Express message throughput slows over time in Message Queuing (311583)



The information in this article applies to:

  • Microsoft Message Queuing 2.0

This article was previously published under Q311583
Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry

SYMPTOMS

Over a given period, the amount of time required to send express messages or read express messages may increase by 90 percent or more.

CAUSE

This behavior can occur if message files become fragmented. This fragmentation significantly impedes access to those files.

RESOLUTION

This fix allows a workaround in a scenario in which most messages vary in size between two close values -- for example, where body size ranges between 500 and 1000 bytes.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
The fix adds the following DWORD registry value, which forces the driver to allocate a minimum number of bytes for each packet:

HKEY_LOCAL_MACHINE\Software\Microsoft\MSMQ\Parameters\MinimumAllocation

This value must include MSMQ headers as well. When no options are set, a Microsoft Message Queuing header is typically in the range of 160 to 200 bytes. In the preceding scenario, if you don't use encryption and authentication, a value of 1200 is sufficient.

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site: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 typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English-language version of this fix should have the following file attributes or later:
   Date           Time  Version    Size    File name     
   -------------------------------------------------------
   02/28/2001   17:54  5.0.0.720    273kb  mq1repl.dll
   02/28/2001   17:47  5.0.0.720     14kb  mq1sync.dll
   02/28/2001   17:47  5.0.0.733     70kb  mqac.sys
   02/28/2001   17:54  5.0.0.721    210kb  mqads.dll
   02/28/2001   17:47  5.0.0.720     22kb  mqbkup.exe
   02/28/2001   17:54  5.0.0.720     29kb  mqcertui.dll
   02/28/2001   17:54  5.0.0.720     49kb  mqclus.dll
   02/28/2001   17:54  5.0.0.720     30kb  mqdbodbc.dll
   02/28/2001   17:54  5.0.0.720     74kb  mqdscli.dll
   02/28/2001   17:54  5.0.0.720     41kb  mqdssrv.dll
   02/28/2001   17:47  5.0.0.720     96kb  mqmig.exe
   02/28/2001   17:54  5.0.0.720    258kb  mqmigrat.dll
   02/28/2001   17:54  5.0.0.720    219kb  mqoa.dll
   02/28/2001   17:54  5.0.0.720      8kb  mqperf.dll
   02/28/2001   17:54  5.0.0.733    406kb  mqqm.dll
   02/28/2001   17:54  5.0.0.720      9kb  mqrperf.dll
   02/28/2001   17:54  5.0.0.733     90kb  mqrt.dll
   02/28/2001   17:54  5.0.0.720     69kb  mqsec.dll
   02/28/2001   17:54  5.0.0.720    391kb  mqsnap.dll
   02/28/2001   17:48  5.0.0.720     14kb  mqsvc.exe
   02/28/2001   17:54  5.0.0.720     24kb  mqupgrd.dll
   02/28/2001   17:54  5.0.0.720    106kb  mqutil.dll
   02/28/2001   17:54  5.0.0.720     64kb  msmq.cpl
   02/28/2001   17:54  5.0.0.720    156kb  msmqocm.dll
				

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

Modification Type:MinorLast Reviewed:10/6/2005
Keywords:kbprb kbQFE KB311583