EventLog.OverflowAction Property

Definition

Namespace:

System.Diagnostics

Assembly:

System.Diagnostics.EventLog.dll

Gets the configured behavior for storing new entries when the event log reaches its maximum log file size.

public:
 property System::Diagnostics::OverflowAction OverflowAction { System::Diagnostics::OverflowAction get(); };

[System.ComponentModel.Browsable(false)]
public System.Diagnostics.OverflowAction OverflowAction { get; }

[<System.ComponentModel.Browsable(false)>]
member this.OverflowAction : System.Diagnostics.OverflowAction

Public ReadOnly Property OverflowAction As OverflowAction

Property Value

OverflowAction

The OverflowAction value that specifies the configured behavior for storing new entries when the event log reaches its maximum log size. The default is OverwriteOlder.

Attributes

BrowsableAttribute

Examples

The following example enumerates the event logs defined on the local computer, and displays configuration details for each event log.

void DisplayEventLogProperties()
{
   
   // Iterate through the current set of event log files,
   // displaying the property settings for each file.
   array<EventLog^>^eventLogs = EventLog::GetEventLogs();
   System::Collections::IEnumerator^ myEnum = eventLogs->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      EventLog^ e = safe_cast<EventLog^>(myEnum->Current);
      Int64 sizeKB = 0;
      Console::WriteLine();
      Console::WriteLine( "{0}:", e->LogDisplayName );
      Console::WriteLine( "  Log name = \t\t {0}", e->Log );
      Console::WriteLine( "  Number of event log entries = {0}", e->Entries->Count );
      
      // Determine if there is a file for this event log.
      RegistryKey ^ regEventLog = Registry::LocalMachine->OpenSubKey( String::Format( "System\\CurrentControlSet\\Services\\EventLog\\{0}", e->Log ) );
      if ( regEventLog )
      {
         Object^ temp = regEventLog->GetValue( "File" );
         if ( temp != nullptr )
         {
            Console::WriteLine( "  Log file path = \t {0}", temp );
            FileInfo^ file = gcnew FileInfo( temp->ToString() );
            
            // Get the current size of the event log file.
            if ( file->Exists )
            {
               sizeKB = file->Length / 1024;
               if ( (file->Length % 1024) != 0 )
               {
                  sizeKB++;
               }
               Console::WriteLine( "  Current size = \t {0} kilobytes", sizeKB );
            }
         }
         else
         {
            Console::WriteLine( "  Log file path = \t <not set>" );
         }
      }
      
      // Display the maximum size and overflow settings.
      sizeKB = e->MaximumKilobytes;
      Console::WriteLine( "  Maximum size = \t {0} kilobytes", sizeKB );
      Console::WriteLine( "  Overflow setting = \t {0}", e->OverflowAction );
      switch ( e->OverflowAction )
      {
         case OverflowAction::OverwriteOlder:
            Console::WriteLine( "\t Entries are retained a minimum of {0} days.", e->MinimumRetentionDays );
            break;

         case OverflowAction::DoNotOverwrite:
            Console::WriteLine( "\t Older entries are not overwritten." );
            break;

         case OverflowAction::OverwriteAsNeeded:
            Console::WriteLine( "\t If number of entries equals max size limit, a new event log entry overwrites the oldest entry." );
            break;

         default:
            break;
      }
   }
}

static void DisplayEventLogProperties()
{
    // Iterate through the current set of event log files,
    // displaying the property settings for each file.

    EventLog[] eventLogs = EventLog.GetEventLogs();
    foreach (EventLog e in eventLogs)
    {
        Int64 sizeKB = 0;

        Console.WriteLine();
        Console.WriteLine("{0}:", e.LogDisplayName);
        Console.WriteLine("  Log name = \t\t {0}", e.Log);

        Console.WriteLine("  Number of event log entries = {0}", e.Entries.Count.ToString());

        // Determine if there is an event log file for this event log.
        RegistryKey regEventLog = Registry.LocalMachine.OpenSubKey("System\\CurrentControlSet\\Services\\EventLog\\" + e.Log);
        if (regEventLog != null)
        {
            Object temp = regEventLog.GetValue("File");
            if (temp != null)
            {
                Console.WriteLine("  Log file path = \t {0}", temp.ToString());
                FileInfo file = new FileInfo(temp.ToString());

