FIX: CPU utilization of a CPU in a single node increases to 100 percent when you use SQL Server 2005 on a multiprocessor computer that uses NUMA architecture

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Article ID: 948450 - View products that this article applies to.
Bug #: 50002304 (SQL Hotfix)
Microsoft distributes Microsoft SQL Server 2005 fixes as one downloadable file. Because the fixes are cumulative, each new release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2005 fix release.
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SYMPTOMS

You install SQL Server 2005 on a multiprocessor computer that uses non-uniform memory access (NUMA) architecture. CPU utilization of a CPU in a single node increases to 100 percent. If you query the sys.dm_exec_requests system table, you find that a row has a value of LAZY WRITER in the command column. If you query this table repeatedly while this problem occurs, you notice that the value of the CPU column of the row constantly increases even though no query is running.

CAUSE

This problem occurs because SQL Server 2005 incorrectly identifies how to use the buffer pool memory. When SQL Server 2005 uses the buffer pool memory, a lazy writer thread enters an infinite loop and uses lots of CPU resources. Any lazy writer thread increases the CPU utilization because the lazy writer threads all wake up every one second. When this problem occurs, the CPU utilization is high even if SQL Server is expected to be in an idle state.

RESOLUTION

The fix for this issue was first released in Cumulative Update 7. For more information about how to obtain this cumulative update package for SQL Server 2005 Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
949095 Cumulative update package 7 for SQL Server 2005 Service Pack 2
Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2005 fix release. Microsoft recommends that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
937137 The SQL Server 2005 builds that were released after SQL Server 2005 Service Pack 2 was released
Microsoft SQL Server 2005 hotfixes are created for specific SQL Server service packs. You must apply a SQL Server 2005 Service Pack 2 hotfix to an installation of SQL Server 2005 Service Pack 2. By default, any hotfix that is provided in a SQL Server service pack is included in the next SQL Server service pack.

WORKAROUND

To work around this problem, disable NUMA by enabling trace flag 8015 when the SQL Server service starts.

STATUS

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

MORE INFORMATION

For more information about what files are changed, and for information about any prerequisites to apply the cumulative update package that contains the hotfix that is described in this Microsoft Knowledge Base article, click the following article number to view the article in the Microsoft Knowledge Base:
949095 Cumulative update package 7 for SQL Server 2005 Service Pack 2

Important information for SQL Server 2005 Analysis Services

A known issue exists in Cumulative Update 7 for SQL Server 2005 Analysis Services. Consider the following scenario. You install Cumulative Update 7 for SQL Server 2005 SP2. In SQL Server Profiler, you start a trace or stop a trace. Then, you run a query. The execution time of the query exceeds the value of the ForceCommitTimeout server setting. In this scenario, all the queries that are running on the server are canceled. To work around this issue, do not run MDX queries before you start a trace or stop a trace.

REFERENCES

For more information about the list of builds that are available after SQL Server Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
937137 The SQL Server 2005 builds that were released after SQL Server 2005 Service Pack 2 was released
For more information about the Incremental Servicing Model for SQL Server, click the following article number to view the article in the Microsoft Knowledge Base:
935897 An Incremental Servicing Model is available from the SQL Server team to deliver hotfixes for reported problems
For more information about how to obtain SQL Server 2005 Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:
913089 How to obtain the latest service pack for SQL Server 2005
For more information about the new features and the improvements in SQL Server 2005 Service Pack 2, visit the following Microsoft Web site:
http://go.microsoft.com/fwlink/?LinkId=71711
For more information about the naming schema for SQL Server updates, click the following article number to view the article in the Microsoft Knowledge Base:
822499 New naming schema for Microsoft SQL Server software update packages
For more information about software update terminology, 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

Properties

Article ID: 948450 - Last Review: May 6, 2008 - Revision: 2.2
APPLIES TO
  • Microsoft SQL Server 2005 Standard Edition
  • Microsoft SQL Server 2005 Developer Edition
  • Microsoft SQL Server 2005 Enterprise Edition
  • Microsoft SQL Server 2005 Standard X64 Edition
  • Microsoft SQL Server 2005 Standard Edition for Itanium-based Systems
  • Microsoft SQL Server 2005 Enterprise X64 Edition
  • Microsoft SQL Server 2005 Enterprise Edition for Itanium-based Systems
Keywords: 
kbsql2005engine kbhotfixrollup kbfix kbpubtypekc kbqfe kbexpertiseadvanced KB948450

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