We've been experiencing sporadic performance issues with one of ours ASP.NET sites.

I set up failed request tracing to log any request that takes more than 15 seconds.

What I'm seeing is, these events are taking the most time:

• AspNetGetAppDomainLeave
• AspNetStartHandler
• AspNetGetAppDomainLeave
• AspNetStartHandler
• AspNetMapHandlerLeave
• AspNetPagePreRenderLeave
• AspNetSessionDataEnd
• AspNetPagePreInitLeave

With AspNetGetAppDomainLeave being the predominant one, usually taking between 11 seconds to 15 seconds.

Can anyone help me to interpret what these events mean?

Thanks