Application Fundamentals

In the context of Microsoft Application Center 2000 (Application Center), an application is a manifest listing .NET resources that are synchronized within, or deployed to, a cluster. An application contains resources by listing references to them, thus more than one application can list the same resource. When you synchronize or deploy an Application Center application, the resources listed in the application are synchronized or deployed. The resources that can be added to an application include:

  • Web sites and virtual directories, which includes files, certificates, certificate trust lists (CTLs), and ISAPI filters referenced by the site/virtual directory.

  • COM+ applications (see the following Note).

  • File system directories and files.

  • System Data Source Names (DSNs).

  • Registry keys.

The following resources can be part of an Application Center application, but you cannot explicitly add or remove them to applications by using the Application Center snap-in or the command-line tool:

  • Exportable CAPI certificates.

  • Windows Management Instrumentation (WMI) monitoring settings (in the Application Center namespace, Microsoft Health Monitor 2.1 settings, and event filters).

  • Application Center monitors (listed in the synchronized monitors data group).

  • Metabase (Internet Information Services 5.0 [IIS] configuration) settings.

  • Global ISAPI filters (see the following Note).

Bb734890.note(en-us,TechNet.10).gif Note   Application Center does not synchronize or deploy user applications (for example, Microsoft Office). You must use another method, such as Microsoft Software Management Software, to perform these tasks.

Default Applications Created by Application Center

Application Center creates some default applications when you install it on a server. These applications are created automatically to simplify cluster administration and to ensure that your Web applications are synchronized automatically.

  • AllSites—this application contains all Web sites and virtual directories listed in the IIS metabase.

    You cannot delete or rename this application, nor can you add resources to it or remove resources from it. Any changes in the IIS metabase are automatically detected and added to AllSites.

  • Administration Web Site—this application contains the IIS administrative Web site and its associated virtual directories. You can rename or delete this application; however, AllSites still contains the administration Web site and its associated virtual directories.

    Bb734890.note(en-us,TechNet.10).gif Note   If have deleted this site prior to installing Application Center, this application is not created.

  • Application Center 2000 Administrative Web Site—this application contains the Application Center 2000 Administrative Web Site and its associated virtual directories. You can rename or delete this application; however, AllSites still contains the Application Center 2000 Administrative Web Site and its associated virtual directories.

  • Default Web Site—this application contains the Default Web Site and its associated virtual directories. You can rename or delete this application; however, AllSites still contains the Default Web Site and its associated virtual directories.

    Bb734890.note(en-us,TechNet.10).gif Note    Application Center creates an application for every site or virtual site on the server (using the name of the site) when it is installed; therefore, if you have deleted a site prior to installing Application Center, that application is not created.

User-Defined Applications

You can create your own applications to organize and facilitate synchronization and deployment according to your requirements. You can create an application that lists a subset of a default application or lists resources that are not listed in a default application.

Application Uses

You can use applications to manage synchronization or deployment for your .NET resources. Using applications in this way gives you more control over what resources are synchronized or deployed and when.

  • More granular control —if you have a large number of files in your Web applications and only a few of them are updated regularly, you can use applications to group these files so that they can be synchronized or deployed together, leaving the other files untouched.

    To synchronize only these applications, you must disable Automatic Updates and use advanced synchronization for these specific applications. You can also use synchronization with file exclusions; however, this might be impractical for large numbers of files or files that are in different locations on the hard disk.

    The default applications that are created by Application Center are an example of using applications that are a subset of another application for more granular control. The Administration Web Site, Application Center 2000 Administrative Web Site, and Default Web Site are all subsets of AllSites.

  • Special content situations—you can simplify COM+ applications deployment by putting them into an applications list and deploying all of them at once, rather than one at a time. This can be more efficient, because the Web Service must be restarted on the targets to deploy COM+ applications.

    Bb734890.note(en-us,TechNet.10).gif Notes

    Another example of special content are files that are not part of a Web application, but need to be deployed and synchronized.

Application Resources

You can add any of the following resources to an application as specified.

  • Web sites or virtual directories—when specifying these, you need to add only the Web site or virtual directory. You do not need to specify the physical directories or files that make up the Web site or virtual directory explicitly. Application Center includes the resources referenced by the Web site or virtual directory.

    Bb734890.note(en-us,TechNet.10).gif Note   Application Center only synchronize resources that are specified on the local file system and does not synchronize resources that are specified with a UNC path or on a removable media.

  • COM+ applications—you can add only COM+ applications that are properly registered with Component Services on the local server. If a COM+ application does not appear in the Application Center snap-in, you cannot add it to an application. To add COM components to application lists, you must install them into COM+ applications.

    Bb734890.note(en-us,TechNet.10).gif Notes

  • File system directories and files—you can add these as required.

    Bb734890.note(en-us,TechNet.10).gif Notes

  • DSNs—only DSNs on the local server are available to add to applications. DSNs on remote servers are not available until you create them on the local server.

  • Registry keys—you can add any registry key to an application; however, use caution when doing so, because changes to the registry can result in unwanted behavior.

You cannot add the following directly to an application, but they are synchronized and deployed as noted:

  • ISAPI filters—you can synchronize or deploy global and per-virtual directory ISAPI filters. Per-virtual directory ISAPI filters are synchronized or deployed with their associated virtual directory automatically. Use the New Deployment Wizard to synchronize or deploy global ISAPI filters.

  • Certificates—to use X.509 certificates, the private key must be exportable. X.509 certificates are synchronized or deployed with their associated Web sites automatically. Also, the X.509 certificate must be for server authentication and be bound to a name that is valid across the cluster. A good choice for this is the cluster's shared DNS name.

  • Network settings and some metabase settings—if you are using Network Load Balancing (NLB), these are synchronized automatically as part of the system definition (information that Application Center requires for managing the cluster), even if Automatic Updates are disabled.

COM + Applications and Global ISAPI Filters

Application Center synchronization protects cluster availability by preventing certain components from being synchronized across the cluster automatically. For example, when you deploy a new or updated COM+ application or global ISAPI filter, the Web Service on the target must be restarted. To prevent potential down time, Application Center synchronizes or deploys COM+ applications and global ISAPI filters only when you use the New Deployment Wizard. By using the wizard, you can have granular control over the deployment settings.

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