Yes, that is exactly the issue. Just my humble opinion, but Log4Net would only incur the try/catch perf penalty during user logging inside Application_Start, which is a very tiny percentage of the lifetime of an ASP.Net application.
The issue for log4net is that people staticly define their layout patterns that they want in the web.config. It's not obvious to me how they could "instruct" log4net to ignore the aspnet layout patterns while inside Application_Start. I don't know any other way to test the viability of calling through get_Request() before the fact. Cheers, George On Fri, Mar 30, 2012 at 2:30 PM, Alessandro Ghizzardi <box.ml...@phaseit.com > wrote: > Hi George, > > It seems more like an architecture problem in logging that point, instead > of a bug. It used to work in older version, but probably you're using IIS7 > in integrated mode and request is not available anymore. > If you really need to log in application start probably this workaround > can help you > > > http://mvolo.com/blogs/serverside/archive/2007/11/10/Integrated-mode-Request-is-not-available-in-this-context-in-Application_5F00_Start.aspx > > Best > Alessandro Ghizzardi > Moving... > > Il giorno 30/mar/2012, alle ore 22:59, George Chung <geo...@glympse.com> > ha scritto: > > The subtlety is that in Application_Startup(), httpContext is indeed not > null and httpContext.Request is really httpContext.get_Request(). > > And it is the act of calling get_Request() that throws the HttpException. > > On Fri, Mar 30, 2012 at 1:51 PM, Johnson, Thomas < > thomas.john...@lpsvcs.com> wrote: > >> Sorry: if (httpContext != null && httpContext.Request != null)**** >> >> ** ** >> >> Since you’re in c# the second statement won’t be evaluated if the first >> is false and you will avoid NRE**** >> >> ** ** >> >> *From:* Johnson, Thomas >> *Sent:* Friday, March 30, 2012 2:50 PM >> *To:* log4net-dev@logging.apache.org >> *Subject:* RE: Proposed bug fix for >> AspNetRequestPatternConverter.Convert()**** >> >> ** ** >> >> Typically you want to avoid code like this // maybe just do: if >> (httpContext != null) { //the entirety of your method } else >> writer.Write(SystemInfo.NotAvailableText);**** >> >> ** ** >> >> try**** >> >> {**** >> >> request = httpContext.Request;**** >> >> if (request == null)**** >> >> requestExists = false;**** >> >> }**** >> >> catch (System.Web.HttpException)**** >> >> {**** >> >> requestExists = false;**** >> >> }**** >> >> ** ** >> >> ** ** >> >> *From:* George Chung [mailto:geo...@glympse.com] >> *Sent:* Friday, March 30, 2012 1:29 PM >> *To:* log4net-dev@logging.apache.org >> *Subject:* Proposed bug fix for AspNetRequestPatternConverter.Convert()** >> ** >> >> ** ** >> >> Hello,**** >> >> I'm new to this mailing list. Sorry if this is not the appropriate way to >> report a bug fix. Dereferencing HttpContext.Request will throw an exception >> if you call it in an Asp.net application's Application_Start().**** >> >> ** ** >> >> Thus, if you have log4net logging *and* you use a pattern layout format >> like %aspnet-request{REMOTE_ADDR} *and* you call Log4net inside >> Application_Start(), Log4net will throw an exception trying to log the >> message. The stack will look like this:**** >> >> ** ** >> >> log4net:ERROR [RollingFileAppender] ErrorCode: GenericFailure. Failed in >> DoAppend**** >> >> System.Web.HttpException (0x80004005): Request is not available in this >> context**** >> >> at System.Web.HttpContext.get_Request()**** >> >> at >> log4net.Layout.Pattern.AspNetRequestPatternConverter.Convert(TextWriter >> writer, LoggingEvent loggingEvent, HttpContext httpContext)**** >> >> at >> log4net.Layout.Pattern.AspNetPatternLayoutConverter.Convert(TextWriter >> writer, LoggingEvent loggingEvent)**** >> >> at log4net.Layout.Pattern.PatternLayoutConverter.Convert(TextWriter >> writer, Object state)**** >> >> at log4net.Util.PatternConverter.Format(TextWriter writer, Object >> state)**** >> >> at log4net.Layout.PatternLayout.Format(TextWriter writer, LoggingEvent >> loggingEvent)**** >> >> at log4net.Layout.Layout2RawLayoutAdapter.Format(LoggingEvent >> loggingEvent)**** >> >> ** ** >> >> ** ** >> >> Here is my proposed fix:**** >> >> ** ** >> >> ** ** >> >> internal sealed class AspNetRequestPatternConverter : >> AspNetPatternLayoutConverter**** >> >> {**** >> >> /// <summary>**** >> >> /// Write the ASP.Net Cache item to the output**** >> >> /// </summary>**** >> >> /// <param name="writer"><see cref="TextWriter" /> that will receive >> the formatted result.</param>**** >> >> /// <param name="loggingEvent">The <see cref="LoggingEvent" /> on >> which the pattern converter should be executed.</param>**** >> >> /// <param name="httpContext">The <see cref="HttpContext" /> under >> which the ASP.Net request is running.</param>**** >> >> /// <remarks>**** >> >> /// <para>**** >> >> /// Writes out the value of a named property. The property name**** >> >> /// should be set in the <see >> cref="log4net.Util.PatternConverter.Option"/>**** >> >> /// property.**** >> >> /// </para>**** >> >> /// </remarks>**** >> >> protected override void Convert(TextWriter writer, LoggingEvent >> loggingEvent, HttpContext httpContext)**** >> >> {**** >> >> bool requestExists = true;**** >> >> **** >> >> HttpRequest request = null;**** >> >> try**** >> >> {**** >> >> request = httpContext.Request;**** >> >> if (request == null)**** >> >> requestExists = false;**** >> >> }**** >> >> catch (System.Web.HttpException)**** >> >> {**** >> >> requestExists = false;**** >> >> }**** >> >> **** >> >> if (requestExists)**** >> >> {**** >> >> if (Option != null)**** >> >> {**** >> >> WriteObject(writer, loggingEvent.Repository, >> request.Params[Option]);**** >> >> }**** >> >> else**** >> >> {**** >> >> WriteObject(writer, loggingEvent.Repository, >> request.Params);**** >> >> }**** >> >> }**** >> >> else**** >> >> {**** >> >> writer.Write(SystemInfo.NotAvailableText);**** >> >> }**** >> >> }**** >> >> }**** >> >> The information contained in this message is proprietary and/or >> confidential. 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