Using IIS 7 Configuration History

Introduction

In IIS 6.0, administrators had a safety net that allowed them to easily ascertain what changed in IIS's configuration. It was implemented as a history file that could be restored easily as well serving as a usable history of events that happened to your configuration. In case anything went wrong during application installs, upgrades, or individual changes to the metabase, you can restore to a working state.

With IIS7's brand new configuration, we wanted the same "safety net" yet we couldn't use the IIS 6.0 history feature because of changes in our configuration architecture. In IIS 7.0 we have resolved this problem by creating a service that monitors for changes to the master configuration file, ApplicationHost.config, and will periodically create snapshots for you to later retrieve if necessary.

This feature is called IIS7's Configuration History. In this walkthrough, we will illustrate how this feature works.

Tasks in this walkthrough

• Reviewing configHistory default configuration settings
• Validating configHistory functionality is working properly
• Modifying the number of configuration directories (maxHistories) retained and period attributes
• Changing the default path for configHistory
• Restoring configuration from a backup file

Task 1: Reviewing configHistory default configuration settings

In this task, you will review the configuration options available after a default IIS7 installation. In later tasks, you will later modify some of these settings to show the flexibility of this feature to fit your environment.

Step 1: Open applicationHost.config

1. Click Start, click Run, and in the Open: dialog box type notepad and Click OK
   
   Figure 1: Opening Configuration with Notepad
2. Click File, then open, and in the File name: dialog box type %windir%\system32\inetsrv\config\applicationHost.config and Click Open
   
   Figure 2: ApplicationHost.config Path
3. To locate configHistory section, click CTRL-F and enter configHistory and Click Find Next

After opening the master file, you should see an entry like the following for configHistory:

<sectionGroup name"system.applicationHost>

    <section name="applictionPools" allowDefinition="AppHostOnly" overrideMode="Deny" />

    <section name="configHistory" allowDefinition="AppHostOnly" overrideModeDefault="Deny" />

       <section name="customMetadata" allowDefinition="AppHostOnly" overrideModeDefault="Deny" /> 

       <section name="listenerAdapters" allowDefinition="AppHostOnly" overrideModeDefault="Deny" /> 

       <section name="log" allowDefinition="AppHostOnly" overrideModeDefault="Deny" /> 

       <section name="sites" allowDefinition="AppHostOnly" overrideModeDefault="Deny" /> 

       <section name="webLimits" allowDefinition="AppHostOnly" overrideModeDefault="Deny" /> 

</sectionGroup>

You will quickly notice that there are no further settings for this feature in applicationHost.config. This is expected behavior because by default IIS7 uses the values stored in the IIS7 schema. To see the default settings, we will open IIS7's schema file (IIS_schema.xml.)

Step 2: Locate configHistory defaults in IIS schema

1. Click Start, click Run, and in the Open: dialog box type notepad and Click OK
2. Click File, then open, and in the File name: dialog box type %windir%\system32\inetsrv\config\schema\iis_schema.xml
   
   Figure 3: IIS Schema 
3. To locate configHistory section, click CTRL-F and enter configHistory
4. On your Windows Server Code Name "Longhorn" server, you should see the following:
   
   

   Figure 4: configHistory Schema Definition 

   As you can see, there are four configurable settings (attributes) for the configHistory section:

   Attribute	Default Setting	Definition
   enabled	True	This value indicates whether configuration history is enabled or disables
   path	%systemdrive%\inetpub\history	The path where history directories will be created and stored
   maxHistories	10	The maximum number of directories retained by IIS7
   period	00:02:00	The time between each check made for changes by IIS7