Verbesserung der Stabilität und Fehlerbehandlung

- `MSSQLServer.vb`: Konvertierung von `Nothing`-Werten zu `DBNull.Value` und detaillierte Protokollierung von SQL-Fehlern hinzugefügt. - `AssemblyInfo.vb`: Aktualisierung der Assembly-Version auf `2.4.0.0`. - `Client.vb`: Einführung von `_IsReconnecting`, um parallele Reconnects zu verhindern. Verbesserte Fehlerbehandlung, Protokollierung und Ressourcenfreigabe. - `MailSession.vb`: Konsistentere Protokollierung, Änderung von `Info` zu `Debug` beim Schließen der Verbindung. - `EDMI.API.vbproj`: Hinzufügen der Datei `ErrorLog.txt`. - `ErrorLog.txt`: Dokumentation von Timeout- und Verbindungsproblemen mit detaillierten Stack-Traces. Diese Änderungen verbessern die Stabilität, Fehlertoleranz und Protokollierungsqualität der Anwendung.
2026-09-29 15:49:15 +02:00
parent 298a398067
commit de918b1e88
6 changed files with 439 additions and 51 deletions
--- a/EDMIAPI/Client.vb
+++ b/EDMIAPI/Client.vb
@@ -1,5 +1,6 @@
 Imports System.IO
 Imports System.ServiceModel
+Imports System.Threading
 Imports DigitalData.Modules.Base
 Imports DigitalData.Modules.EDMI.API.Constants
 Imports DigitalData.Modules.EDMI.API.EDMIServiceReference
@@ -23,6 +24,8 @@ Public Class Client
    Private _ClientConfig As GlobalStateClientConfiguration
    Private _CachedTables As New List(Of String)
    Private _IsOnline As Boolean
+    ' Verhindert parallele Reconnect-Versuche (0 = frei, 1 = läuft)
+    Private _IsReconnecting As Integer = 0
    Private _Channel As IEDMIServiceChannel
    Private _ClientName As String
    ' Static Registry
@@ -52,23 +55,26 @@ Public Class Client
    End Sub
    Protected Overridable Sub Dispose(disposing As Boolean)
        If _Disposed Then Return
-
        If disposing Then
+            _IsOnline = False          ' ← Reconnect-Guard deaktivieren
            UpdateTimer.Stop()
            UpdateTimer.Dispose()

+            ' Auf laufenden Reconnect warten
+            Dim oTimeout = DateTime.Now.AddSeconds(5)
+            While _IsReconnecting = 1 AndAlso DateTime.Now < oTimeout
+                Task.Delay(100).Wait()
+            End While
+
            If _Channel IsNot Nothing Then
                Channel.CloseChannel(_Channel)
                _Channel = Nothing
            End If

-            ' Aus Registry austragen
            Dim oRemoved As ClientStatus = Nothing
            _ActiveClients.TryRemove(_ClientId, oRemoved)
            Logger.Debug("Client [{0}] unregistered. Total active clients: [{1}]", _ClientName, _ActiveClients.Count)
-            Logger.Debug("Client disposed. Channel closed.")
        End If
-
        _Disposed = True
    End Sub

@@ -125,7 +131,7 @@ Public Class Client
        _ClientId = $"{_ClientName}_{Guid.NewGuid().ToString("N").Substring(0, 8)}"  ' ← eindeutig

        UpdateTimer.Interval = 60 * 1000 * UPDATE_INTERVAL_IN_MINUTES
-        UpdateTimer.Start()
+        ' Start erfolgt in Connect()

        Try
            Dim oConnection = New Connection()
@@ -154,7 +160,6 @@ Public Class Client
        _ClientId = $"{_ClientName}_{Guid.NewGuid().ToString("N").Substring(0, 8)}"  ' ← eindeutig

        UpdateTimer.Interval = 60 * 1000 * UPDATE_INTERVAL_IN_MINUTES
-        UpdateTimer.Start()

        Try
            Dim oConnection = New Connection()
@@ -188,7 +193,6 @@ Public Class Client

