FIX: Running Stack Dumper Causes Memory Leak of Virtual Bytes (299466)

SYMPTOMS

Stack dumps are diagnostic information that are used to troubleshoot problems. Stack dumps may occur when SQL Server encounters an exception or assertion, or explicitly when support engineers run certain diagnostics.

The generation of stack traces by SQL Server may result in a virtual byte memory leak. When SQL Server is installed on computers that have 2 gigabytes (GB), or more, of physical RAM, specific errors that indicate that virtual memory is low in the SQL Server process space may occur, depending on the frequency of the leak and the available virtual memory. Two examples of these error messages are:

SQL Server could not spawn process_loginread thread

-and-

WARNING: Clearing procedure cache to free contiguous memory.

Buffer Distribution: Stolen=3454 Free=2540 Procedures=138 Inram=0 Dirty=1108 Kept=35 I/O=0, Latched=0, Other=214821

Buffer Counts: Committed=222096 Target=222096 Hashed=215964 InternalReservation=547 ExternalReservation=0 Min Free=512

Procedure Cache: TotalProcs=8 TotalPages=138 InUsePages=138 Dynamic Memory Manager: Stolen=3556 OS=497 General=1706 Query Plan=755 Optimizer=0 Utilities=9 Connection=1583 Global Memory Objects: Resource=1119 Locks=163 XDES=1 SQLCache=90 Replication=5 LockBytes=2 ServerGlobal=20

Query Memory Manager: Grants=0 Waiting=0 Maximum=164370 Available=164370

RESOLUTION

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

290211 INF: How to Obtain the Latest SQL Server 2000 Service Pack

WORKAROUND

Rename the SQLImage.dll and DBGHelp.dll files in the \Binn folder for the SQL Server installation to different file names. If you are running on a Microsoft Windows 2000-based computer, this step is enough to avoid the problem.

If you are running on a Microsoft Windows NT 4.0-based computer, you also must replace the Imagehlp.dll and DBGHELP.dll files in %Systemroot%\System32 with the copies of these files from Windows 2000.

STATUS

Microsoft has confirmed that this is a problem in SQL Server 2000. This problem was first corrected in SQL Server 2000 Service Pack 1.

REFERENCES

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

278372 FIX: Running Stack Dumper Can Cause Memory Leak of Virtual Bytes