Use Azure CDN Custom Origin for items in Sitecore media library

Using a CDN can significantly improve loading times of your site as static resources like images can be retrieved from it. A CDN has many edge servers and will automatically serve the resource from the closest location to the user. Additionally they will decrease the load on the webserver as it does not need to serve the resource to individual users.

Last year Azure announced custom origin support in their CDN. Before that you could only use the CDN from a limited set of Azure services in your Azure subscription like the Cloud Service that hosted your Sitecore environment. I have seen some complicated solutions to have the CDN use Sitecore. This was especially complicated if the cloud service hosted multiple Sitecore instances. Using the CDN is much easier with this new policy. This post will describe the steps involved in setting this up.

The first step is to set up the Azure CDN with custom origin, use the URL of your Sitecore site as the origin URL. This can be done either on the new or classic Azure Portal, see screenshots below:

Classic portal:

When the CDN is created it will generate a URL for it, something like It is also possible to map a custom domain to this endpoint see here

Now the CDN is ready to use and you can retrieve any media library item, for example if your image has a URL of then you can load it now from

The CDN is now ready to use however the CDN edge servers will not cache the image but instead return it from the origin which is the Sitecore server. This is because by default Sitecore sets cache-control to private which causes the CDN not to cache it. This has to be changed to public in the Sitecore settings:

<configuration xmlns:patch="">
      <setting name="MediaResponse.Cacheability">
        <patch:attribute name="value">public</patch:attribute>

Now static resources will be cached by Azure’s CDN edge servers so site will load faster for your users.


Sitecore WFFM 8.1 incorrectly detects forged request

Sitecore Web Forms For Marketers 8.1 rev.151217 (Update-1) has recently been released, see release notes here As mentioned in the release notes this includes a new feature to prevent forging request.

For some reason I’m seeing valid request (the initial form was served by the Sitecore server and is submitted back to the same server) incorrectly being detected as forged request which causes the form the error. I’m currently working with Sitecore to try to understand why this is happening and understand what the root cause is. I will let you know if i figure out this issue.

Please let me know if anyone else is running into the same issue hopefully it can help troubleshoot this. Also Sitecore can provide a custom DLL which avoids the page crashing in this scenario.

GlassMapper GetRenderingParameters returning null after upgrade

If you have recently upgraded GlassMapper you might run into an issue where GetRenderingParameters returns null. I believe this started occuring in version or I was only experiencing this in WebForms. The issue occurs when you call GetRenderingParameters as described in this article (section “ASP .NET Webforms”).

The good news is that this issue has already been reported so hopefully it will be fixed in the next release. If you really need to upgrade to a version with this issue then you can easily fix this by downloading the code from github here and compiling Glass.Mapper.Sc DLL yourself.

The only code change that is required is to change

var sublayout = _control as Sublayout;

to remove underscore in control to reference the method parameter

var sublayout = control as Sublayout;

On line 40 of GetRenderingParametersInternal in Glass.Mapper.Sc.Web.Ui.GetRenderingParametersInternal see file in Github here