Article ID: 913176 - View products that this article applies to.
When you try to connect to a database by using the SqlConnection object in Microsoft ADO.NET 2.0, a connection failure may be reported even though the database server is actually available. This problem is most noticeable when the following conditions are true:
This problem occurs because of behavior that occurs when previous connection attempts to the server that is running Microsoft SQL Server fail. The SqlClient connection pool may internally throttle the number of new connection attempts to the server. This process is intended to occur for a short time. During this time, the connection pool automatically reports the last error that occurred instead of making a connection attempt to the server. After the time period has expired, the next connection request from the client application achieves a true connection to the server that is running SQL Server.
Note Sometimes, the time period can grow very large. This problem will depend on how long the database server is unavailable.
To resolve this issue, download the appropriate file for your computer:
For an x86-based computerThe following file is available for download from the Microsoft Download Center:
For an x64-based computerThe following file is available for download from the Microsoft Download Center:
For an Itanium-based computerThe following file is available for download from the Microsoft Download Center:
(http://download.microsoft.com/download/0/0/3/00392dd3-5b4f-4d99-94e8-6827b8f8d7ef/ndp20-kb916002-ia64.exe)For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.
(http://support.microsoft.com/kb/119591/ )How to obtain Microsoft support files from online services
To work around this problem, use the ClearPool or ClearAllPools methods of the SqlConnection object to reset the connection pool.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
After you apply this hotfix, a small delay may still occur before the client application can successfully connect to the database server when the database server recovers from an outage. Typically, this delay should not last more than 60 seconds, regardless of how long the SQL Server has previously been unavailable.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
824684For more information about the SqlConnection class, visit the following Microsoft Developer Network (MSDN) Web site:
(http://support.microsoft.com/kb/824684/ )Description of the standard terminology that is used to describe Microsoft software updates
http://msdn2.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection(VS.80).aspxThis hotfix is included in the same hotfix package as the hotfix in the following Microsoft Knowledge Base article:
(http://support.microsoft.com/kb/912151/ )FIX: The connection may time out before the first try to connect to the failover partner server when you try to connect to a SQL Server 2005 mirrored database by using an ADO.NET 2.0-based application
(http://support.microsoft.com/kb/912731/ )FIX: When an ADO.NET-connected application uses the System.Data.SqlClient namespace, the application may experience high CPU use and may stop responding
(http://support.microsoft.com/kb/912732/ )FIX: An error may occur when you start a new transaction in ADO.NET 2.0 on a connection that is open to a SQL Server 2005 database
(http://support.microsoft.com/kb/913177/ )FIX: You may receive an error message when an ADO.NET-connected application uses the SqlBulkCopy class
(http://support.microsoft.com/kb/913764/ )FIX: Error message when you try to run a UNION ALL query or to call the DeriveParameters method: "Internal connection fatal error"
(http://support.microsoft.com/kb/913765/ )FIX: An SqlException exception may occur when you call one of the Execute methods on the instance of the SqlCommand class in an ADO.NET 2.0 application
(http://support.microsoft.com/kb/913766/ )FIX: A DateTime column that does not contain any data is incorrectly represented by a DateTime.MinValue field when a .NET Framework 2.0 DataSet object is deserialized on a client computer