An Exchange Server 2003 computer that is configured as a public folder server may experience very poor performance

A Microsoft Exchange Server 2003 computer that is configured as a public folder server may experience very poor performance. When this problem occurs, one or more of the following problems may occur:

• Users are prompted to enter their Exchange credentials again.
• E-mail functionality slows.
• Users may lose their connection to the Exchange computer.
• Microsoft Outlook Address Book downloads may take longer than expected.

This problem may occur when slow domain controller responses cause a backlog of requests to reload the public folder hierarchy in the Microsoft Exchange Information Store service (Store.exe). The hierarchy should only be reloaded one time during an interval of time that is defined. This interval is typically 15 minutes. The symptoms that are described in this article occur because the time-out expires, and each client thread tries to reload the hierarchy.

The time-out value is not reset until the client thread receives a Lightweight Directory Access Protocol (LDAP) response from a domain controller. The response must contain the list of public folder servers. When the client thread receives the response, each client thread issues an LDAP request. If there are many users on your network, these LDAP requests could exhaust the 100 remote procedure call (RPC) requests that can be open at a time.

Hotfix information

A supported hotfix is 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 software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if 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. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

This hotfix requires Microsoft Exchange Server 2003 Service Pack 1.

Restart requirement

You do not have to restart your computer after you install 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.

If you apply the hotfix that is described in this article, you do not have to use this workaround. To work around this problem, configure the replication reload value to a 24-hour interval in the registry.

To configure the replication reload value in the registry, follow these steps.

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.

1. Click Start, click Run, type regedt32 in the Open box, and then click OK.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MsExchangeIS\<ServerName>\Public-(guid)
3. On the Edit menu, click Add Value.
4. In the Value Name box, type the following:
   Replication Reload TLH Min
5. In the Data Type list, click REG_DWORD, and then click OK.
6. In the Data box, type 86400, and then click OK.
   
   Note The value is the number of seconds between reloads. 86,400 seconds is equal to 24 hours.
7. Exit Registry Editor.

The replication value that you specify is only read when the public folder store starts. To force your Exchange Server 2003 computer to read the new value, dismount and then mount the public folder store. Do this after work hours when the load on the system is very light.

To dismount and then mount the public folder store, follow these steps:

1. Start Exchange System Manager.
2. Expand Servers, expand the server that you want, expand Storage_Group_Name, and then right-click Public Folder Store.
   
   Note If administrative groups are defined, follow these steps:
   1. Expand Administrative Groups.
   2. Expand Administrative_Group_Name.
   3. Expand Servers.
   4. Expand the server that you want.
   5. Expand Storage_Group_Name.
   6. Right-click Public Folder Store.
3. Click Dismount Store, and then click Yes to continue.
4. Right-click Public Folder Store, click Mount Store, and then click OK.

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

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