Default Log File Settings for Web Sites <logFile>

The <logFile> element of the <siteDefaults> element contains attributes that allow you to configure default logging for a site on IIS 7 and later.

For example, you can enable or disable logging, configure the format of the IIS log file, specify the categories of information to store in the log file, and change the directory where the log file is stored. You can also use the <logFile> element to control how often IIS creates a new log file based either on log file size or time interval and the maximum size (in bytes) that a log file can become.

By default, IIS 7 and later uses the World Wide Web Consortium (W3C) log file format. You can change this setting by modifying the logFormat attribute to IIS, NCSA, or Custom.

• Setting the ODBC logging attributes in the <odbcLogging> element. These attributes specify the System Data Source Name (DSN), table name, user name, and password for the ODBC connection.
• Setting the correct custom logging attributes in <logFile> element. These attributes must set the log file format to "Custom" and the custom log plug-in class ID to "{FF16065B-DE82-11CF-BC0A-00AA006111E0}".

For more information about ODBC logging, see the <odbcLogging> element.

You can define the categories of information that IIS logs by editing the logExtFileFlags attribute. The default values are Date, Time, ClientIP, UserName, ServerIP, Method, UriStem, UriQuery, TimeTaken, HttpStatus, Win32Status, ServerPort, UserAgent, HttpSubStatus, and Referer.

IIS 8.5 enables you to log custom fields in addition to the standard logged set. The log file format must be W3C to add custom fields. For more information, see customFields.

The <logFile> element is included in the default installation of IIS 7 and later.

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 on which you want to configure logging.

3. In the Home pane, double-click Logging.
   

4. In the Logging pane, select the log file format in the Format box, and then type the path to the directory where you store the log files in the Directory box or click Browse... to choose the directory in which to store the log files.
   

5. If you choose to use the W3C log file format:

   • Click Select Fields to choose the types of information to log.
   • In the W3C Logging Fields dialog box, select the check boxes for options you want to log, clear the check boxes for options you do not want to log, and then click OK.
     

1. Open Internet Information Services (IIS) Manager:

   • If you are using 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 8.1:

     • 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.

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

3. In the site's home pane, double-click Logging.

4. In the Logging home page, for Log Event Destination, select Log file only, ETW event only, or Both log file and ETW event.

   

1. Open Internet Information Services (IIS) Manager:

   • If you are using 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 8.1:

     • 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.

2. In the Connections pane, select the server, and then double-click Configuration Editor.

3. In the Configuration Editor, for the Section, expand system.applicationHost, and then select sites.

4. Expand siteDefaults, and then expand logFile.

5. For flushByEntryCountW3Clog, enter the number of events to be stored in the buffer before they are flushed to the log file.

6. In the Action pane, click Apply.

   

1. Open Internet Information Services (IIS) Manager:

   • If you are using 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 8.1:

     • 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.

2. In the Connections pane, expand the server, and then double-click Configuration Editor.

3. In the Configuration Editor, for the Section, expand system.applicationHost, and then select sites.

4. Expand siteDefaults, and then expand logFile.

5. For maxLogLineLength, enter the maximum number of bytes in a single line of a log file.

6. In the Action pane, click Apply.

   

The following configuration sample specifies default logFile options.

<system.applicationHost>
   <sites>
      <siteDefaults>
         <logFile logFormat="W3C"
            directory="%SystemDrive%\inetpub\logs\LogFiles"
            enabled="true">
            <customFields>
               <clear/>
               <add logFieldName="ContosoField" sourceName="ContosoSource"
                  sourceType="ServerVariable" />
            </customFields>
         </logFile>
      </siteDefaults>
   </sites>
</system.applicationHost>

The following code samples configure the default logFile options for IIS 7.

appcmd.exe set config -section:system.applicationHost/sites /siteDefaults.logFile.enabled:"True" /commit:apphost
appcmd.exe set config -section:system.applicationHost/sites /siteDefaults.logFile.logFormat:"W3C" /commit:apphost
appcmd.exe set config -section:system.applicationHost/sites /siteDefaults.logFile.directory:"%SystemDrive%\inetpub\logs\LogFiles" /commit:apphost

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 sitesSection = config.GetSection("system.applicationHost/sites");
         ConfigurationElement siteDefaultsElement = sitesSection.GetChildElement("siteDefaults");

         ConfigurationElement logFileElement = siteDefaultsElement.GetChildElement("logFile");
         logFileElement["logFormat"] = @"W3C";
         logFileElement["directory"] = @"%SystemDrive%\inetpub\logs\LogFiles";
         logFileElement["enabled"] = true;

         serverManager.CommitChanges();
      }
   }
}

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 sitesSection As ConfigurationSection = config.GetSection("system.applicationHost/sites")
      Dim siteDefaultsElement As ConfigurationElement = sitesSection.GetChildElement("siteDefaults")

      Dim logFileElement As ConfigurationElement = siteDefaultsElement.GetChildElement("logFile")
      logFileElement("logFormat") = "W3C"
      logFileElement("directory") = "%SystemDrive%\inetpub\logs\LogFiles"
      logFileElement("enabled") = True

      serverManager.CommitChanges()
   End Sub

End Module

var adminManager = new ActiveXObject('Microsoft.ApplicationHost.WritableAdminManager');
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST";
var sitesSection = adminManager.GetAdminSection("system.applicationHost/sites", "MACHINE/WEBROOT/APPHOST");
var siteDefaultsElement = sitesSection.ChildElements.Item("siteDefaults");

var logFileElement = siteDefaultsElement.ChildElements.Item("logFile");
logFileElement.Properties.Item("logFormat").Value = "W3C";
logFileElement.Properties.Item("directory").Value = "%SystemDrive%\\inetpub\\logs\\LogFiles";
logFileElement.Properties.Item("enabled").Value = true;

adminManager.CommitChanges();

Set adminManager = WScript.CreateObject("Microsoft.ApplicationHost.WritableAdminManager")
adminManager.CommitPath = "MACHINE/WEBROOT/APPHOST"
Set sitesSection = adminManager.GetAdminSection("system.applicationHost/sites", "MACHINE/WEBROOT/APPHOST")
Set siteDefaultsElement = sitesSection.ChildElements.Item("siteDefaults")

Set logFileElement = siteDefaultsElement.ChildElements.Item("logFile")
logFileElement.Properties.Item("logFormat").Value = "W3C"
logFileElement.Properties.Item("directory").Value = "%SystemDrive%\inetpub\logs\LogFiles"
logFileElement.Properties.Item("enabled").Value = True

adminManager.CommitChanges()