Hi Handy,

No. I can NOT predict when it will happen the next time.

I also can NOT set breakpoints nor debug on that server. But I can add additional logging into text files or the database if required. Let me know what exactly you want to get logged.

Eric

Hi Handy,

No, this does not happen on specific times. So we cannot predict when it will happen the next time.

I have no access to this production server and will not get access - much less someone from outside our company. If you need to debug, then maybe you can tell me what to monitor and I can request this monitoring or add debug output or something similar.

Let me know what you need to look at.

Regards, Eric

Hi Handy,

Has this been fixed (in WebGrid 7) in the meantime? I didn't see a thread update.

Thanks,
Eric

Hi Handy,

I don't understand what you need here. I don't have any additional information available. I have no access to the server (but could request something) and at the time it happened I could log all HTTP communication to the server. For the mentioned crash, I can see that after the WebGrid request to the server goes out, an error page with status 500 gets sent back. The WebGrid detects this answer as illegal answer from the server and runs an OnUnhandledError event, so that the client gets redirected to a general error page. The user only sees this general error page. From the HTTP log I could extract the original error message with the status 500 and the stack trace. The error message itself was also listed in my post, so there's no other information available.

If you need anything else, please let me know how I should obtain this information.

Maybe you meant that you want a screenshot of the usual unhandled error dialogs. But as mentioned earlier, we don't have these dialogs anymore, because we catch unhandled errors in our code and redirect to a custom (general) error page if this happens.

Thanks,

Eric

Currently it's crashing about once a week, like today again. What I saw is that on another page it crashes when loading data on demand (opening a node in a grid). This is somewhat different from the other crashes, as there is a server-side crash involved, not only no data being responded to the client. But as this is probably the same internal problem, maybe it helps you find the cause. Here are the details.

Protected Sub grdMain_InitializeSelfReferenceDataSource(ByVal sender As Object, ByVal e As ISNet.WebUI.WebGrid.ChildTableDataSourceEventArgs) Handles grdMain.InitializeSelfReferenceDataSource
	Dim ds As DataSet = Nothing
	Dim MainGridId As String = e.ParentKeyValues("Unique_ID").ToString()

	If MainGridId.StartsWith("F_") Then
		ds = GetData(GetNumFromMainGridId(MainGridId))
	End If

	Dim dt As DataTable = CType(e.DataSource, DataTable)
	If Not IsNothing(ds) AndAlso Not IsNothing(ds.Tables(0)) AndAlso ds.Tables(0).Rows.Count > 0 Then
		dt.Merge(ds.Tables(0), True, MissingSchemaAction.Error)
	End If
End Sub

This crashes somehow. The full error message is not being displayed, because the client redirects to an error page. But tracing the HTTP traffic I can see the error message. The error message is the usual yellow ASP.NET error message and it says: Target table Table missing definition for column Location.

Stack trace says:

[DataException: Target table Table missing definition for column Location.]
   System.Data.Merger.MergeSchema(DataTable table) +632
   System.Data.Merger.MergeTableData(DataTable src) +31
   System.Data.Merger.MergeTable(DataTable src) +187
   System.Data.DataTable.Merge(DataTable table, Boolean preserveChanges, MissingSchemaAction missingSchemaAction) +128
   Modules_MainPage.grdMain_InitializeSelfReferenceDataSource(Object sender, ChildTableDataSourceEventArgs e) +251
   ISNet.WebUI.WebGrid.WebGrid.OnInitializeSelfReferenceDataSource(WebGridTable table, Object dataSource, String parentConstraints, String customReqData) +720
   ISNet.WebUI.WebGrid.DataBinding.???(WebGridTable table, DataView view) +210
   ISNet.WebUI.WebGrid.DataBinding.????(WebGrid grid, WebGridTable table, DataView dataSource) +4633
   ISNet.WebUI.WebGrid.DataBinding.??(DataView dataSource, String dataMember, String request) +562
   ISNet.WebUI.WebGrid.DataBinding.DataBind(Object dataSource, String dataMember) +674
   ISNet.WebUI.WebGrid.WebGrid.??() +44
   ISNet.WebUI.ISNetControl.ControlRequestHandler(Object sender, EventArgs e) +293

[Exception: Target table Table missing definition for column Location.]
   ISNet.WebUI.ISNetControl.ControlRequestHandler(Object sender, EventArgs e) +446
   System.EventHandler.Invoke(Object sender, EventArgs e) +0
   System.Web.UI.Control.OnPreRender(EventArgs e) +2069340
   System.Web.UI.Control.PreRenderRecursiveInternal() +77
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1360

What I read out of this is this: My code correctly gets the data from the database and tries to merge it into the existing WebGrid data. This fails, because the grid doesn't provide the correct column definition anymore. e.DataSource is probably empty or something like that. I assume because of another problem that happened within WebGrid somehow.

Maybe this additional info helps in some way.

Eric