I'm running an ASP.NET Web Pages page that upon initial load pulls a list of items from a SQL server. This query runs in a second or so and loads the page within 2 seconds. The return is about a 1000 records, give or take. I'm pulling Hostnames from a Service Manager SQL database along with some other information.

Within this page, I have a search built in that essentially runs the exact same query but runs it with a LIKE based on hostname. This loads the same page with all hostnames that are contain part of the search query. The query generally runs within SQL Management Studio in under a second, but loading the page takes substantially longer and sometimes it times out.

My question is, why does the parameter based search takes so much longer and sometimes timeout for no apparent reason. Are there any steps that can be taken to mitigate this timeout? Below is the full error.

Server Error in '/' Application.

The wait operation timed out 

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details:

System.ComponentModel.Win32Exception: The wait operation timed out
Source Error: 

Line 13:     }
Line 14:     
Line 15:     var selectedData = db.Query(selectCommand, searchTerm);
Line 16: 
Line 17:

Source File:  c:\Users\u0149920\Documents\My Web Sites\AppSupport\servers\default.cshtml    Line:  15

Stack Trace:

[Win32Exception (0x80004005): The wait operation timed out]
[SqlException (0x80131904): Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +1753346
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +5295154
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +242
   System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +1682
   System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() +59
   System.Data.SqlClient.SqlDataReader.get_MetaData() +90
   System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +365
   System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite) +1325
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) +175
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +53
   System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +134
   System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +41
   System.Data.Common.DbCommand.ExecuteReader() +12
   WebMatrix.Data.<QueryInternal>d__0.MoveNext() +152
   System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +381
   System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
   WebMatrix.Data.Database.Query(String commandText, Object[] parameters) +103
   ASP._Page_servers_default_cshtml.Execute() in c:\Users\u0149920\Documents\My Web Sites\AppSupport\servers\default.cshtml:15
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +197
   System.Web.WebPages.WebPage.ExecutePageHierarchy(IEnumerable`1 executors) +69
   System.Web.WebPages.WebPage.ExecutePageHierarchy() +151
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +76
   System.Web.WebPages.WebPageHttpHandler.ProcessRequestInternal(HttpContextBase httpContext) +114

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.17929

The problem you are having is the query command is taking too long. I believe that the default timeout for a query to execute is 15 seconds. You need to set the CommandTimeout (in seconds) so that it is long enough for the command to complete its execution. The "CommandTimeout" is different than the "Connection Timeout" in your connection string and must be set for each command.

In your sql Selecting Event, use the command:

e.Command.CommandTimeout = 60

for example:

Protected Sub SqlDataSource1_Selecting(sender As Object, e As System.Web.UI.WebControls.SqlDataSourceSelectingEventArgs)
    e.Command.CommandTimeout = 60
End Sub