Compare the set options by collecting an Extended Events trace (login and connecting events with collect_options_text) and check the options_text column. If the queries are fast in SQLCMD and SSMS, but slow on the application side, change the queries to use the same set options used in SQLCMD and SSMS. In SQLCMD and SSMS, the time-out value is set to 0 (no time limit) and the queries can be tested and investigated. If you observe a completed event is immediately followed by an attention event, and the duration of the completed event corresponds approximately to the time-out setting, you have identified the query. You can trace the attention event together with the sql_batch_completed and rpc_completed extended events, and correlate them on the same session_id. Use Extended Events or SQL Trace to identify the queries that cause the time-out errors. This should be the first target of your troubleshooting. Troubleshooting stepsД«y far, the most common reason for query time-outs is underperforming queries. For more information, see Query time-out is not the same as connection time-out. The latter controls how long to wait for a successful connection and isn't involved in query execution. Query time-out is different from a connection time-out property. In VBA (Excel), it's set through the property.In OLEDB, it's set through the DBPROP_COMMANDTIMEOUT property on the DBPROP structure.In Java Database Connectivity (JDBC) API, it's set through the setQueryTimeout method.In ODBC API, it's set through the SQL_ATTR_QUERY_TIMEOUT attribute in the SQLSetStmtAttr function.NET Framework, the time-out value is set on the CommandTimeout property. If the time-out value is set to 0 (no time limit), the Database Engine will execute the query until it's completed. On the SQL Server side, a query cancellation causes an Attention event, error 3617 ( MSSQLSERVER_3617). The application sets a time out value and if the time out is reached, it cancels the query.

These errors occur on the application side. The timeout period elapsed prior to completion of the operation or the server is not responding. If the query doesn't return any data within the configured time-out value (typically 30 seconds), the application cancels the query and generates one of these error messages: Assume that an application queries data from a SQL Server database.

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