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Specifies how to handle entries in an event log that has reached its maximum file size.
public enum class OverflowAction
public enum OverflowAction
type OverflowAction =
Public Enum OverflowAction
Name | Value | Description |
---|---|---|
DoNotOverwrite | -1 | Indicates that existing entries are retained when the event log is full and new entries are discarded. |
OverwriteAsNeeded | 0 | Indicates that each new entry overwrites the oldest entry when the event log is full. |
OverwriteOlder | 1 | This field is deprecated. |
The following example enumerates the event logs defined on the local computer and displays configuration details for each event log.
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
Every event log has a maximum size limit and a configurable setting that provides the rule for writing new entries at that limit. When the event log has reached its maximum size, you can specify one of the following rules:
New entries will be discarded.
New entries will overwrite older entries.
Use the ModifyOverflowPolicy method to set the overflow behavior for an EventLog. Check the current configured behavior of an EventLog through its OverflowAction property.
Warning
The OverwriteOlder
behavior is deprecated. Using this value might cause the Event Log to behave as if the DoNotOverwrite
value was used instead, which will cause events to be discarded when the log is full.
Product | Versions |
---|---|
.NET | 8 (package-provided), 9 (package-provided), 10 (package-provided) |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1 |
.NET Standard | 2.0 (package-provided) |
Windows Desktop | 3.0, 3.1, 5, 6, 7, 8, 9, 10 |
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