Internal Connection Fatal Error

[SteveoAtilla]

Hello!

 

I wasn't sure if this should go into the ASP.NET forum, or the Database forum, so I'll cross-post in both.

 

Anyway, I have just started getting this error (trapped by a try...catch...end try structure) in an app that has been functioning well for over 18 months.

 

I am getting this in my development environment (Windows XP machine with a Windows Server 2003 SQL virtual machine), and since I am trapping the error, I don't get the full stack trace. Anyway, I don't believe that there is a single set of commands that trigger the error, since I can comment out one of the subs with DB access, and I still get the error.

 

Just for reference, here is one of the DB routines anyway:

 

Dim ProductionBOMCmdText As String
Dim ProductionBOMCommand As New SqlCommand

ProductionBOMCmdText = "UPDATE dbo.ProductionBOM SET WorkcenterNumber = 40600425 WHERE (SerialNumberProfile <> '') AND (WorkcenterNumber = '') AND (MachineMasterPK = ViewState("MachineMasterPK") & ")"

ConnectionAlpha.ConnectionString = ViewState("ConnectionString")
ConnectionAlpha.Open()
Try
   ProductionBOMCommand = New SqlCommand(ProductionBOMCmdText, ConnectionAlpha)
   Dim ra As Integer = ProductionBOMCommand.ExecuteNonQuery()
Catch ex As Exception
  DisplayAlert("UNEXPECTED ERROR!\nPage: InitiateMachine.aspx\nSubroutine: FixTheBOM\nLine: 2376\nError Message: " & Replace(ex.Message, vbCrLf, "\n") & "\nCommand Text:\n" & ProductionBOMCmdText)
End Try
ConnectionAlpha.Close()

I tried to change all the SQL Connections, have re-booted the SQL server, and went ahead and did the KB fix for .NET 2.0, even though this app uses 1.4.

 

What's going on? The rest of the application works fine. It's just this one page that is now throwing errors. Unfortunately, this is kind of the core of the app, and does literally hundreds of SQL transactions every time it is used.

 

What might be going on? I didn't change all that much...

 

Thanks,

 

Steveo

[PlausiblyDamp]

When you catch the error could you also log ex.ToString() as that would give yu more information regarding the stack trace.

 

Are you closing all you connections properly in your application? Try ... Finally blocks could help here; you might want to check through the SQL admin tool or perfmon how many active connections there are - if there are a large number then this error can occur as the server is possibly running at it's limit.

 

Also - just as an aside : are you really storing the connection string and SQL criteria in the viewstate?

[SteveoAtilla]

Hey, thanks for the quick reply.

 

To try to get more info, I turned the Catch off and found out where the error is actually triggering.

 

Here is that code:

 

Private Sub CreateResponsesEntries()
' Procedure to copy ALL of the Checklist Questions for the Initiated Production Order into the 
'  Responses table.
Dim ChecklistCmdText As String
Dim ChecklistCommand As New SqlCommand
Dim QuestionCmdText As String
Dim QuestionCommand As New SqlCommand
Dim ResponseCmdText As String
Dim ResponseCommand As New SqlCommand
Dim SecBreak As Integer
Dim RespOpt As Integer
Dim QuesText As String
Dim ChecklistPK As Integer
Dim Resp1Optional As Integer
Dim Resp2Optional As Integer

' Query to get ALL the Checklist Master Primary Keys for all the Checklists in the Checklsit Status
'  table for this Machine Master
ChecklistCmdText = "SELECT ChecklistMasterPK FROM dbo.ChecklistStatus WHERE MachineMasterPK = " & ViewState("MachineMasterPK")

ConnectionZeta.ConnectionString = ViewState("ConnectionString")
ConnectionZeta.Open()
ChecklistCommand = New SqlCommand(ChecklistCmdText, ConnectionZeta)
Dim ChecklistData As SqlDataReader = ChecklistCommand.ExecuteReader(CommandBehavior.CloseConnection)

If ChecklistData.HasRows Then   ' For each Checklist found for this Production Order, all Questions
   While ChecklistData.Read    '  must be found and copied to the Responses table.
   ChecklistPK = ChecklistData.GetValue(0)

   QuestionCmdText = "SELECT ChecklistDetail.QuestionsPK, ChecklistDetail.ResponseType1, ChecklistDetail.ResponseType2, ChecklistDetail.ResponseList1, ChecklistDetail.ResponseList2, ChecklistDetail.LabelText, ChecklistDetail.ChecklistPK, ChecklistDetail.Image,  ChecklistDetail.SortOrder, ChecklistDetail.LabelNumber, ChecklistDetail.SectionBreak, ChecklistDetail.QuestionRevNum, ChecklistDetail.QuestionRevDate, ChecklistDetail.QuestionCreateDate, ChecklistDetail.QuestionRevisedDate, ChecklistDetail.ResponseOptional, BinderDetail.WorkcenterPK, ChecklistDetail.AddlResp1Optional, ChecklistDetail.AddlResp2Optional FROM ChecklistDetail INNER JOIN BinderDetail ON ChecklistDetail.ChecklistPK = BinderDetail.ChecklistPK WHERE (ChecklistDetail.ChecklistPK = " & ChecklistPK & ") ORDER BY ChecklistDetail.SortOrder"

   ConnectionTheta.ConnectionString = ViewState("ConnectionString")
   ConnectionTheta.Open()
   QuestionCommand = New SqlCommand(QuestionCmdText, ConnectionTheta)
   Dim QuestionData As SqlDataReader = QuestionCommand.ExecuteReader(CommandBehavior.Default)

