IIS Informant

I'm using IIS 5.0, and I've been having problems getting my site to run. I'm using server-side Include statements in my documents to control document appearance and content, so I've mapped my .htm files to ssinc.dll, which processes server-side Include statements in .htm files. I've set everything up correctly, and I've checked the permissions extensively. Nevertheless, I continually receive a dialog box requesting a name and password as if a security problem existed. How can I fix this problem?

You've encountered a known bug in IIS 5.0, which the Microsoft article "Access Denied for the Default Document File Mapped to ssinc.dll" (http://support.microsoft.com/support/ kb/articles/q246/8/06.asp) describes. The problem occurs when the default document for your system (e.g., default.htm, default.stm, index .html—whatever default document you've specified) contains an #include statement and is processed by ssinc .dll. In this scenario, IIS 5.0 always sends error 401 Access Denied, which results in the security challenge. Contact Microsoft Product Support Services (PSS) for a patch. (This bug is fixed in Windows 2000 Service Pack 1—SP1.)

I recently upgraded to IIS 5.0. Since the upgrade, I've been receiving error 500-12 Application restarting. The error is related to Active Server Pages (ASP) and appears to be random. I haven't loaded anything unusual, and I didn't have this problem in IIS 4.0. How can I prevent this error?

This kind of problem can be maddening. My best guess is that you're suffering from a problem with IIS 5.0 that occurs when IIS recompiles the global.asa file. Making changes to global.asa requires that IIS recompile the file. When IIS detects such a change, it executes an orderly shutdown of running applications, recompiles global.asa, and relaunches the applications. If users attempt to connect to the server during the recompiling and application restart, they receive error 500-12 Application restarting.

Now, the question remains—Why is IIS performing this restart? As it turns out, antivirus software running on an IIS 5.0 server can cause IIS to think it needs to recompile global.asa. This scenario results in the symptoms you describe—apparently random restarts associated with ASP.

For information about this problem, see the Microsoft article "Err Msg: HTTP Error 500-12 Application Restarting" (http://support.microsoft.com/ support/kb/articles/q248/0/13.asp). No fix was available at the time of publication; the workaround is to refresh the browser.

I'm trying to connect 1000 clients to one IIS 4.0 system. These clients are issuing URLs that result in the execution of an Internet Server API (ISAPI) extension. Microsoft Performance Monitor shows that the Web Server:Current ISAPI Extension Requests counter gets to 256 before IIS starts returning WinInet error 12029 Cannot connect. I've set these configuration values:

Web Site (default web site)
Connections: unlimited
Performance
Hits per day: Greater than 100,000
HTTP Keep-Alives Enabled: yes

Is there a configuration value or Registry setting I can use to increase the number of outstanding ISAPI requests that IIS 4.0 supports?

IIS can handle this load without much trouble, so the focus lies not on tuning IIS but on your ISAPI extension. You must implement specific programming techniques to achieve scalability, or you're going to have the kinds of problems you're seeing.

A good resource for information about ISAPI behavior is Leonid Braginski and Matthew Powell, Running Microsoft Internet Information Server (Microsoft Press, 1998). The extension needs to create worker threads, then release its original thread back to the pool. Of course, you must turn ISAPI caching on. I'd take page 551 of this book to the programmers and see whether they're using DllMain or GetExtensionVersion to create the private pools. In addition, managing access to global resources is crucial. Also, you'll get better performance from IIS 5.0 than from IIS 4.0. (Thanks to reader Craig Weeks for this question.)

   Previous  [1]  2  3  Next