            Logger.Info("✔✔Connection to AppService [{0}] successfully established! | Client=[{1}] | Id=[{2}]",
                        ServerAddress, _ClientName, _ClientId)
-            _IsOnline = True

            ' CachedTables sofort befüllen – nicht auf den ersten Timer-Tick warten
            Try
@@ -199,14 +203,17 @@ Public Class Client
                Logger.Warn("⚠ CachedTables could not be loaded on connect: {0}", ex.Message)
                _CachedTables = New List(Of String)
            End Try
-            ' In Registry eintragen
+
+            _IsOnline = True              ' ← vor GetStatus()
+            UpdateTimer.Start()
+
+            ' In Registry eintragen – jetzt mit korrektem IsOnline=True
            _ActiveClients(_ClientId) = GetStatus()
            Logger.Info("Client [{0}] registered with Id=[{1}]. Total active clients: [{2}]", _ClientName, _ClientId, _ActiveClients.Count)

            Return True
        Catch ex As Exception
            _IsOnline = False
-
            Logger.Error(ex)
            Return False
        End Try
@@ -215,30 +222,46 @@ Public Class Client
    ''' <summary>
    ''' Aborts the channel and creates a new connection
    ''' </summary>
-    Public Async Sub Reconnect()
-        Logger.Warn("⚠ Connection faulted. Trying to reconnect..")
+    Public Async Sub Reconnect(Optional sender As Object = Nothing, Optional e As EventArgs = Nothing)
+        ' Nur ein Reconnect gleichzeitig erlauben – atomar prüfen und setzen
+        If Interlocked.CompareExchange(_IsReconnecting, 1, 0) = 1 Then
+            Logger.Debug("Reconnect already in progress – skipping duplicate call.")
+            Return
+        End If

-        Dim oRetryDelays = {2, 5, 15, 30}
+        Try
+            Logger.Warn("⚠ Connection faulted. Trying to reconnect..")

-        For Each oDelay In oRetryDelays
-            Try
-                Await Task.Delay(TimeSpan.FromSeconds(oDelay))
-                Logger.Debug($"Reconnect attempt after {oDelay}s delay...")
+            Dim oRetryDelays = {2, 5, 15, 30}

-                Channel.CloseChannel(_Channel)  ' Sauber schließen statt Abort
-                _Channel = ChannelManager.GetChannel()
-                _Channel.Open()
+            For Each oDelay In oRetryDelays
+                Try
+                    Await Task.Delay(TimeSpan.FromSeconds(oDelay))
+                    Logger.Debug("Reconnect attempt after [{0}]s delay...", oDelay)

-                _IsOnline = True
-                Logger.Info("Reconnect successful.")
-                Return
-            Catch ex As Exception
-                Logger.Warn($"⚠ Reconnect failed: {ex.Message}")
-                _IsOnline = False
-            End Try
-        Next
+                    Channel.CloseChannel(_Channel)
+                    _Channel = ChannelManager.GetChannel()
+                    _Channel.Open()

-        Logger.Error("All reconnect attempts failed. Service unavailable.")
+                    _IsOnline = True
+
+                    If _ActiveClients.ContainsKey(_ClientId) Then
+                        _ActiveClients(_ClientId) = GetStatus()
+                    End If
+
+                    Logger.Info("✔ Reconnect successful.")
+                    Return
+                Catch ex As Exception
+                    Logger.Warn("⚠ Reconnect failed after [{0}]s: {1}", oDelay, ex.Message)
+                    _IsOnline = False
+                End Try
+            Next
+
+            Logger.Error("All reconnect attempts failed. Service unavailable.")
+        Finally
+            ' Flag immer zurücksetzen – auch bei unerwarteten Fehlern
+            Interlocked.Exchange(_IsReconnecting, 0)
+        End Try
    End Sub

