We are using Telerik.Wb.UI rev 2010.2.713.20, VB.NET, and IIS 7.
Following is a "telerik:RadCaptcha" element in one of our web pages:
<telerik:RadCaptcha ID="RadCaptcha1" ImageStorageLocation="Session"
runat="server" ErrorMessage="Page not valid. The code you entered is not valid."
ValidationGroup="vgAudio"
ValidatedTextBoxID="rcTextBox1"
Display="None">
<CaptchaImage
EnableCaptchaAudio="true"
RenderImageOnly="true"
ImageCssClass="rcCaptchaImage"
BackgroundColor="#609f0a"
TextColor="White"
BackgroundNoise="None" />
</telerik:RadCaptcha>
We have been noticing that each time the page is refreshed/reloaded, a Captcha Image is added to the Session using a new GUID as the key. The problem we are running into is that the session object gets very large as crawlers load this page many many time over the life of a single session. The Session gets so large that we have to run a scheduled task to forcefully abandon the session periodically.
We have used the "CaptchaMaxTimeout" property to set the timeout to just a couple of minutes and observe that Captcha images do not seem to be removed from the cache (Session) when the timeout period expires.
How can I prevent/limit caching of Captcha images to avoid this situation?
Following is a "telerik:RadCaptcha" element in one of our web pages:
<telerik:RadCaptcha ID="RadCaptcha1" ImageStorageLocation="Session"
runat="server" ErrorMessage="Page not valid. The code you entered is not valid."
ValidationGroup="vgAudio"
ValidatedTextBoxID="rcTextBox1"
Display="None">
<CaptchaImage
EnableCaptchaAudio="true"
RenderImageOnly="true"
ImageCssClass="rcCaptchaImage"
BackgroundColor="#609f0a"
TextColor="White"
BackgroundNoise="None" />
</telerik:RadCaptcha>
We have been noticing that each time the page is refreshed/reloaded, a Captcha Image is added to the Session using a new GUID as the key. The problem we are running into is that the session object gets very large as crawlers load this page many many time over the life of a single session. The Session gets so large that we have to run a scheduled task to forcefully abandon the session periodically.
We have used the "CaptchaMaxTimeout" property to set the timeout to just a couple of minutes and observe that Captcha images do not seem to be removed from the cache (Session) when the timeout period expires.
How can I prevent/limit caching of Captcha images to avoid this situation?