A Cluster Administrator extension DLL must be registered for each computer that is running Cluster Administrator. There are two parts to the registration:
To register a Cluster Administrator extension with a cluster, implement the DllRegisterCluAdminExtension entry point function. DllRegisterCluAdminExtension creates or modifies the AdminExtensions property for the resource type supported by the extension. DllRegisterCluAdminExtension is exported only by Cluster Administrator extensions.
To register a Cluster Administrator extension with the COM library, implement the DllRegisterServer entry point function. DllRegisterServer registers the extension by creating two new keys in the system registry: a key for the ProgId below HKEY_CLASSES_ROOT and a key for the CLSID below HKEY_CLASSES_ROOT\CLSID. DllRegisterServer is exported by all COM servers.
Applications that need to register an extension should call a program named REGCLADM.EXE. REGCLADM calls both the DllRegisterCluAdminExtension and DllRegisterServer entry point functions to take care of both types of registration. Setup programs that need to register extension DLLs must be modified to also call these entry point functions. However, if the setup program is run on a non-cluster node, only the COM registration must be performed. Cluster registration should occur only when the extension is running on a node in a cluster.
Because it is necessary at times to cancel registration, the Cluster Administrator Extension API defines two entry point functions for that purpose: DllUnregisterCluAdminExtension and DllUnregisterServer. As with DllRegisterCluAdminExtension, DllUnregisterCluAdminExtension is specific to Cluster Administrator extensions. As with DllRegisterServer, DllUnregisterServer is exported by all COM servers.
The following table briefly describes the two registration functions and the functions that can be used to cancel registration:
| Function | Description |
|---|---|
| DllRegisterCluAdminExtension | Registers a Cluster Administrator extension DLL with the cluster by adding information to the cluster database. |
| DllRegisterServer | Registers a Cluster Administrator extension DLL with COM by adding information to the Microsoft® Windows NT® system registry. |
| DllUnregisterCluAdminExtension | Cancels the registration of a Cluster Administrator extension DLL with the cluster by removing information from the cluster database. |
| DllUnregisterServer | Cancels the registration of a Cluster Administrator extension DLL with COM by removing information from the Windows NT system registry. |