   If QuestionData.HasRows Then    ' If there are any Questions for this Checklist...
       While QuestionData.Read
           QuesText = Replace(Replace(QuestionData.GetValue(5), """", "``"), "'", "`")
           If IsDBNull(QuestionData.GetValue(10)) Then
               SecBreak = 0
           ElseIf QuestionData.GetValue(10) = True Then
               SecBreak = 1
           Else
               SecBreak = 0
           End If
           If IsDBNull(QuestionData.GetValue(15)) Then
               RespOpt = 0
           ElseIf QuestionData.GetValue(15) = True Then
               RespOpt = 1
           Else
               RespOpt = 0
           End If
           If IsDBNull(QuestionData.GetValue(17)) Then
               Resp1Optional = 1
           ElseIf QuestionData.GetValue(17) Then
               Resp1Optional = 1
           Else
               Resp1Optional = 0
           End If
           If IsDBNull(QuestionData.GetValue(18)) Then
               Resp2Optional = 1
           ElseIf QuestionData.GetValue(18) Then
               Resp2Optional = 1
           Else
               Resp2Optional = 0
           End If
           ' Query to Insert all the Details for this Question into the Responses table...
            ResponseCmdText = "INSERT INTO dbo.Responses (ProductionOrderPK, WorkCenterPK, QuestionPK, ResponseCheck, ResponseType1, ResponseType2, ResponseList1, ResponseList2, LabelText, ChecklistPK, Image, SortOrder, LabelNumber, SectionBreak, QuestionRevNum, QuestionRevDate, QuestionCreateDate, QuestionRevisedDate, ResponseOptional, AddlResp1Optional, AddlResp2Optional) VALUES (" & ViewState("MachineMasterPK") & ", '" &  QuestionData.GetValue(16) & "', '" & QuestionData.GetValue(0) & "', '" & "-1', '" & QuestionData.GetValue(1) & "', '" & QuestionData.GetValue(2) & "', '" & QuestionData.GetValue(3) & "', '" & QuestionData.GetValue(4) & "', '" &  QuesText & "', " & QuestionData.GetValue(6) & ", '" & QuestionData.GetValue(7) & "', '" & QuestionData.GetValue(8) & "', '" & QuestionData.GetValue(9) & "', '" & SecBreak & "', '" & QuestionData.GetValue(11) & "', '" & QuestionData.GetValue(12) & "', '" & QuestionData.GetValue(13) & "', '" & QuestionData.GetValue(14) & "', '" & RespOpt & "', '" & Resp1Optional & "', '" & Resp2Optional & "')"

            ConnectionGamma.ConnectionString = ViewState("ConnectionString")
            ConnectionGamma.Open()
            Try
                ResponseCommand = New SqlCommand(ResponseCmdText, ConnectionGamma)
                Dim ra As Integer = ResponseCommand.ExecuteNonQuery()
            Catch ex As Exception
                DisplayAlert("UNEXPECTED ERROR!\nPage: InitiateMachine.aspx\nSubroutine: CreateResponsesEntries\nLine: 2046\nError Message: " & Replace(ex.Message, vbCrLf, "\n") & "\nCommand Text:\n" & ResponseCmdText)
            End Try
            ConnectionGamma.Close()
        End While
    End If

    QuestionData.Close()
    ConnectionTheta.Close()

    CreateHeaderQuestions(ChecklistPK)      ' Call the Procedure to get the Checklist Header
End While                                   '  Questions for this Checklist
End If

ChecklistData.Close()
ConnectionZeta.Close()
   End Sub

And here's the error stack trace:

Internal connection fatal error. 
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.InvalidOperationException: Internal connection fatal error.

Source Error: 


Line 2057:                End If
Line 2058:
Line 2059:                QuestionData.Close()
Line 2060:                ConnectionTheta.Close()
Line 2061:


Source File: c:\inetpub\wwwroot\PMTravelBinder\InitiateMachine.aspx.vb    Line: 2059 

Stack Trace: 


[invalidOperationException: Internal connection fatal error.]
  System.Data.SqlClient.SqlDataReader.InternalClose(Boolean closeReader)
  System.Data.SqlClient.SqlDataReader.Close()
  PMTravelBinder.InitiateMachine.CreateResponsesEntries() in c:\inetpub\wwwroot\PMTravelBinder\InitiateMachine.aspx.vb:2059
  PMTravelBinder.InitiateMachine.btnPost_Click(Object sender, EventArgs e) in c:\inetpub\wwwroot\PMTravelBinder\InitiateMachine.aspx.vb:1576
  System.Web.UI.WebControls.Button.OnClick(EventArgs e)
  System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
  System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
  System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
  System.Web.UI.Page.ProcessRequestMain()

Does this shed any additional light?

 

Thanks!

 

Steveo

[SteveoAtilla]

Damp,

 

Yeah, I'm really storing the SQL connection string in a ViewState. It's strictly an internal app with no exposure to the outside.

 

Steveo

[PlausiblyDamp]

Looks like it is a problem inside their code rather than yours - did you check to see if you were leaving connections open?

[SteveoAtilla]

I've checked all the code for unclosed connections, but will do so again.

 

Whose code is "their" code? Can't figure out your reference....

 

 

Steveo

[PlausiblyDamp]

The error appears to be being thrown by Microsoft's code - it is an error inside the SQlDataReader class itself - this is either a problem with the DataReader or with the connection to SQL itself.

 

As well as checking you are closing all connections you really should monitor it with a 3rd party tool - this will show what is actually happening rather than what the code suggests is happening. There is always the possibility that readers / connections are not being closed if errors occur as your close statements are outside of the try block.