Asp.Net Random Error

Question

At random times, twice in the past two weeks, the we application will start to error and not work until I recycle the app pool in IIS.

The specific error and stacktrace are:

System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.InvalidCastException: Unable to cast object of type 'System.Guid' to type 'System.String'.
   at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult)
   at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries)
   at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query)
   at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute[S](Expression expression)
   at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source)
   at DigitalScout.WEDS.Business.Slug.GetTeamPath(String teamID)
   at DigitalScout.WEDS.WebApp.Code.Navigator.TeamNavigator.Home(String teamID)
   at ASP.management_default_aspx.__DataBind__control7(Object sender, EventArgs e)
   at System.Web.UI.Control.OnDataBinding(EventArgs e)
   at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
   at System.Web.UI.Control.DataBindChildren()
   at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
   at System.Web.UI.WebControls.Repeater.CreateControlHierarchy(Boolean useDataSource)
   at System.Web.UI.WebControls.Repeater.OnDataBinding(EventArgs e)
   at System.Web.UI.Control.DataBindChildren()
   at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
   at System.Web.UI.WebControls.Repeater.CreateControlHierarchy(Boolean useDataSource)
   at System.Web.UI.WebControls.Repeater.OnDataBinding(EventArgs e)
   at DigitalScout.WEDS.WebApp.Management._default.Page_Load(Object sender, EventArgs e)
   at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at DigitalScout.WEDS.WebApp.Code.BaseClass.Pages.ManagementPage.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   --- End of inner exception stack trace ---
   at System.Web.UI.Page.HandleError(Exception e)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at ASP.management_default_aspx.ProcessRequest(HttpContext context)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

This error happens for every user of the system until the app pool is recycled. Any help on this would be helpful as we are not able to reproduce the error.

@Mitch Wheat, yes, that's the actual Error being thrown, but it's being thrown from inside the SqlClient code that Linq2Sql uses, not the code we've written. Also, this code works most of the time - until this error crops up every so often making it necessary to recycle the app pool. — John Boker, Mar 17 '10 at 15:59
@Mitch Wheat, I'm going to look into your answer, thank you for your help on this :) — John Boker, Mar 17 '10 at 16:02

score 1 · Accepted Answer · edited May 23 '17 at 11:47

1

Apparently, the problem goes away if you Dispose your DataContexts:

edited May 23 '17 at 11:47

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answered Mar 17 '10 at 15:58

Mitch Wheat

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Our datacontext implements the IDisposable interface, is this not enough to have the object disposed of when going out of scope? The Dispose method closes the connection if one is open and calls the base Dispose method. – John Boker Mar 17 '10 at 17:07
You should be explicitly calling Dispose. – Mitch Wheat Mar 18 '10 at 01:07
Thanks, that was what i was afraid of. – John Boker Mar 18 '10 at 05:02
Or better use the "using" block. – Ashish Gupta Mar 21 '10 at 10:28

Asp.Net Random Error

1 Answers1