FIX: Intermittent error message and assertion failure when you use database mirroring in SQL Server 2005, in SQL Server 2008, or in SQL Server 2008 R2: "SQL Server Assertion: File: <loglock.cpp>, line=823 Failed Assertion = 'result == LCK_OK'"

You set up a database mirroring between two computers that are running SQL Server 2005, SQL Server 2008, or SQL Server 2008 R2. In this scenario, you experience the following symptoms intermittently:

• The database mirroring is broken and the database mirroring session enters the SUSPENDED state.
• A mini-dump file is generated in the SQL Server log folder.
• An assertion failure occurs and the following error message is logged in the SQL Server error log file on the mirror server.
  <Date><Time> <spid> Error: 17066, Severity: 16, State: 1.
  <Date><Time> <spid> SQL Server Assertion: File: <loglock.cpp>, line=823 Failed Assertion = 'result == LCK_OK'. This error may be timing-related. If the error persists after rerunning the statement, use DBCC CHECKDB to check the database for structural integrity, or restart the server to ensure in-memory data structures are not corrupted.
  <Date><Time> <spid> Error: 3624, Severity: 20, State: 1.
  <Date><Time> <spid> A system assertion check has failed. Check the SQL Server error log for details. Typically, an assertion failure is caused by a software bug or data corruption. To check for database corruption, consider running DBCC CHECKDB. If you agreed to send dumps to Microsoft during setup, a mini dump will be sent to Microsoft. An update might be available from Microsoft in the latest Service Pack or in a QFE from Technical Support.
  <Date><Time> <spid> Error: 1454, Severity: 16, State: 1.
  <Date><Time> <spid> While acting as a mirroring partner for database '<Database>', server instance '<Instance>' encountered error 3624, status 1, severity 20. Database mirroring will be suspended. Try to resolve the error and resume mirroring.
  <Date><Time> <spid> Database mirroring is inactive for database '<database name>'. This is an informational message only. No user action is required.
  <Date><Time> <spid> Using 'dbghelp.dll' version '4.0.5'
  <Date><Time> <spid> **Dump thread - spid = <spid>, PSS = 0x00000009727F8B60, EC = 0x00000006990601C0
  <Date><Time> <spid> ***Stack Dump being sent to C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\LOG\SQLDump0071.txt
  <Date><Time> <spid> *
  *******************************************************************************
  <Date><Time> <spid> *
  <Date><Time> <spid> * BEGIN STACK DUMP:
  <Date><Time> <spid> * <Date><Time> <spid>
  <Date><Time> <spid> *
  <Date><Time> <spid> * Location: loglock.cpp:823
  <Date><Time> <spid> * Expression: result == LCK_OK
  <Date><Time> <spid> * SPID: <spid>
  <Date><Time> <spid> * Process ID: 6792

Note You must reinitialize mirroring to resolve this issue and to resume the mirroring of this database.

When the SQL Server database engine is applying transaction logs on the mirror server, a lock escalation occurs. However, an error that occurs with the logging operation prevents the lock escalation from releasing some page locks. Therefore, the assertion occurs.

SQL Server 2005 Service Pack 3

The fix for this issue was first released in Cumulative Update 6 for SQL Server 2005 Service Pack 3. For more information about this cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base: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. We recommend 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: Microsoft SQL Server 2005 hotfixes are created for specific SQL Server service packs. You must apply a SQL Server 2005 Service Pack 3 hotfix to an installation of SQL Server 2005 Service Pack 3. By default, any hotfix that is provided in a SQL Server service pack is included in the next SQL Server service pack.

The release version of SQL Server 2008

Important You must install this fix if you are running the release version of SQL Server 2008.

The fix for this issue was first released in Cumulative Update 8. For more information about how to obtain this cumulative update package for SQL Server 2008, click the following article number to view the article in the Microsoft Knowledge Base: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 2008 fix release. We recommend 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:

SQL Server 2008 Service Pack 1

Important You must install this fix if you are running SQL Server 2008 Service Pack 1.

The fix for this issue was first released in Cumulative Update 5 for SQL Server 2008 Service Pack 1. For more information about this cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base: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 2008 fix release. We recommend 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: Microsoft SQL Server 2008 hotfixes are created for specific SQL Server service packs. You must apply a SQL Server 2008 Service Pack 1 hotfix to an installation of SQL Server 2008 Service Pack 1. By default, any hotfix that is provided in a SQL Server service pack is included in the next SQL Server service pack.

SQL Server 2008 R2

Important You must install this fix if you are running SQL Server 2008 R2.

The fix for this issue was first released in Cumulative Update 1. For more information about how to obtain this cumulative update package for SQL Server 2008 R2, click the following article number to view the article in the Microsoft Knowledge Base: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 2008 R2 fix release. We recommend 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:

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

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: For more information about how to obtain the latest service pack for SQL Server 2005, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to obtain the latest service pack for SQL Server 2008, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to obtain the latest service pack for SQL Server 2008 R2, click the following article number to view the article in the Microsoft Knowledge Base: 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: For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: