BUG: Memory Leak with DB-Library Connection Using TCP/IP or IPX/SPX

ID: Q236439

The information in this article applies to:

Microsoft SQL Server version 7.0

BUG #: 55725 (SQLBUG_70)

SYMPTOMS

A memory leak can occur after opening a DB-Library connection when the application is using the TCP/IP or IPX/SPX network libraries. This leak persists for each connection to SQL Server through DB-Library even after the connection is closed.

RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next SQL Server service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp

The English version of this fix should have the following file attributes or later:


   Version       File name        Platform
   ---------------------------------------
   7.00.702      S70702i.exe      Intel
                 S70702a.exe      Alpha

NOTE: Due to file dependencies, the most recent hotfix or feature that contains the above files may also contain additional files.

NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, and if it is determined that you only require the fix you requested, no fee will be charged. However, if you request additional technical support, and if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support, you may be charged a non-refundable fee.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:

Q154871 Determining If You Are Eligible for No-Charge Technical Support

WORKAROUND

To work around this problem, do either of the following:

Keep a single connection open when using DB-Library.

-or-

Use a different network library, such as named pipes or multiprotocol.

STATUS

Microsoft has confirmed this to be a problem in SQL Server version 7.0.

MORE INFORMATION

The memory leak is roughly 4 KB for each DB-Library connection opened to the server.

This problem is specific to the use of the 32-bit DB-Library API, and the problem only occurs when using the TCP/IP or IPX/SPX network libraries.

For an application that uses a single DB-Library connection, the memory leak will hardly be noticeable. But for applications that either connect/disconnect for each query ("make/break connections") or use multiple connections, the problem can be more severe, causing all of the memory on the computer to be consumed.

Additional query words: db lib dblib net netlib multi protocol


Keywords          : SSrvDB_Lib kbbug7.00 
Version           : winnt:7.0
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: July 6, 1999