Microsoft KB Archive/328906

= XADM: Access Control List Upgrades Cause Slow Public Folder Performance; Fix Requires Exchange 2000 SP3 =

Article ID: 328906

Article Last Modified on 2/20/2007

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APPLIES TO


 * Microsoft Exchange 2000 Server Standard Edition

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This article was previously published under Q328906





SYMPTOMS
If you try to gain access to public folders on an Exchange 2000 server, you may experience a long delay when you try to expand the hierarchy of folders. During this delay, you may receive an RPC wait dialog box (depending on the version of Microsoft Outlook that you are using) that states the name of the server that contains the data that you are trying to access (which should be the Exchange 2000 public folder server).

This problem is most likely to occur in a mixed Microsoft Exchange Server version 5.5 and Exchange 2000 environment in which public folders are being migrated. In all cases, the clients point to Exchange 2000 public folder servers for hierarchy requests.



CAUSE
The access control list (ACL) must be upgraded when public folders and the public folder hierarchy object are migrated. That upgrade integrates the ACL with Microsoft Windows 2000 Active Directory. During the upgrade, the Exchange 2000 information store must contact a Windows 2000 domain controller to look up user accounts that are in the ACL list.

This problem may occur if the information store process makes too many calls to the domain controllers to obtain information. Other threads that are performing operations in the information store stop while they wait for such lookup calls to return. This creates a thread backlog and degrades performance.



Cumulative Patch Information
To resolve this problem, obtain the March 2003 Exchange 2000 Server Post-Service Pack 3 (SP3) Rollup. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

813840 XGEN: March 2003 Exchange 2000 Server Post-Service Pack 3 Rollup

Hotfix Information
To resolve this problem, obtain the Microsoft Exchange 2000 Server Post-Service Pack 3 MDB patch. For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

329882 XGEN: Exchange 2000 Server Post-Service Pack 3 MDB Fixes Available



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



MORE INFORMATION
After you apply this fix, the information store creates a cache that contains the Microsoft Windows NT Security Identifier (SID) and indicates whether or not the SID is a user object or group object.

This cache is created and populated when a public folder is first touched. After the cache is populated, all calls to look up account SIDs are first directed to the information store cache. If the SID is not in the information store cache, the call is made to the domain controller, and then the information for that SID is added to the cache.

By default, the cache is maintained for one hour. If the cache exceeds the default 8 megabytes (MB) of entries, older cache entries are removed to make room for the new entries.

You can use registry keys to adjust both the default cache time and the default cache size. Microsoft recommends that you do not change these default settings unless there you have evidence that doing so will increase performance.

To change the default SID cache expiry time (in milliseconds):  Start Registry Editor (Regedt32.exe). Locate and then click the following key in the registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

 On the Edit menu, click Add Value, and then add the following registry value:

Value name: Lookup Sid Cache Expire

Data type: REG_DWORD

Radix: Hexadecimal

Value data: The minimum value is 0x0. The maximum value is 0x5460 (six hours).

 Quit Registry Editor.</ol>

To change the default SID cache size (the number of items): <ol> Start Registry Editor (Regedt32.exe).</li> Locate and then click the following key in the registry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

</li> On the Edit menu, click Add Value, and then add the following registry value:

Value name: Lookup Sid Cache Size

Data type: REG_DWORD

Radix: Hexadecimal

Value data: The minimum value is 0x400 (1,024 KB). The maximum value is 0x8000 (32,768 KB).

</li> Quit Registry Editor.</li></ol>

Additional query words: kbExchange2000preSP4mdbFix PF DC kbExchange2000preSP4marchbarFix

Keywords: kbhotfixserver kbqfe kbbug kbexchange2000presp4fix kbfix kbqfe KB328906

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