    Private Async Sub UpdateTimer_Elapsed(sender As Object, e As Timers.ElapsedEventArgs) Handles UpdateTimer.Elapsed
@@ -246,7 +269,7 @@ Public Class Client
            If _Channel Is Nothing OrElse _Channel.State <> CommunicationState.Opened Then
                Logger.Warn("⚠ UpdateTimer skipped: Channel not in Opened state [{0}]", If(_Channel IsNot Nothing, _Channel.State.ToString(), "null"))
                _IsOnline = False
-                Reconnect()
+                Reconnect(sender, e)
                Return
            End If

@@ -825,10 +848,8 @@ Public Class Client
            })
        Catch ex As EndpointNotFoundException
            HandleCommunicationError(ex, NameOf(ExecuteNonQueryFromIDB))
-            Throw
        Catch ex As CommunicationException
            HandleCommunicationError(ex, NameOf(ExecuteNonQueryFromIDB))
-            Throw
        Catch ex As Exception
            Logger.Error(ex)
            Throw
@@ -974,15 +995,15 @@ Public Class Client

        Catch ex As FaultException(Of ObjectDoesNotExistFault)
            Logger.Error(ex)
-            Throw ex
+            Throw

        Catch ex As FaultException
            Logger.Error(ex)
-            Throw ex
+            Throw

        Catch ex As Exception
            Logger.Error(ex)
-            Throw ex
+            Throw

        End Try
    End Function
@@ -1001,7 +1022,7 @@ Public Class Client
            }
        Catch ex As Exception
            Logger.Error(ex)
-            Throw ex
+            Throw
        End Try
    End Function
    ''' <summary>
@@ -1035,12 +1056,27 @@ Public Class Client
            Throw New InvalidOperationException("Channel is not initialized. Call Connect() first.")
        End If

-        If _Channel.State <> CommunicationState.Opened Then
-            Throw New InvalidOperationException($"Channel is not available. State=[{_Channel.State}]")
+        If Not _IsOnline Then
+            ' Kurze Grace-Period abwarten, damit Reconnect() seinen _IsReconnecting-Flag setzen kann
+            Dim oGraceLimit = DateTime.Now.AddMilliseconds(600)
+            While DateTime.Now < oGraceLimit AndAlso _IsReconnecting = 0 AndAlso Not _IsOnline
+                Task.Delay(100).Wait()
+            End While
+
+            ' Jetzt auf aktiven Reconnect warten
+            Dim oWaitLimit = DateTime.Now.AddSeconds(10)
+            While Not _IsOnline AndAlso DateTime.Now < oWaitLimit AndAlso _IsReconnecting = 1
+                Task.Delay(500).Wait()
+                Logger.Debug("EnsureAvailable: Waiting for reconnect... Channel=[{0}]", _Channel.State.ToString())
+            End While
+
+            If Not _IsOnline Then
+                Throw New InvalidOperationException("Client is offline.")
+            End If
        End If

-        If Not _IsOnline Then
-            Throw New InvalidOperationException("Client is offline.")
+        If _Channel.State <> CommunicationState.Opened Then
+            Throw New InvalidOperationException($"Channel is not available. State=[{_Channel.State}]")
        End If
    End Sub
    ''' <summary>
@@ -1049,11 +1085,11 @@ Public Class Client
    Private Sub HandleCommunicationError(ex As Exception, callerName As String)
        Select Case True
            Case TypeOf ex Is EndpointNotFoundException
-                Logger.Warn("⚠ Service not reachable (EndpointNotFoundException in {0}). Triggering reconnect...", callerName)
+                Logger.Warn("⚠ Service not reachable (EndpointNotFoundException in [{0}]). Triggering reconnect...", callerName)
            Case TypeOf ex Is CommunicationException
-                Logger.Warn("⚠ in {0} during call. Triggering reconnect...", callerName)
+                Logger.Warn("⚠ CommunicationException in [{0}] during call. Triggering reconnect...", callerName)
            Case Else
-                Logger.Warn("⚠ Unexpected exception in {0} during call. Triggering reconnect...", callerName)
+                Logger.Warn("⚠ Unexpected exception in [{0}] during call. Triggering reconnect...", callerName)
                Logger.Error(ex)
        End Select