1.1 Glossary

This document uses the following terms:

active node: A node that is currently successfully executing the implementation-specific server-to-server protocols that constitute participation in a cluster.

authentication level: A numeric value indicating the level of authentication or message protection that remote procedure call (RPC) will apply to a specific message exchange. For more information, see [C706] section 13.1.2.1 and [MS-RPCE].

Authentication Service (AS): A service that issues ticket granting tickets (TGTs), which are used for authenticating principals within the realm or domain served by the Authentication Service.

basic volume: A partition on a basic disk.

characteristic: A read-only, intrinsic attribute associated with a cluster object.

client: A computer on which the remote procedure call (RPC) client is executing.

cluster: A group of computers that are able to dynamically assign resource tasks among nodes in a group.

cluster name: The computer name that is associated with a cluster, rather than with a single computer system.

Cluster Name Object (CNO): An Active Directory Domain Services (AD DS) named computer account that matches the cluster name (Cluster Name Object (CNO)) is automatically created for the failover cluster during setup.

cluster network: A distinct communication path between a set of nodes that typically represents a subnet in the underlying network infrastructure.

cluster network interface: An instance of a connection point on a cluster network that is associated with a specific node.

cluster object: An entity that can be accessed or managed via the ClusAPI Protocol. A cluster object is either a cluster, node, resource, group, cluster network, cluster network interface, or cluster registry key.

cluster registry: A hierarchical data store that has lightly typed elements and that is stored by and accessed through the cluster. The abstraction that is presented to clients is similar to that presented by the Windows registry.

cluster registry root key: The root key of the cluster registry. The root key is described in [MS-RRP] section 3.1.1.1.1.

cluster security descriptor: A security descriptor that is associated with the management of a cluster.

cluster state: A state that consists of all the non-volatile configuration data and volatile current status data that is maintained by the cluster and accessible to active nodes.

common property: A named element of a schema defined by the server and specific to a cluster object. A schema element has at least one value consisting of a type and a format. Each object instance maintains its own set of values, which is part of the object's nonvolatile configuration data. All cluster objects, with the exception of a cluster registry key, have common properties.

computer name: The DNS or NetBIOS name.

curly braced GUID string: The string representation of a 128-bit globally unique identifier (GUID) using the form {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}, where X denotes a hexadecimal digit. The string representation between the enclosing braces is the standard representation of a GUID as described in [RFC4122] section 3. Unlike a GUIDString, a curly braced GUID string includes enclosing braces.

disk number: An integer value that can be used to identify a device in the system device namespace. As specified in [MS-DMRP], the Windows implementation uses device names in the form \device\HarddiskNNN for hard disks. All Windows NT operating system namespace device paths are created under \device for Windows. The disk number is the NNN in the Windows NT namespace device path.

disk signature: A unique identifier for a disk. For a master boot record (MBR)-formatted disk, this identifier is a 4-byte value stored at the end of the MBR, which is located in sector 0 on the disk. For a GUID partitioning table (GPT)-formatted disk, this value is a GUID stored in the GPT disk header at the beginning of the disk.

Domain Name System (DNS): A hierarchical, distributed database that contains mappings of domain names to various types of data, such as IP addresses. DNS enables the location of computers and services by user-friendly names, and it also enables the discovery of other information stored in the database.

dynamic endpoint: A network-specific server address that is requested and assigned at run time. For more information, see [C706].

environment variable: A set of string name/value pairs that are used to abstract host-specific parameters, such as the location of the operating system or installed binaries.

failover cluster: A set of independent computers that work together to increase the availability of services and applications. The term cluster is sometimes used as shorthand for failover cluster.

fault domain: A set of hardware components that share a single point of failure.

file system flags: A set of values used by a file system to configure and report file system features and operations.

fully qualified domain name (FQDN): An unambiguous domain name that gives an absolute location in the Domain Name System's (DNS) hierarchy tree, as defined in [RFC1035] section 3.1 and [RFC2181] section 11.

