Commented Issue: Tracing should trace warning not error for HttpResponseException [949]

The default trace writers do not currently special-case HttpResponseException, and therefore trace at TraceLevel.Error. This is confusing, because it means simple user error in the URI will generate an error trace. This makes it hard to use the tracing layer to report errors. The System.Diagnostic, ETW, and Memory trace writers all try to correct for this to convert it back into a warning.

Recommend the default tracing logic should trace at TraceLevel.Warn whenever the exception is HttpResponseException.
Comments: fixed on https://aspnetwebstack.codeplex.com/SourceControl/changeset/6962d5f3baed9d2b13ddff7f172895e843948100