Microsoft KB Archive/147191

= IIS FTP Server Users May Experience Delayed Responses =

Article ID: 147191

Article Last Modified on 6/23/2005

-

APPLIES TO


 * Microsoft Internet Information Server 1.0

-



This article was previously published under Q147191



We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 6.0 running on Microsoft Windows Server 2003. IIS 6.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:

http://www.microsoft.com/technet/security/prodtech/IIS.mspx





SYMPTOMS
Microsoft Internet Information Server FTP clients experience delayed responses to commands when a large number of users are logged on through FTP. This symptom occurs sporadically. File transfer speeds are not affected.



CAUSE
The default number of threads per processor (MaxPoolThreads) installed on your system is 10. This may be not be sufficient for a heavily used FTP server because some of the FTP commands use synchronous I/O, causing threads to block while they complete.



RESOLUTION
To allow more processor threads for IIS FTP clients, do the following in the registry.

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.


 * 1) Start Registry Editor (REGEDT32.EXE) and locate the following Registry subkey in the HKEY_LOCAL_MACHINE subtree:

\SYSTEM\CurrentControlSet\Services\InetInfo\Parameters
 * 1) From the Edit menu, select Add Value.
 * 2) Enter the following:

Value Name: MaxPoolThreads

Data Type: REG_DWORD

String: 

NOTE: A twin processor with 500 to 1000 concurrent users may require 50 or more threads per processor to provide quick response for all FTP client users.
 * 1) Choose OK and quit the Registry Editor.
 * 2) Shut down and restart Windows NT.



STATUS
Microsoft has confirmed this to be a problem in Internet Information Server version 1.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: prodiis cwd list

Keywords: kbnetwork KB147191

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.