globally unique identifier (GUID): A term used interchangeably with universally unique identifier (UUID) in Microsoft protocol technical documents (TDs). Interchanging the usage of these terms does not imply or require a specific algorithm or mechanism to generate the value. Specifically, the use of this term does not imply or require that the algorithms described in [RFC4122] or [C706] have to be used for generating the GUID. See also universally unique identifier (UUID).

group: A cluster group is a container for zero or more cluster resources, when referring to cluster groups. Groups enable resources to be combined into larger logical units and are owned by only one node in the cluster at a time.

group set: A cluster group set is a container for zero or more cluster groups. Group sets enable groups to be combined into larger logical units. The groups in a group set can be owned by different nodes in a cluster.

GUID partition table (GPT): A disk-partitioning scheme that is used by the Extensible Firmware Interface (EFI). GPT offers more advantages than master boot record (MBR) partitioning because it allows up to 128 partitions per disk, provides support for volumes up to 18 exabytes in size, allows primary and backup partition tables for redundancy, and supports unique disk and partition IDs through the use of globally unique identifiers (GUIDs). Disks with GPT schemes are referred to as GPT disks.

GUIDString: A GUID in the form of an ASCII or Unicode string, consisting of one group of 8 hexadecimal digits, followed by three groups of 4 hexadecimal digits each, followed by one group of 12 hexadecimal digits. It is the standard representation of a GUID, as described in [RFC4122] section 3. For example, "6B29FC40-CA47-1067-B31D-00DD010662DA". Unlike a curly braced GUID string, a GUIDString is not enclosed in braces.

Interface Definition Language (IDL): The International Standards Organization (ISO) standard language for specifying the interface for remote procedure calls. For more information, see [C706] section 4.

master boot record (MBR): Metadata such as the partition table, the disk signature, and the executable code for initiating the operating system boot process that is located on the first sector of a disk. Disks that have MBRs are referred to as MBR disks. GUID partitioning table (GPT) disks, instead, have unused dummy data in the first sector where the MBR would normally be.

MULTI_SZ: A character buffer for holding null-terminated strings, as specified in [MS-DTYP] section 2.8.

NetBIOS name: A 16-byte address that is used to identify a NetBIOS resource on the network. For more information, see [RFC1001] and [RFC1002].

network: A communications infrastructure over which two or more nodes in the cluster can communicate with one another. A cluster network represents a subnet on which a network interface is connected.

Network Data Representation (NDR): A specification that defines a mapping from Interface Definition Language (IDL) data types onto octet streams. NDR also refers to the runtime environment that implements the mapping facilities (for example, data provided to NDR). For more information, see [MS-RPCE] and [C706] section 14.

network interface: An interface on a cluster network that is connected to a node and is used to communicate with other nodes on the same network.

node: A computer system that is configured as a member of a cluster. That is, the computer has the necessary software installed and configured to participate in the cluster, and the cluster configuration includes this computer as a member.

notification port: An event creation mechanism, subscribed to by applications, that provides information about changes in the state and configuration of one or more objects in the cluster state.

NT file system (NTFS): A proprietary Microsoft file system. For more information, see [MSFT-NTFS].

opnum: An operation number or numeric identifier that is used to identify a specific remote procedure call (RPC) method or a method in an interface. For more information, see [C706] section 12.5.2.12 or [MS-RPCE].

partition: In the context of hard disks, a logical region of a hard disk. A hard disk can be subdivided into one or more partitions.

private property: A named element of a schema defined by and specific to a cluster object. A schema element has at least one value consisting of a type and a format. Not all objects define private schemas and an object can define the private schema for another object. If a schema is defined, each object instance maintains its own set of values, which are part of the object's nonvolatile configuration data.

protocol server state: A status that is local to a server and that indicates the server's ability to accept ClusAPI Protocol requests that operate on the cluster state.

