows 2003, IT Management, Windows Time Service, kerberos, Active Directory, best practice, troubleshooting, NTP