Prolific Notion » Windows Server 2008

ELMAH – An attempt was made to load a program with an incorrect format.

Simon Dingley — Thu, 18 Nov 2010 11:36:45 +0000

Following the recent series of posts on issues I have had migrating client sites from IIS6 to IIS7, one common problem I had was on sites that use the ELMAH exception handler. The full exception message is “Could not load file or assembly ‘System.Data.SQLite’ or one of its dependencies. An attempt was made to load a program with an incorrect format. “.

Another easy fix for this one but rather than it being a config issue relating to the IIS version I believe this is more related to the move from a 32-Bit server to a 64-Bit Windows Server. To correct the issue you need to modify the advanced settings for your app pool to “Enable 32-Bit Applications”.

Related posts brought to you by Yet Another Related Posts Plugin.

Use AppCmd to Migrate web.config from IIS6 to IIS7

Simon Dingley — Wed, 17 Nov 2010 19:21:44 +0000

Further to my earlier post I encountered another issue migrating sites for a client from IIS6 to IIS7. If your site uses any httpHandlers or httpModules you will need to perform these steps to migrate your web.config to include the missing configuration sections required by IIS7.

First of all I would suggest listing out all sites using AppCmd and the following command:

%systemroot%\system32\inetsrv\APPCMD list sites

Your output should be similar with the following:

SITE "Default Web Site" (id:1,bindings:HTTP/*:80:,state:Started)

SITE "Site1" (id:2,bindings:http/*:81:,state:Started)

SITE "Site2" (id:3,bindings:http/*:82:,state:Stopped)

Make a note of the object specific identifier in quotes as you will need this to specify the website/app whose web.config you wish to migrate.

Next you will need to run another command to perform the migration as follows:

%systemroot%\system32\inetsrv\APPCMD.EXE migrate config "object-specific-identifier/"

There is a very important point worth noting here as it caught me out for quite a while, be sure to include a trailing slash after your object specific identifier or the command will fail.

All being well your should get a message similar to this confirming the web.config has been migrated.

Successfully migrated section "system.web/httpModules".
Successfully migrated section "system.web/httpHandlers".

That’s it, for me the app was back up and running again after these steps.

Related posts brought to you by Yet Another Related Posts Plugin.

Page.User is null on IIS7 in Integrated Mode with UrlRewriting.Net

Simon Dingley — Wed, 17 Nov 2010 15:47:25 +0000

I am in the process of migrating a large number of sites from a Windows 2003 Server to a Windows 2008 R2 Server for a client. When testing the migrated sites I kept getting the all too familiar ‘Object reference not set to an instance of an object’ exceptions. As the site was in debug mode at this stage I got the full stack trace and was able to pinpoint the problem to the Page.User object being null. Strange as it was working fine on IIS6 so there must be something different in IIS7 that is causing the exception.

After some research I discovered an easy fix to the problem which requires you to add an attribute to the modules node in the system.webServer configuration section of your web.config file as follows:

Magically the error disappears after adding this. See the ‘Tip/Trick: Url Rewriting with ASP.NET‘ post on Scott Guthries blog for more details on this.

Related posts brought to you by Yet Another Related Posts Plugin.

Problems with Windows Server Hosted in the Cloud Maintaining Correct Time

Simon Dingley — Fri, 22 Oct 2010 22:23:00 +0000

I currently maintain two windows based servers in the cloud with Elastic Hosts, one of my own and one for a client. On both I have scheduled tasks running and noticed that the time was slipping on the execution of these tasks over time. It became apparent that the server was unable to maintain the correct time and I was unable to figure out why so a quick email to the support team and the issue was solved within the hour!

It appears that the issue is the emulation of the hardware clock by the virtualization system. On Linux and other Unix based operating systems, the convention is that the hardware clock is permanently set to UTC (i.e. GMT without DST), and the operating system adjusts this for display. On DOS and Windows, the convention is that the hardware clock stores local time, and that the operating system adjusts this when DST starts and ends. The host cannot support both of these behaviours, since their virtualization layer does not know what operating system it will boot when it sets up the virtual hardware to start a server. As they have chosen the UTC behaviour something needs to change in my operating system to compensate for this.

The solution was to locate the following entry in the registry on the server:

HKLM\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\RealTimeIsUniversal

Setting the value of this registry entry to 1 solved the problem for me. Further information on the topic can be found at http://www.cl.cam.ac.uk/~mgk25/mswish/ut-rtc.html

Related posts brought to you by Yet Another Related Posts Plugin.

Discover which ASP.Net Worker Process Belongs to each AppPool

Simon Dingley — Fri, 23 Jul 2010 07:43:25 +0000

Ever needed to know which ASP.Net worker process (w3wp.exe) belongs to an App Pool? Well I did recently when I needed to attach to it for debugging and there was no obvious way to find out which process related to each app pool. A little bit of research led me to discover AppCmd.exe. I wrote a small batch file which will list them all for you and include the process id. Simply copy the following into a blank text file and save with a .bat extension and you can run it whenever you need to, alternatively just run the command through a standard command prompt.

cd %systemroot%\system32\inetsrv
appcmd list wps
pause

You should end up with a line like the following for each worker process on your machine:

WP "5528" (applicationPool:DefaultAppPool)

No related posts.

Related posts brought to you by Yet Another Related Posts Plugin.

Setup SMTP Logging on Windows Server 2008 by enabling the ODBC Logging module

Simon Dingley — Fri, 02 Jul 2010 21:15:13 +0000

I recently had a client who had some issues delivering mail from their site so I went to look at the SMTP logs only to find that there were none there (I am embarrassed to say). I notice that I had configured the logs to be written to a custom directory on a separate drive from the operating system and thought that may have been the issue however it turns out that there are some steps that needs to be taken in order for SMTP logging to work on Windows Server 2008. It’s odd enough that you need to use the legacy IIS 6 management console to administer your SMTP Server but there is also no obvious steps when setting up your server that indicate the requirements for SMTP logging.

To get logging working you need to install the ODBC Logging module by following these steps:

On the taskbar, click Start, point to Administrative Tools, and then click Server Manager.
In the Server Manager hierarchy pane, expand Roles, and then click Web Server (IIS).
In the Web Server (IIS) pane, scroll to the Role Services section, and then click Add Role Services.
On the Select Role Services page of the Add Role Services Wizard, select ODBC Logging, and then click Next.
On the Confirm Installation Selections page, click Install.
On the Results page, click Close.

Problems with Windows Server Hosted in the Cloud Maintaining Correct Time

Related posts brought to you by Yet Another Related Posts Plugin.