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Log <log>

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Overview

The <log> element specifies several global logging options for Internet Information Services (IIS) 7. For example, the centralLogFileMode attribute specifies whether site-level logging, central W3C logging, or central binary logging is enabled.

Site-level logging creates individual log file directories for each site on your server, where each folder contains only the log files for that site. Central logging enables the use of a single log file for all sites for the time period specified by the period attribute for the <centralBinaryLogFile> or <centralW3CLogFile> element. The time period can be daily, weekly, monthly, hourly, or a maximum file size.

Note

Log files in W3C format are text-based files that most log-parsing utilities can process. Binary log files use a proprietary storage format that requires the use of an application that can process log files in that format, such as Microsoft's LogParser utility.

Compatibility

Version Notes
IIS 10.0 The <log> element was not modified in IIS 10.0.
IIS 8.5 The <log> element was not modified in IIS 8.5.
IIS 8.0 The <log> element was not modified in IIS 8.0.
IIS 7.5 The <log> element was not modified in IIS 7.5.
IIS 7.0 The <log> element was introduced in IIS 7.0.
IIS 6.0 The <log> element replaces the following IIS 6.0 attributes:
  • CentralBinaryLoggingEnabled
  • CentralW3CLoggingEnabled
  • LogInUTF8

Setup

The <log> element is included in the default installation of IIS 7.

How To

How to enable central binary logging for a server

  1. Open Internet Information Services (IIS) Manager:

    • If you are using Windows Server 2012 or Windows Server 2012 R2:

      • On the taskbar, click Server Manager, click Tools, and then click Internet Information Services (IIS) Manager.

    • If you are using Windows 8 or Windows 8.1:

      • Hold down the Windows key, press the letter X, and then click Control Panel.
      • Click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.

    • If you are using Windows Server 2008 or Windows Server 2008 R2:

      • On the taskbar, click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.

    • If you are using Windows Vista or Windows 7:

      • On the taskbar, click Start, and then click Control Panel.
      • Double-click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.

  2. In the Connections pane, click the server name.

  3. In the server's Home pane, double-click Logging.
    Screenshot of Logging selected in the SERVER Home pane.

  4. On the Logging page, under One log file per, select Server from the drop-down list, then choose Binary from the Format drop-down list.
    Screenshot of setting One log file per Server and Log File Format to Binary in the Logging pane.

  5. Click Apply in the Actions pane.

How to enable central W3C logging for a server

  1. Open Internet Information Services (IIS) Manager:

    • If you are using Windows Server 2012 or Windows Server 2012 R2:

      • On the taskbar, click Server Manager, click Tools, and then click Internet Information Services (IIS) Manager.

    • If you are using Windows 8 or Windows 8.1:

      • Hold down the Windows key, press the letter X, and then click Control Panel.
      • Click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.

    • If you are using Windows Server 2008 or Windows Server 2008 R2:

      • On the taskbar, click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.

    • If you are using Windows Vista or Windows 7:

      • On the taskbar, click Start, and then click Control Panel.
      • Double-click Administrative Tools, and then double-click Internet Information Services (IIS) Manager.

  2. In the Connections pane, click the server name.

  3. In the server's Home pane, double-click Logging.
    Screenshot of the Logging icon selected in the SERVER Home pane.

  4. On the Logging page, under One log file per, select Server from the drop-down list, then choose W3C from the Format drop-down list.
    Screenshot of setting One log file per Server and Log File Format to W 3 C in the Logging pane.

  5. Click Apply in the Actions pane.

Configuration

Attributes

Attribute Description
centralLogFileMode Optional enum attribute.

Specifies the central logging mode for the server.

The centralLogFileMode attribute can have one of the following possible values. The default is Site.
Value Description
Site Configures all sites to use site logging instead of central logging. This is the default setting.

The numerical value is 0.
CentralBinary Creates one log file for all Web sites on a Web server. The data in the log file is binary-based, unformatted data that is not customizable.

The numerical value is 1.
CentralW3C Logs requests for all sites on a Web server to a single central log file in a text-based, customizable ASCII format.

The numerical value is 2.
logInUTF8 Optional Boolean attribute.

Specifies whether IIS should log all strings in UCS Transformation Format 8 (UTF-8). This setting applies server-wide to all text-mode logging.

The default value is true.

Child Elements

Element Description
centralBinaryLogFile Optional element.

Specifies the central binary log settings for all sites on a server.
centralW3CLogFile Optional element.

Specifies the central W3C log settings for all sites on a server.

Configuration Sample

The following configuration sample specifies that IIS will use site-level logging.

<log centralLogFileMode="Site">
   <centralBinaryLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" />
   <centralW3CLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" />
</log>

The following configuration sample specifies that IIS will use central binary logging, and configures binary log file rotation on a daily basis.

<log centralLogFileMode="CentralBinary">
   <centralBinaryLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" period="Daily" />
   <centralW3CLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" />
</log>

The following configuration sample specifies that IIS will use central W3C logging, and configures W3C log file rotation on a daily basis.

<log centralLogFileMode="CentralW3C">
   <centralBinaryLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" />
   <centralW3CLogFile enabled="true" directory="%SystemDrive%\inetpub\logs\LogFiles" period="Daily" />
</log>

Sample Code

The following code samples specify that IIS will use central binary logging, and configure binary log file rotation on a daily basis.