                // Get the current size of the event log file.
                if (file.Exists)
                {
                    sizeKB = file.Length / 1024;
                    if ((file.Length % 1024) != 0)
                    {
                        sizeKB++;
                    }
                    Console.WriteLine("  Current size = \t {0} kilobytes", sizeKB.ToString());
                }
            }
            else
            {
                Console.WriteLine("  Log file path = \t <not set>");
            }
        }

        // Display the maximum size and overflow settings.

        sizeKB = e.MaximumKilobytes;
        Console.WriteLine("  Maximum size = \t {0} kilobytes", sizeKB.ToString());
        Console.WriteLine("  Overflow setting = \t {0}", e.OverflowAction.ToString());

        switch (e.OverflowAction)
        {
            case OverflowAction.OverwriteOlder:
                Console.WriteLine("\t Entries are retained a minimum of {0} days.",
                    e.MinimumRetentionDays);
                break;
            case OverflowAction.DoNotOverwrite:
                Console.WriteLine("\t Older entries are not overwritten.");
                break;
            case OverflowAction.OverwriteAsNeeded:
                Console.WriteLine("\t If number of entries equals max size limit, a new event log entry overwrites the oldest entry.");
                break;
            default:
                break;
        }
    }
}

Shared Sub DisplayEventLogProperties()

   ' Iterate through the current set of event log files,
   ' displaying the property settings for each file.
   Dim eventLogs As EventLog() = EventLog.GetEventLogs()
   
   Dim e As EventLog
   For Each e In  eventLogs
      Dim sizeKB As Int64 = 0
      
      Console.WriteLine()
      Console.WriteLine("{0}:", e.LogDisplayName)
      Console.WriteLine("  Log name = " + ControlChars.Tab _
                          + ControlChars.Tab + " {0}", e.Log)

      Console.WriteLine("  Number of event log entries = {0}", e.Entries.Count.ToString())
      
      ' Determine if there is an event log file for this event log.
      Dim regEventLog As RegistryKey
      regEventLog = Registry.LocalMachine.OpenSubKey( _
             ("System\CurrentControlSet\Services\EventLog\" + e.Log))

      If Not (regEventLog Is Nothing) Then

         Dim temp As Object = regEventLog.GetValue("File")
         If Not (temp Is Nothing) Then

            Console.WriteLine("  Log file path = " + ControlChars.Tab _
                                  + " {0}", temp.ToString())
            Dim file As New FileInfo(temp.ToString())
            
            ' Get the current size of the event log file.
            If file.Exists Then
               sizeKB = file.Length / 1024
               If file.Length Mod 1024 <> 0 Then
                  sizeKB += 1
               End If
               Console.WriteLine("  Current size = " + ControlChars.Tab _
                          + " {0} kilobytes", sizeKB.ToString())
            End If
         Else
            Console.WriteLine("  Log file path = " + ControlChars.Tab _
                             + " <not set>")
         End If
      End If
      
      ' Display the maximum size and overflow settings.
      sizeKB = e.MaximumKilobytes
      Console.WriteLine("  Maximum size = " + ControlChars.Tab _
                         + " {0} kilobytes", sizeKB.ToString())
      Console.WriteLine("  Overflow setting = " + ControlChars.Tab _
                         + " {0}", e.OverflowAction.ToString())
      
      Select Case e.OverflowAction
         Case OverflowAction.OverwriteOlder
            Console.WriteLine(ControlChars.Tab + _
                 " Entries are retained a minimum of {0} days.", _
                 e.MinimumRetentionDays)
         Case OverflowAction.DoNotOverwrite
            Console.WriteLine(ControlChars.Tab + _
                 " Older entries are not overwritten.")
         Case OverflowAction.OverwriteAsNeeded
            Console.WriteLine(ControlChars.Tab + _
                 " If number of entries equals max size limit, a new event log entry overwrites the oldest entry.")
         Case Else
      End Select

   Next e

End Sub

Remarks

Event logs grow in size as new events are written to them. Each event log has a configured maximum size limit; the MaximumKilobytes property defines the maximum number of kilobytes allowed for the event log file size.

Use the OverflowAction property value to examine the configured overflow behavior for an event log at its maximum size. Use the ModifyOverflowPolicy method to change the overflow behavior for an event log.

Note

The overflow behavior takes effect only when an event log reaches its maximum file size. The overflow behavior does not affect writing a new entry to a log that can accommodate additional event log entries.

See also

• OverflowAction
• MaximumKilobytes
• ModifyOverflowPolicy(OverflowAction, Int32)
• MinimumRetentionDays