Resource dynamic-link libraries (DLLs) in clusters running Windows Server 2003

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Resource dynamic-link libraries (DLLs)

This topic provides a brief description of resource DLLs in server clusters running Windows Server 2003.

Resource DLLs contain instructions that manage cluster resources of one or more types. The most important role of the resource DLL is to detect application failures.

When the Cluster service issues a request to a resource, that request is passed to the Resource Monitor. The Resource Monitor, in turn, calls an entry point function in the resource DLL responsible for the resource.

Windows Server 2003, Enterprise Edition and Windows Server 2003, Datacenter Edition define several resource types and provide resource DLLs to manage them. However, a server cluster is not limited to the resource types provided with the operating system. Developers can create their own resource DLLs to replace or augment the resource DLLs provided with the operating system. Custom resource DLLs have detailed knowledge of the resources they manage and are used by resource monitors to determine the resource state (dead/alive).