KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q253146: Tuning the Performance and Scalability of ASP Web Applications

Article: Q253146
Product(s): Internet Information Server
Version(s): winnt:5.0
Operating System(s): 
Keyword(s): kbIIS kbiis500
Last Modified: 23-OCT-2000

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Internet Information Services version 5.0 
-------------------------------------------------------------------------------

SUMMARY
=======

This article provides some generic information about possible
performance-enhancement settings that may be helpful to tune Internet
Information Server (IIS) 5.0. The default settings for Internet Information
Services 5.0 are adequate for most uses. When you host sites serving a large
number of users, tuning the parameters listed in the "More Information" section
of this article may help to increase performance. All changes should be verified
on a test computer before you make changes to a production computer.

MORE INFORMATION
================

AspProcessorThreadMax:

The AspProcessorThreadMax metabase property specifies the maximum number of
worker threads per processor that IIS creates. The setting can dramatically
influence the scalability of your Web applications and the performance of your
server in general. Because it defines the maximum number of ASP requests that
can run simultaneously, this setting should remain at the default unless your
ASP applications are making long-running calls to external components. By
default, AspProcessorThreadMax is set to 25.

AspRequestQueueMax:

The AspRequestQueueMax metabase property specifies the maximum number of
concurrent ASP requests that are permitted into the queue. Any client browsers
attempting to request ASP files when the queue is full are given an HTTP 500
"Server too busy" error message. By default, AspRequestQueueMax is set to 3000.

AspQueueConnectionTestTime:

IIS places all ASP requests into a queue. If the request has been queued for
longer than the number of seconds specified by the AspQueueConnectionTestTime
metabase property, ASP checks to determine whether the client is still connected
before it executes the request. If the client is no longer connected, the
request is not processed and is deleted from the queue. You can use the
AspQueueConnectionTestTime metabase property to make sure that IIS does not
waste time processing a request that has been abandoned by the user. By default,
AspQueueConnectionTestTime is set to 3.

AspScriptEngineCacheMax:

The AspScriptEngineCacheMax property specifies the maximum number of scripting
engines that ASP pages will keep cached in memory. By default,
AspScriptEngineCacheMax is set to 125.

AspSessionTimeOut:

The AspSessionTimeOut property specifies the default amount of time (in minutes)
that a session object is maintained after the last request associated with the
object is made. AspSessionTimeOut can be used to tune your ASP applications.
Because session objects consume some memory resources, limiting the lifetime of
an individual session with this property makes your applications more scalable.
By default, AspSessionTimeOut is set to 20.

WARNING: Modifying the metabase incorrectly can cause serious problems that may
require you to reinstall IIS 5.0. Microsoft cannot guarantee that problems
resulting from incorrectly modifying the metabase can be resolved. Modify the
metabase at your own risk.

Run the Adsutil.vbs utility from the <%SYSTEMDRIVE%>\inetpub\adminScripts
directory. For example, to reconfigure the AspRequestQueueMax metabase property,
type the following command:

  adsutil.vbs set w3svc/AspRequestQueueMax <NewValue>

Where <NewValue> is the number of requests that ASP should use per
processor.

Note: For all entries, these settings change the value at the Master WWW
Properties level, where they are inherited by all new Web applications and all
existing applications that have not explicitly set a different value.

REFERENCES
==========

  Q238583 How to Tune the ASPProcessorThreadMax

  Q233477 PRB: Session.Timeout Has a Max of 24 Hours

Additional query words:

======================================================================
Keywords          : kbIIS kbiis500 
Technology        : kbiisSearch kbiis500
Version           : winnt:5.0
Issue type        : kbinfo

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.