Microsoft KB Archive/152062

= FIX: Query Times Out Too Early Under Multiprotocol Net- Library =

Article ID: 152062

Article Last Modified on 3/14/2006

-

APPLIES TO


 * Microsoft SQL Server 6.0 Standard Edition
 * Microsoft SQL Server 6.5 Standard Edition

-



This article was previously published under Q152062



BUG #: 15252 (SQLBUG_60_RW and SQLBUG_65)



SYMPTOMS
When you use DBMSRPC3.DLL to connect to SQL Server, a Win16 application can prematurely time out the query. For example, if the query timeout is set to 55 seconds using dbsettime in a DB-Library application, the query will timeout within 10 seconds. With settings under 30 seconds, the query timeout setting works fine.



CAUSE
The timeout mechanism in ConnectionRead of the client-side Net-Library DBMSRPC3.DLL incorrectly calculates the timeout setting under certain situations.



WORKAROUND
Use either of the following to work around the problem:


 * Use non-blocking calls to execute queries. For example, in DBLIB, instead of calling dbsqlexec, you can call dbsqlsend to send the query first, and then call dbdataready repeatedly until it returns true, and finally call dbsqlok. You'll need to implement your own timeout mechanism to break out of the dbdataready loop. For ODBC applications, you can avoid this by using asynchronous mode. For more information, please consult the Programmer's Reference for C. -OR-


 * Set the timeout value to less than 30 seconds, and use a counter to control the accumulated timeout value until it is equal to the ideal setting. For instance, in DBLIB, use dbsettime to set a value less than 30 seconds, and code your error handler to always return INT_CONTINUE on the timeout error until the total amount of time waited is equal to your ideal setting. As an example, if you want to set the query timeout to 120, you can set the initial timeout value to 30 seconds, and have the error handler return INT_CONTINUE until the timeout error occurs consecutively for four times.



STATUS
Microsoft has confirmed this to be a problem in Microsoft SQL Server version 6.0.

Microsoft has confirmed this to be a problem in SQL Server 6.5. This problem has been corrected in Service Pack 5a for Microsoft SQL Server 6.5.For more information, click the following article number to view the article in the Microsoft Knowledge Base:

197177 INF: How to Obtain SQL Server 6.5 Service Pack 5a

For more information, contact your primary support provider.



MORE INFORMATION
This is a Net-Library specific issue. It occurs when the application API (DBLIB or ODBC) calls the Net-Library API function ConnectionRead to read results from the server. The timeout value parameter is correctly passed to ConnectionRead, but the function does not wait long enough before timing out. This problem can affect both DBLIB and ODBC applications.

Keywords: kbbug kbfix KB152062

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.