Microsoft KB Archive/831652

= FIX: A query on a real-time cube may block real-time updates for other cubes =

Article ID: 831652

Article Last Modified on 11/21/2006

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APPLIES TO


 * Microsoft SQL Server 2000 Analysis Services
 * Microsoft SQL Server 2000 Analysis Services

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Bug #: 14180 (Plato7x)



SYMPTOMS
If a server that is running Microsoft SQL Server 2000 Analysis Services has more than one cube with real-time updates enabled, a long running Multidimensional Expression (MDX) for one real-time enabled cube might block the processing of real-time updates for other real-time enabled cubes.



CAUSE
This problem occurs because Analysis Services processes real-time update notifications sequentially. To flush the cache for a cube, the server that is running Analysis Services must obtain a write lock on the real-time enabled cube. If another process such as an MDX query currently has a read lock on the cube, the server must wait for the current locks to be released before it grants the write lock and continues with the cache flush operation for the cube. Analysis Services uses a single thread to perform cache flush operations on real-time enabled cubes. Therefore, if update notifications are received from SQL Server for two real-time enabled cubes, Analysis Services will perform the cache flush operations for these cubes sequentially. If the write lock cannot be obtained for the first real-time cube, the thread waits for the write lock. The notification for the second cube is queued behind the waiting write lock and it cannot be processed until the cache flush operation is completed for the first cube.



Service pack information
To resolve this problem, obtain the latest service pack for Microsoft SQL Server 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

290211 How to obtain the latest SQL Server 2000 service pack

Hotfix information
The English version of this fix has the file attributes (or later) 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 --  03-Nov-2003  17:08  8.0.874.0         217,668  Msmdcb80.dll 28-Oct-2003 02:58  8.0.0.872       4,059,716  Msmddo80.dll 03-Nov-2003 17:08  8.0.874.0       1,032,768  Msmdgd80.dll 28-Oct-2003 02:58  8.0.823.0         172,608  Msmdpump.dll 28-Oct-2003 02:58  8.0.0.864       9,638,468  Msmdsgn80.dll 03-Nov-2003 17:08  8.0.874.0       1,835,588  Msmdsrv.exe 03-Nov-2003 17:08  8.0.874.0       2,077,264  Msolap80.dll 10-May-2003 08:05  8.0.820.0         213,069  Msolap80.rll Note Because of file dependencies, the most recent hotfix or feature that contains these files may also contain additional files.

SQL Server 2000 Analysis Services 64-bit
For additional information about a hotfix build that is designed for a server that is running SQL Server 2000 Analysis Services 64-bit or to find out if a fix is scheduled to be included in SQL Server 2000 Analysis Services 64-bit Service Pack 4, click the following article number to view the article in the Microsoft Knowledge Base:

831653 Availability of Analysis Services 2000 64-bit Hotfix Build



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section of this article.

This problem was first corrected in Microsoft SQL Server 2000 Service Pack 4.



MORE INFORMATION
After you apply the fix that is referred to in this article, the server that is running Analysis Services creates a new thread to handle the cache flushing operation if the write lock for the real-time enabled cube cannot be obtained immediately. The new thread then waits for the write lock to be granted, allowing the existing thread to continue to the next real-time cube cache flush request.

For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the Standard Terminology That Is Used to Describe Microsoft Software Updates

Keywords: kbbug kbfix kbqfe kbsqlserv2000presp4fix kbhotfixserver KB831652

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