ACC2000: "File Sharing Lock Count" Error During Synchronization

• Microsoft Access 2000

SYMPTOMS

When you synchronize two replicas, you may receive the following error message:

Synchronization between '<Replica1.mdb>' and '<Replica2.mdb>' failed.

File sharing lock count exceeded (Error 3052).

CAUSE

A member of the replica set contains too many changes for synchronization to be completed successfully. For example, if one of the replicas has increased in size by 100 megabytes (MB) because you have added a large number of new records, you may receive this error. The replica that contains too many changes may be the database from which you are trying to synchronize, or it may be another member of the replica set.

RESOLUTION

In Microsoft Access 2000, you can take advantage of a feature that allows you to increase the MaxLocksPerFile setting for Microsoft Jet database engine 4.0 by editing the Windows Registry. The default value of this setting is 9500. However, changing this value is not recommended if one of the replicas is located on a Novell Netware server, because the server's maximum record locks per connection is 10000. If both replicas are located on servers running Microsoft Windows NT 4.0 or Microsoft Windows 95 or later, the maximum value of this setting is limited only by available resources.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

1. Quit Microsoft Access.



2. Click Start and then click Run.



3. In the Open box, type regedit.



4. Locate the HKEY_LOCAL_MACHINE registry folder.



5. Expand HKEY_LOCAL_MACHINE until you locate the SOFTWARE\Microsoft\Jet\4.0\Engines\Jet 4.0 folder.



6. Click on the Jet 4.0 folder to view its contents.



7. Select the MaxLocksPerFile entry; on the Edit menu, click Modify.



8. In the Edit DWORD Value dialog box, select Decimal and increase the number in the Value Data box.



9. Click OK to save the MaxLocksPerFile setting.



10. Quit the Registry Editor.



11. Start Microsoft Access and synchronize the replicas.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

The MaxLocksPerFile setting allows the Microsoft Jet database engine to complete large transactions without exceeding a specified record lock limit. Instead of exceeding this limit, the Jet database engine splits a transaction into two or more parts; after one part has been committed, the Jet database engine frees the locks so that they can be reused. As a result, fewer locks are required to complete the transaction. This prevents a Novell Netware server, which limits the maximum record locks per connection to 10000, from crashing when that value is exceeded.

However, the Jet database engine does not split the transaction when it synchronizes two replicas. If the transaction cannot be completed within the limit specified in the MaxLocksPerFile setting unless it is split into parts, you receive the error described in the "Symptoms" section, and the synchronization does not occur.

Steps to Reproduce Problem

1. Start Microsoft Access and open a new blank database.



2. Create the following table:
   
   

   Field Name	Data Type	Field Size
   ID	Number	Long Integer
   Field1	Text	50
   Field2	Text	50
   Field3	Text	50
   Field4	Text	50




3. Save the table as tblTable1. When asked if you want to create a primary key, click No.



4. On the Tools menu, point to Replication, and click Create Replica. When prompted to close the database, click Yes. When prompted to make a backup, click No.



5. In the Location of New Replica dialog box, note the location and file name of the new replica. Click OK.



6. Click OK when prompted that the Design Master was successfully created.



7. Open a new, blank module.



8. On the Tools menu, click References.



9. Scroll down through the Available References and click to select the check box for the Microsoft DAO 3.6 Object Library. Then click OK.



10. Type the following procedure:




Function Filler(lngNumRecs As Long)
    Dim lngLoopCount As Long
    Dim strFillerString As String
    Dim db As Database
    Dim rs As Recordset

    strFillerString = ""

    For lngLoopCount = 1 To 40
        strFillerString = strFillerString & "x"
    Next lngLoopCount

    Set db = CurrentDb
    Set rs = db.OpenRecordset("tblTable1")

    For lngLoopCount = 1 To lngNumRecs
        rs.AddNew
        rs![ID] = lngLoopCount
        rs![Field1] = strFillerString
        rs![Field2] = strFillerString
        rs![Field3] = strFillerString
        rs![Field4] = strFillerString
        rs.Update
    Next lngLoopCount

    db.Close
    MsgBox "Process Completed."
End Function 

11. Save the module as Module1. Type the following line in the Immediate window, and then press ENTER:

    
    ?Filler(500000) 

    NOTE: This procedure may take a long time to run and may require as much as 400 MB of free disk space. After the process has completed, continue on to the next step.



12. On the Tools menu, point to Replication, and then click Synchronize Now.



13. In the Synchronize Database '<name>' dialog box, click OK.



14. Click Yes to close the database and begin synchronization.

REFERENCES

For more information about MaxLocksPerFile setting, click Microsoft Access Help on the Help menu, type "Initializing the Microsoft Jet 4.0 Database Engine Driver" in the Office Assistant or the Answer Wizard, and then click Search to view the topic.

For additional information about replication, please see the following article in the Microsoft Knowledge Base:

Q214534 Jet 4.0 Replication White Paper Available on MSL

Additional query words: buffer

Keywords          : kberrmsg kbdta GnlOthr RplGen 
Version           : WINDOWS:2000
Platform          : WINDOWS 
Issue type        : kbbug 

Last Reviewed: July 13, 1999