Unlike Model to Model comparisons, which compare one ideal installation to another, Model to Install comparisons compare the actual state of the installed component or components at deployment time against their current state. You can specify that this comparison compares the model to hosts, host sets, or to component level.
A Model to Install comparison uses snapshot information to compare a component's just-installed state with its current state. A snapshot is a record of the state of an installed component immediately after it has been deployed to a host. The component's XML model includes parameters that control the scope of this snapshot. For example, the XML model can list files, such as log files, that should be ignored during a comparison.
When the provisioning software performs a Model to Install comparison, the Master Server looks up the list of snapshots for all the components being compared. It sends this list to the Remote Agent on the host where the components are installed. The snapshot information includes rules for any files and directories that should be ignored during the comparison. The Remote Agent then processes these rules. Both Master Server and Remote Agents must be using the same locale for the Model to Install comparison to function properly.
Model to Install Comparison Characteristics
Compares a snapshot of installed components with the current state of the components
Allows the flexibility of comparing either an individual component or any set of components installed on a host
Compares at a high level (component and directory lists) or a low level (file contents)
Processes comparison on the Remote Agent
Requires that components created snapshots when installed on a Remote Agent.
You will want to use a Model to Install comparison in the following situation.
If a configuration was working as expected and is no longer working, you might want to determine if there have been out-of-band changes.
A Model to Install comparison compares a component model to a specific installation of a component. This section describes how a component type effects a Model to Install comparison.
During a snapshot, the current state of the metabase is exported into an XML file. During a Model to Install comparison, the metabase is re-exported and compared against the original XML file.
During a snapshot, the current state of the metabase is exported into an XML file. During a Model to Install comparison, the metabase is re-exported and compared against the original XML file. The standard XML differentiator is used to generate differences between these files.
The COM+ Application is re-exported on the target system as an MSI file and compared against the MSI file used to install the application. A Model to Install comparison will only indicate that there were differences (that is, the two binary files are different). It will not indicate the details of the differences.
The COM component is compared as a binary file against the file used during installation. A Model to Install comparison will only indicate that there were differences (that is, the two binary files are different). It will not indicate the details of the differences.
During a snapshot, the current state of registry key (and its children) is exported into an XML file. During a Model to Install comparison, the registry key is re-exported and compared against the original XML file. The standard XML differentiator is used to generate differences between these files.
Model to Install comparisons are not supported for *.reg files. Snapshots are not taken during installation. Without a snapshot, there is nothing to compare in a Model to Install comparison. If you need to compare registry changes, use the built-in Registry keys type.
Model to Install comparisons are not supported for Windows Installer files. Snapshots are not taken during installation. Without a snapshot, there is nothing to compare in a Model to Install comparison. Since the provisioning system does not have first-hand knowledge of the actions taken during the installation, it cannot determine what needs to be captured.
Model to Install comparisons are not supported for Windows Batch files. Snapshots are not taken during installation. Without a snapshot, there is nothing to compare in a Model to Install comparison.
Model to Install comparisons are not supported for WSH files. Snapshots are not taken during installation. Without a snapshot, there is nothing to compare in a Model to Install comparison.
Model to Install comparisons with WebLogic WAR Files use the standard file and directory approach.
The relevant settings for the application will be exported into a file, which will be compared to the file that contained the settings during deployment.
Model to Install comparisons with WebLogic JAR Files use the standard file and directory approach.
The relevant settings for the EJB will be exported into a file, which will be compared to the file that contained the settings during deployment.
Model to Install comparisons with WebLogic EAR Files use the standard file and directory approach.
The relevant settings for the Application will be exported into a file, which will be compared to the file that contained the settings during deployment.
This procedure describes creating a comparison by using the browser interface. You can also create comparisons by using the following command.
cmp.ds.add – Creates a new comparison.
For a detailed description of this command, see Chapter 5, cmp: CLI Commands for Running Comparisons, in N1 Grid Service Provisioning System 5.0 Command-Line Interface Reference Manual.
The Remote Agents from each host must be set to use the same locale for Install to Install comparisons to function properly.
To create a new comparison, you must belong to a user group that has Create, Edit, Delete permission on comparisons.
In the navigation menu, click Comparisons.
The Comparisons page is displayed.
Type the name and description of the comparison you want to create and click Create.
The comparison's Details page is displayed.
In the Style of Comparison area, click Model to Install.
Select the level of detail that the comparison will use.
Directory and File properties. Confirms that both hosts have the same files and directories and that the files and directories are the same sizes.
File Contents. Compares the contents of files on both hosts.
If the component you are using in a comparison includes its own rules about files to ignore, those rules are used in addition to any ignore rules you define for this comparison.
Select the scope of the comparison.
(Optional) Type the names of files or directories that you want the comparison to ignore.
This feature allows the provisioning system to accommodate changes to things like log files without causing the comparison to fail.
For more information, see Modifying Directories or Files to Ignore During Comparisons.
In the Limits area, specify the maximum number of hours or minutes the comparison can run.
By default, comparisons are allowed to run for 4 hours.
If the comparison times out, an error message will display on the Comparisons page.
Choose to save the comparison to run later or run it now.