FIX: Kernel-pool memory may become exhausted when many clients connect to Message Queuing

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Article ID: 870985 - View products that this article applies to.

Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows Registry
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SYMPTOMS

When many clients connect to Microsoft Message Queuing, also known as MSMQ, Message Queuing may exhaust its kernel-pool memory. This problem may become worse when Message Queuing executes Active Directory queries while processing incoming messages. Validating client certificates is an example of an incoming message.

CAUSE

This problem may occur when many Message Queuing clients connect to Message Queuing at the same time. This causes an accumulation of Transmission Control Protocol (TCP) buffers in the kernel-pool memory. This TCP buffer-pool memory accumulation is the result of many outstanding messages that are not promptly processed by Message Queuing.

RESOLUTION

Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

Hotfix information

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:
http://support.microsoft.com/contactus/?ws=support
Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites

You must have Service Pack 4 or later.

Restart requirement

You must restart your computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfix.

File information

The English version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
  
   Date         Time   Version            Size    File name
   --------------------------------------------------------------
   13-Jul-2004  17:50  5.0.0.792         291,088  Mq1repl.dll      
   22-Dec-2003  22:26  5.0.0.791          14,096  Mq1sync.exe      
   11-May-2004  15:34  5.0.0.794          76,944  Mqac.sys
   13-Jul-2004  17:50  5.0.0.791         217,360  Mqads.dll        
   20-Sep-2003  19:23  5.0.0.761          25,360  Mqbkup.exe       
   13-Jul-2004  17:50  5.0.0.785          76,560  Mqdscli.dll      
   13-Jul-2004  17:50  5.0.0.773          42,256  Mqdssrv.dll      
   22-Dec-2003  22:26  5.0.0.791          98,064  Mqmig.exe        
   13-Jul-2004  17:50  5.0.0.791         266,512  Mqmigrat.dll     
   13-Jul-2004  17:50  5.0.0.793         222,480  Mqoa.dll         
   13-Jul-2004  17:50  5.0.0.784          10,000  Mqperf.dll       
   13-Jul-2004  17:50  5.0.0.797         437,520  Mqqm.dll         
   13-Jul-2004  17:50  5.0.0.778         102,672  Mqrt.dll         
   13-Jul-2004  17:50  5.0.0.776          70,928  Mqsec.dll        
   13-Jul-2004  17:50  5.0.0.783         400,656  Mqsnap.dll       
   13-Jul-2004  17:50  5.0.0.762          23,824  Mqupgrd.dll      
   13-Jul-2004  17:50  5.0.0.793         110,864  Mqutil.dll       
   13-Jul-2004  17:50  5.0.0.748          64,784  Msmq.cpl

The hotfix that is discussed in this article limits the number of clients that can connect to Message Queuing. This hotfix adds two registry entries that may cause the client to have its connection reset when that client tries to connect to Message Queuing. This behavior occurs if the threshold is reached. The client must wait until another connection is available. The new registry entries follow:
  • MaxInSessions
  • WaitMaxInSessions
The new registry entries are located in the following registry subkey:

HKEY_LOCAL_MACHINE\software\microsoft\msmq\parameters


Use the following table to configure the new registry entries:
Collapse this tableExpand this table
NameTypeValue description
MaxInSessionsDWORDThis value represents the actual number of sessions that Message Queuing lets connect at the same time. When this value is -1, or if the MaxInSessions new registry entry is not present, there is no change. The number of connections is not limited.
WaitMaxInSessionsDWORDThis value represents the time interval in milliseconds that Message Queuing waits until it verifies the number of active sessions. Message Queuing does this to verify whether new sessions can be accepted. This entry only applies if the MaxInSessions new registry entry is present, and the number-of-sessions limit is reached.

MORE INFORMATION

When Message Queuing diagnostic logging is enabled, Message Queuing logs the following message when Message Queuing stops accepting new sessions:
QM Error: sessmgr/376, Point


When Message Queuing resumes accepting new sessions, Message Queuing logs the following message:
QM Error: sessmgr/377, Point

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

REFERENCES

For additional information about how hotfix packages are named, click the following article number to view the article in the Microsoft Knowledge Base:
816915 New file naming schema for Microsoft Windows software update packages

Properties

Article ID: 870985 - Last Review: June 1, 2006 - Revision: 4.3
APPLIES TO
  • Microsoft Message Queuing 2.0
Keywords: 
kbbug kbfix kbqfe kbwin2000presp5fix kbhotfixserver KB870985

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