Users experience a slow response when they access public folders on a computer that is running Exchange Server 2003 (885904)


The information in this article applies to:

  • Microsoft Exchange Server 2003 Standard Edition
  • Microsoft Exchange Server 2003 Enterprise Edition
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

SYMPTOMS

On a computer that is running Microsoft Exchange Server 2003, you may experience both of the following symptoms:
  • When users access public folders, they experience a slow response from the Exchange 2003 computer.
  • If you monitor the performance of the Exchange computer, you notice that repeated remote procedure call (RPC) usage spikes occur. RPC requests are high, but RPC operations per second are low.

CAUSE

This problem may occur if all the following conditions are true:
  • You have a public folder structure where many child public folders are created under a single parent public folder.
  • Each child public folder has its own access control list (ACL) entries defined.
When each child public folder has its own ACL entries defined, every time that the Exchange 2003 computer receives a new public folder replication message, the ACL for the parent public folder must be evaluated to determine which users have rights to see the changes to the parent public folder. If the parent public folder has a large discretionary access control list (DACL) entry, it may take a long time to update the view for each public folder subscriber.

Note The DACL for the parent folder is made up of the sum of the DACLs of all the child public folders.

If you have many child public folders under a single parent public folder, and if each of those child public folders has its own ACL defined, you may have many megabytes (MB) of DACL data that must be parsed. This data must be parsed so that the display can be updated for all the public folder subscribers every time that a public folder replication message is received.

RESOLUTION

Hotfix information

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft Exchange Server 2003 service pack that contains this hotfix.

To resolve this problem immediately, 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

Because of file dependencies, this hotfix requires Microsoft Exchange Server 2003 Service Pack 1 (SP1). For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

836993 How to obtain the latest service packs for Exchange Server 2003

Restart requirement

You do not have to restart your computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) 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
-------------------------------------------------------------- 
29-Oct-2004  01:06  6.5.7232.48     3,261,952  Mdbmsg.dll       
08-Oct-2004  02:12                      3,304  Redir.asp
29-Oct-2004  01:40  6.5.7232.48     5,144,064  Store.exe

Hotfix installation information

After you install this hotfix, four new events are logged to notify you if both of the following behaviors occur:
  • DACL enumeration takes longer than expected. By default, this event is logged if DACL enumeration takes 20 seconds or longer.
  • The publication of public folder notification messages takes longer than expected. By default, this event is logged if notification publication takes 60 seconds or longer.
In this scenario, one or more of the following events are logged:

Event ID 1236Event Source: MSExchangeIS
Event Category: General
Event ID: 1236
Event Type: Warning
Description: Publication of a notification notification to n subscribers (n estimated) of folder folderName in database "DatabaseName" succeeded, but took an abnormally long time (Number of seconds) to complete. This latency may be indicative of the notified folder or its parent having too many child folders with differing access rights. It may also be indicative of performance problems with your hardware.

Event ID 1237Event Source: MSExchangeIS
Event Category: General
Event ID: 1237
Event Type: Error
Description: Publication of a notification notification to n subscribers (n estimated) of folder folderName in database "databaseName" failed with error errorCode, and took an abnormally long time (NumberOf seconds) to do so. This latency may be indicative of the notified folder or its parent having too many child folders with differing access rights. It may also be indicative of performance problems with your hardware.

Event ID 1238Event Source: MSExchangeIS
Event Category: General
Event ID: 1238
Event Type: Warning
Description: Enumeration of numberOf entries for the ACL of folder folderName in database "databaseName" succeeded, but took an abnormally long time (numberOf seconds) to complete. This latency may be indicative of the folder having too many child folders with differing access rights. It may also be indicative of performance problems with your hardware.

Event ID 1239Event Source: MSExchangeIS
Event Category: General
Event ID: 1238
Event Type: Error
Description: Enumeration of numberOf entries for the ACL of folder folderName in database "databaseName" failed with error %5, and took an abnormally long time (numberOf seconds) to do so. This latency may be indicative of the folder having too many child folders with differing access rights. It may also be indicative of performance problems with your hardware.

You can control the default times that these events are triggered in by modifying the following registry subkeys:
  • To change the DACL enumeration threshold, modify the value in the following registry subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

    Value name: Abnormal OFLIST Enumerate Latency Threshold
    Value type: REG_DWORD
    Value data: 20000 (default)

  • To change the public folder notification message publication threshold, modify the value in the following registry subkey:

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

    Value name: Abnormal Publish Latency Threshold
    Value type: REG_DWORD
    Value data: 60000 (default)

These registry values must be specified in milliseconds.  If both of these registry subkeys do not exist, or if the value is 0 (zero) or is a negative value, the default value is used.

WORKAROUND

To work around this problem, change your public folder hierarchy so that less child public folders appear under each parent public folder. We recommend that you reduce the number of child public folders that appear under each parent public folder to 250 or less.

STATUS

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

MORE INFORMATION

For additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

817903 New naming schema for Exchange Server software update packages

Modification Type:MinorLast Reviewed:6/1/2006
Keywords:kbQFE kbHotfixServer kbfix kbBug KB885904 kbAudITPRO
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