FIX: The internal connection pooling mechanism may repeatedly try to make new connections when an application uses the System.Data.SqlClient class to connect to a SQL Server database in Windows Server 2003 SP1

View products that this article applies to.

Bug #: 379637 (SQLBUDT)

SYMPTOMS

Consider the following scenario.

You are running Microsoft Windows Server 2003 Service Pack 1 (SP1).
An ADO.NET-based application uses the System.Data.SqlClient class to establish a new connection.
When an error occurs in the application, the internal connection pooling mechanism repeatedly tries to make a new connection every few minutes. This behavior occurs even if the application is not regularly requesting new connections.

In this scenario, you may experience one of the following symptoms:

When Microsoft SQL Server is not available for new connections and you run the application by using the Microsoft Visual Studio .NET 2003 Debugger, the following behavior occurs:
- The debugger pauses to run code.
- A message appears that states that an unhandled exception occurred. If the application has been defined to handle exception events, the exception will be caught by the event handler.
When SQL Server is available for new connections, no problem is visible.

If an exception occurs in the application, you may receive a database connection failure error message.

Note This problem does not occur in Microsoft Windows Server 2003.

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RESOLUTION

Service pack information

To resolve this problem, obtain the latest service pack for Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

889100 (http://support.microsoft.com/kb/889100/ ) How to obtain the latest service pack for Windows Server 2003

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Hotfix information

Prerequisites

To install this hotfix, you must have the .NET Framework 1.1 Service Pack 1 (SP1) installed on the computer.

Restart requirement

You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

Hotfix file information

The English version of this hotfix has the file attributes (or later file attributes) 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
   -------------------------------------------------------------
   27-Jul-2005  03:00  1.1.4322.2339  1,298,432  System.data.dll

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STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Server 2003 Service Pack 2.

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MORE INFORMATION

This problem is not included in the .NET Framework 1.1 SP1 base installation. This problem is introduced by the post-.NET Framework 1.1 SP1 fix that is described in the following Microsoft Knowledge Base article:

885445 (http://support.microsoft.com/kb/885445/ ) FIX: A computer that is running a .NET Framework 1.1 application experiences high CPU utilization when the application tries to connect to SQL Server 2000 by using the System.Data.SqlClient.SqlConnection.Open method

This problem does not occur on versions of the .NET Framework 1.1 that were installed before hotfix 885445 was applied. However, hotfix 885445 is included in the .NET Framework version that is installed with Windows Server 2003 SP1. Therefore, computers that have Windows Server 2003 SP1 installed automatically inherit the problem that is mentioned in the "Symptoms" section.

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

824684 (http://support.microsoft.com/kb/824684/ ) Description of the standard terminology that is used to describe Microsoft software updates

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