Microsoft KB Archive/885904

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

Article ID: 885904

Article Last Modified on 10/25/2007

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APPLIES TO


 * Microsoft Exchange Server 2003 Standard Edition
 * Microsoft Exchange Server 2003 Enterprise Edition

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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.



Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

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 1236 Event Source: MSExchangeIS

Event Category: General

Event ID: 1236

Event Type: Warning

Description: Publication of a notification  to   subscribers (  estimated) of folder   in database &quot; &quot; succeeded, but took an abnormally long time (  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 1237 Event Source: MSExchangeIS

Event Category: General

Event ID: 1237

Event Type: Error

Description: Publication of a notification  to   subscribers (  estimated) of folder   in database &quot; &quot; failed with error , and took an abnormally long time (  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 1238 Event Source: MSExchangeIS

Event Category: General

Event ID: 1238

Event Type: Warning

Description: Enumeration of  entries for the ACL of folder   in database &quot; &quot; succeeded, but took an abnormally long time (  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 1239 Event Source: MSExchangeIS

Event Category: General

Event ID: 1238

Event Type: Error

Description: Enumeration of  entries for the ACL of folder   in database &quot; &quot; failed with error %5, and took an abnormally long time (  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:

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:

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 &quot;Applies to&quot; 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

Additional query words: XADM

Keywords: kbqfe kbhotfixserver kbfix kbbug KB885904

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