Microsoft KB Archive/293836

= Information Store performance degradation caused by excessive scanning in ESE =

Article ID: 293836

Article Last Modified on 10/26/2006

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APPLIES TO


 * Microsoft Exchange Server 5.5 Standard Edition

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This article was previously published under Q293836





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
The Microsoft Exchange Information Store process may perform poorly, CPU utilization may be high for the Information Store process, and one or more of the following error messages may be logged in the Microsoft Windows NT Event Viewer Application event log:

Message 1
Event ID: 1101

Source: MSExchange Private

Type: Error

Description: Error 0xfffffbd3 occurred on message 1-EB1F8B1 during a background cleanup

Message 2
Event ID: 160

Source: ESE97

Type: Warning

Description:

MSExchangeIS (359) Background clean-up skipped pages. Database may benefit from online or offline defragmentation.

If you create a User.dmp file of the Store.exe process when the Information Store service is in this state, the User.dmp file is similar to the following stack frames:

ChildEBP RetAddr Args to Child 315feef4 6febd4a8 00000001 00000000 fffffa01 ESE!FCB__ErrAlloc_+0x3a4 315fef0c 6fe9d983 0027e1bb 315fef30 00000001 ESE!FCB__ErrCreate+0x16 315fef40 6fe9159d 00000001 315fef68 00000000 ESE!ErrBTIOpen+0x4d 315fef50 6fe9e703 00000001 315fef68 00000000 ESE!ErrBTOpen+0x14 315fef60 6febf962 00000001 315fef88 315ff0f8 ESE!ErrDIROpen+0x11 315ff030 6febe46a 006832d8 162eef60 1497fc70 ESE!ErrCATIInitIndexFCBs+0x4a6 315ff0d4 6fe9e581 006832d8 00000000 315ff1fc ESE!ErrCATInitFCB+0x2c4 315ff120 78021365 315ff138 0065d33e 315ff174 ESE!ErrFILEOpenTable+0x3f8 315ff140 6fe9e171 315ff160 00000000 00060000 MSVCRT!Ordinal206+0x195f1 315ff160 6fe9e03f 315ff1fc 315ff200 00060000 ESE!ErrIsamOpenTable+0xa5 00000001 00000000 00000000 00000000 00000000 ESE!JetOpenTable+0x140

This thread scans the (last recently used list) LRU and continues to do so over and over again, while holding on to a critical section that other Extensible Storage Engine (ESE) threads need, as shown in the following stack:

ChildEBP RetAddr Args to Child 396ef888 77f6ce61 000012bc 00000000 00000000 ntdll!NtWaitForSingleObject+0xb 396ef8fc 77f67586 6ff40b18 6fe9cf7d 6ff40b18 ntdll!RtlpWaitForCriticalSection+0xaa 396ef904 6fe9cf7d 6ff40b18 00000001 17074a60 ntdll!RtlEnterCriticalSection+0x46 396ef928 6fe91532 17074a60 6fe9ce5a 00000000 ESE!FCB__Unlink+0x10c 396ef930 6fe9ce5a 00000000 17074a60 396ef958 ESE!FCBUnlink+0x9 396ef944 6fe9d1ab 16629e40 17074a60 17074a60 ESE!BTClose+0x109 396ef958 6fe9d489 00665154 00000096 396ef9cc ESE!DIRClose+0x89 396ef970 6fe9ec90 260ca320 6fe9ecd5 00665154 ESE!ErrFILECloseTable_245+0xb 396ef978 6fe9ecd5 00665154 260ca320 00000000 ESE!ErrIsamCloseTable+0x3c 00665164 00656c62 4241544a 5341425f 453a3a45 ESE!JetCloseTable+0x43 00665238 00644967 4241544a 5341425f 453a3a45 store!HrAppendTextToCompressedRTF+0x262



CAUSE
This problem can occur if the information store sets the Max Open Tables and Preferred Max Open Tables values (which regulate the number of Open Tables in the JET database) incorrectly when the information store starts. The calculation to set these values is dependent upon many things and is very complex. The Preferred Max Open Tables value is always set lower than the Max Open Tables value. If the information store reaches the value set by the Preferred Max Open Tables value, JET starts a scan to try to find resources that can be used to comply with more requests for open tables. This scan repeats aggressively, which results in the degradation of the information store process.



RESOLUTION
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 5.5 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. The English version of this fix should have the following file attributes or later:

Component: Information Store

Note Because of file dependencies, this fix requires Microsoft Exchange Server version 5.5 Service Pack 4. Important If you do not install this hotfix, the Exchange databases can grow very quickly because the background-cleanup thread goes into an infinite loop with the Match Open Tables problem.



STATUS
Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5.



MORE INFORMATION
To resolve this problem in Exchange Server 5.5, the Preferred Max Open Tables value must be set equal to the Max Open Tables value when the Information Store service starts. This key must be manually added and set to any value other than zero so that the Information Store service automatically sets the Preferred Max Open Tables value equal to the Max Open Tables value.



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.

To add the registry key:  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: Match Max Open Tables

Data type: REG_DWORD

Radix: Hexadecimal

Value data: 0x1

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

Additional query words: Store.exe XADM

Keywords: kbhotfixserver kbqfe kbbug kbexchange550presp5fix kbfix kbqfe KB293836

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