Hello

We are having some issues with site stability.

One template deals with a file archive which consists of a lot of images, so there's a lot of re-scaling going on. A feature that will rotate an image (using the Webnodes library) is also in place. The site will consistently hang if an image is rotated (by the request of a user).

In the course of our investigation we have been made aware of that the classes in System.Drawing can cause site stability issues. This is specifically mentioned under https://msdn.microsoft.com/en-us/library/system.drawing.aspx:

Classes within the System.Drawing namespace are not supported for use within a Windows or ASP.NET service. Attempting to use these classes from within one of these application types may produce unexpected problems, such as diminished service performance and run-time exceptions. For a supported alternative, see Windows Imaging Components.

Hence, I was wondering if Webnodes internally utilizes System.Drawing for re-scaling or rotation, or utilizes any libraries that themselves make use of this namespace.

Regards,

-Emil

There are no crashes, but while the rotation occurs the site remains unresponsive for other users as well. It's consistent. I am unsure however, if image file uploads and the following re-scaling operation also plays a part. Of course it's not a problem once the different image versions have been cached, but there are a lot of uploads and user actions going on.

Here is an also interesting article :)

http://weblogs.asp.net/bleroy/resizing-images-from-the-server-using-wpf-wic-instead-of-gdi

And apparently, if images are not properly Dispose()ed of it might cause serious harm (although I doubt that is the problem in our case):

http://www.asprangers.com/post/2012/03/23/Why-you-should-not-use-SystemDrawing-from-ASPNET-applications.aspx

EDIT: Build is 1597

As a follow-up:

The system hangs only when performing rotations, not when re-scaling.