ClusterEnum function (clusapi.h)

Article
10/13/2021

Enumerates the cluster objects in a cluster, returning the name of one object with each call. The PCLUSAPI_CLUSTER_ENUM type defines a pointer to this function.

Syntax

DWORD ClusterEnum(
  [in]      HCLUSENUM hEnum,
  [in]      DWORD     dwIndex,
  [out]     LPDWORD   lpdwType,
  [out]     LPWSTR    lpszName,
  [in, out] LPDWORD   lpcchName
);

Parameters

[in] hEnum

A cluster enumeration handle returned by the ClusterOpenEnum function.

[in] dwIndex

The index used to identify the next entry to be enumerated. This parameter should be zero for the first call to ClusterEnum and then incremented for subsequent calls.

[out] lpdwType

A pointer to the type of object returned. One of the following values of the CLUSTER_ENUM enumeration is returned with each call.

CLUSTER_ENUM_NODE (1 (0x1))

Enumerates the nodes in the cluster.

CLUSTER_ENUM_RESTYPE (2 (0x2))

Enumerates the resource types in the cluster.

CLUSTER_ENUM_RESOURCE (4 (0x4))

Enumerates the resources in the cluster.

CLUSTER_ENUM_GROUP (8 (0x8))

Enumerates the groups in the cluster.

CLUSTER_ENUM_NETWORK (16 (0x10))

Enumerates the networks in the cluster.

CLUSTER_ENUM_NETINTERFACE (32 (0x20))

Enumerates the network interfaces in the cluster.

CLUSTER_ENUM_SHARED_VOLUME_RESOURCE (1073741824 (0x40000000))

Enumerates the cluster shared volumes used by the cluster.

Note Unlike most other enumeration bitmasks, this value must be used alone. Do not use the OR operator to combine it with other bitmasks.

Windows Server 2008: The CLUSTER_ENUM_SHARED_VOLUME_RESOURCE value is not supported before Windows Server 2008 R2.

CLUSTER_ENUM_INTERNAL_NETWORK (2147483648 (0x80000000))

Enumerates the networks used by the cluster for internal communication. The networks are enumerated in order of highest-to-lowest priority as established by the SetClusterNetworkPriorityOrder function.

Note Unlike most other enumeration bitmasks, this value must be used alone. Do not use the OR operator to combine it with other bitmasks.

CLUSTER_ENUM_ALL ((CLUSTER_ENUM_NODE | CLUSTER_ENUM_RESTYPE | CLUSTER_ENUM_RESOURCE | CLUSTER_ENUM_GROUP | CLUSTER_ENUM_NETWORK | CLUSTER_ENUM_NETINTERFACE))

Enumerates all cluster objects.

[out] lpszName

A pointer to a null-terminated Unicode string containing the name of the returned object.

[in, out] lpcchName

A pointer to the size of the lpszName buffer as a count of characters. On input, specify the maximum number of characters the buffer can hold, including the terminating NULL. On output, specifies the number of characters in the resulting name, excluding the terminating NULL.

Return value

The function returns one of the following values.

Return code/value	Description
ERROR_SUCCESS 0	The operation completed successfully.
ERROR_NO_MORE_ITEMS 259 (0x103)	No more data is available. This value is returned if there are no more objects of the requested type to be returned.
ERROR_MORE_DATA 234 (0xEA)	More data is available. This value is returned if the buffer pointed to by lpszName is not big enough to hold the result. The lpcchName parameter returns the number of characters in the result, excluding the terminating NULL.

Remarks

The ClusterEnum function is typically used to iterate through a collection of cluster objects of one or more types. If, for example, an application wants to enumerate all of the nodes in a cluster, it calls ClusterOpenEnum to open a cluster enumerator that can process nodes. The dwType parameter is set to CLUSTER_ENUM_NODE to specify nodes as the object type to be enumerated. If the application enumerates groups in addition to nodes, the dwType parameter is set to CLUSTER_ENUM_NODE | CLUSTER_ENUM_GROUP. With the handle that ClusterOpenEnum returns, the application calls ClusterEnum repeatedly to retrieve each of the objects. The lpdwType parameter points to the type of object that is retrieved.

Note that lpcchName refers to a count of characters and not a count of bytes, and that the returned size does not include the terminating NULL in the count. For more information on sizing buffers, see Data Size Conventions.

Examples

See Enumerating Objects.

Requirements

Requirement	Value
Minimum supported client	None supported
Minimum supported server	Windows Server 2008 Enterprise, Windows Server 2008 Datacenter
Target Platform	Windows
Header	clusapi.h
Library	ClusAPI.lib
DLL	ClusAPI.dll