AppCmd.exe

appcmd.exe set config -section:system.applicationHost/log /centralLogFileMode:"CentralBinary" /commit:apphost

appcmd.exe set config -section:system.applicationHost/log /centralBinaryLogFile.period:"Daily" /commit:apphost

Note

You must be sure to set the commit parameter to apphost when you use AppCmd.exe to configure these settings. This commits the configuration settings to the appropriate location section in the ApplicationHost.config file.

C#

using System;
using System.Text;
using Microsoft.Web.Administration;

internal static class Sample
{
   private static void Main()
   {
      using (ServerManager serverManager = new ServerManager())
      {
         Configuration config = serverManager.GetApplicationHostConfiguration();

         ConfigurationSection logSection = config.GetSection("system.applicationHost/log");
         logSection["centralLogFileMode"] = @"CentralBinary";
         ConfigurationElement centralBinaryLogFileElement = logSection.GetChildElement("centralBinaryLogFile");
         centralBinaryLogFileElement["period"] = @"Daily";

         serverManager.CommitChanges();
      }
   }
}

VB.NET

Imports System
Imports System.Text
Imports Microsoft.Web.Administration

Module Sample

   Sub Main()
      Dim serverManager As ServerManager = New ServerManager
      Dim config As Configuration = serverManager.GetApplicationHostConfiguration

      Dim logSection As ConfigurationSection = config.GetSection("system.applicationHost/log")
      logSection("centralLogFileMode") = "CentralBinary"
      Dim centralBinaryLogFileElement As ConfigurationElement = logSection.GetChildElement("centralBinaryLogFile")
      centralBinaryLogFileElement("period") = "Daily"

      serverManager.CommitChanges()
   End Sub

End Module

JavaScript

var adminManager = new ActiveXObject('Microsoft.ApplicationHost.WritableAdminManager');
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST";

var logSection = adminManager.GetAdminSection("system.applicationHost/log", "MACHINE/WEBROOT/APPHOST");
logSection.Properties.Item("centralLogFileMode").Value = "CentralBinary";
var centralBinaryLogFileElement = logSection.ChildElements.Item("centralBinaryLogFile");
centralBinaryLogFileElement.Properties.Item("period").Value = "Daily";

adminManager.CommitChanges();

VBScript

Set adminManager = WScript.CreateObject("Microsoft.ApplicationHost.WritableAdminManager")
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST"

Set logSection = adminManager.GetAdminSection("system.applicationHost/log", "MACHINE/WEBROOT/APPHOST")
logSection.Properties.Item("centralLogFileMode").Value = "CentralBinary"
Set centralBinaryLogFileElement = logSection.ChildElements.Item("centralBinaryLogFile")
centralBinaryLogFileElement.Properties.Item("period").Value = "Daily"

adminManager.CommitChanges()

The following code samples specify that IIS will use central W3C logging, and configure W3C log file rotation on a daily basis.

AppCmd.exe

appcmd.exe set config -section:system.applicationHost/log /centralLogFileMode:"CentralW3C" /commit:apphost

appcmd.exe set config -section:system.applicationHost/log /centralW3CLogFile.period:"Daily" /commit:apphost

Note

You must be sure to set the commit parameter to apphost when you use AppCmd.exe to configure these settings. This commits the configuration settings to the appropriate location section in the ApplicationHost.config file.

C#

using System;
using System.Text;
using Microsoft.Web.Administration;

internal static class Sample
{
   private static void Main()
   {
      using (ServerManager serverManager = new ServerManager())
      {
         Configuration config = serverManager.GetApplicationHostConfiguration();

         ConfigurationSection logSection = config.GetSection("system.applicationHost/log");
         logSection["centralLogFileMode"] = @"CentralW3C";
         ConfigurationElement centralW3CLogFileElement = logSection.GetChildElement("centralW3CLogFile");
         centralW3CLogFileElement["period"] = @"Daily";

         serverManager.CommitChanges();
      }
   }
}

VB.NET

Imports System
Imports System.Text
Imports Microsoft.Web.Administration

Module Sample

   Sub Main()
      Dim serverManager As ServerManager = New ServerManager
      Dim config As Configuration = serverManager.GetApplicationHostConfiguration

      Dim logSection As ConfigurationSection = config.GetSection("system.applicationHost/log")
      logSection("centralLogFileMode") = "CentralW3C"
      Dim centralW3CLogFileElement As ConfigurationElement = logSection.GetChildElement("centralW3CLogFile")
      centralW3CLogFileElement("period") = "Daily"

      serverManager.CommitChanges()
   End Sub

End Module

JavaScript

var adminManager = new ActiveXObject('Microsoft.ApplicationHost.WritableAdminManager');
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST";

var logSection = adminManager.GetAdminSection("system.applicationHost/log", "MACHINE/WEBROOT/APPHOST");
logSection.Properties.Item("centralLogFileMode").Value = "CentralW3C";
var centralW3CLogFileElement = logSection.ChildElements.Item("centralW3CLogFile");
centralW3CLogFileElement.Properties.Item("period").Value = "Daily";

adminManager.CommitChanges();

VBScript

Set adminManager = WScript.CreateObject("Microsoft.ApplicationHost.WritableAdminManager")
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST"

Set logSection = adminManager.GetAdminSection("system.applicationHost/log", "MACHINE/WEBROOT/APPHOST")
logSection.Properties.Item("centralLogFileMode").Value = "CentralW3C"
Set centralW3CLogFileElement = logSection.ChildElements.Item("centralW3CLogFile")
centralW3CLogFileElement.Properties.Item("period").Value = "Daily"

adminManager.CommitChanges()