registry: A local system-defined database in which applications and system components store and retrieve configuration data. It is a hierarchical data store with lightly typed elements that are logically stored in tree format. Applications use the registry API to retrieve, modify, or delete registry data. The data stored in the registry varies according to the version of the operating system.

remote procedure call (RPC): A communication protocol used primarily between client and server. The term has three definitions that are often used interchangeably: a runtime environment providing for communication facilities between computers (the RPC runtime); a set of request-and-response message exchanges between computers (the RPC exchange); and the single message from an RPC exchange (the RPC message).  For more information, see [C706].

resource: Any physical or logical component that can be managed by a cluster. A resource is owned by a single node at any one time.

resource class: A collection of resources that share a similar trait.

resource dependency: A relationship between two resources in which one resource cannot be online unless the other is online.

resource persistent state: A resource state to which the resource was most recently commanded to transition by a client.

resource private property: The part of a resource's nonvolatile configuration data whose schema is specific to the resource type.

resource type: A cluster resource type that uniquely categorizes cluster resources and codifies the functionality that is required for a node to own that resource in a cluster.

resource type private property: The part of a resource type's nonvolatile configuration data whose schema is specific to the resource type. The private properties of a resource type and its resources can be identical, can intersect, or can be mutually exclusive.

RPC context handle: A representation of state maintained between a remote procedure call (RPC) client and server. The state is maintained on the server on behalf of the client. An RPC context handle is created by the server and given to the client. The client passes the RPC context handle back to the server in method calls to assist in identifying the state. For more information, see [C706].

RPC protocol sequence: A character string that represents a valid combination of a remote procedure call (RPC) protocol, a network layer protocol, and a transport layer protocol, as described in [C706] and [MS-RPCE].

RPC transport: The underlying network services used by the remote procedure call (RPC) runtime for communications between network nodes. For more information, see [C706] section 2.

security descriptor: A data structure containing the security information associated with a securable object. A security descriptor identifies an object's owner by its security identifier (SID). If access control is configured for the object, its security descriptor contains a discretionary access control list (DACL) with SIDs for the security principals who are allowed or denied access. Applications use this structure to set and query an object's security status. The security descriptor is used to guard access to an object as well as to control which type of auditing takes place when the object is accessed. The security descriptor format is specified in [MS-DTYP] section 2.4.6; a string representation of security descriptors, called SDDL, is specified in [MS-DTYP] section 2.5.1.

security identifier (SID): An identifier for security principals that is used to identify an account or a group. Conceptually, the SID is composed of an account authority portion (typically a domain) and a smaller integer representing an identity relative to the account authority, termed the relative identifier (RID). The SID format is specified in [MS-DTYP] section 2.4.2; a string representation of SIDs is specified in [MS-DTYP] section 2.4.2 and [MS-AZOD] section 1.1.1.2.

security principal: An identity that can be used to regulate access to resources. A security principal can be a user, a computer, or a group that represents a set of users.

security provider: A pluggable security module that is specified by the protocol layer above the remote procedure call (RPC) layer, and will cause the RPC layer to use this module to secure messages in a communication session with the server. The security provider is sometimes referred to as an authentication service. For more information, see [C706] and [MS-RPCE].

server: A computer on which the remote procedure call (RPC) server is executing.

storage pool: A group of disks where all of the storage space on all of the disks is aggregated and managed as a single unit.

storage pool drive: A disk that is part of a storage pool.

subkey: A child node in the logical tree of the hierarchical data store.

top-level resource: A resource that no resource depends on.

Unicode: A character encoding standard developed by the Unicode Consortium that represents almost all of the written languages of the world. The Unicode standard [UNICODE5.0.0/2007] provides three forms (UTF-8, UTF-16, and UTF-32) and seven schemes (UTF-8, UTF-16, UTF-16 BE, UTF-16 LE, UTF-32, UTF-32 LE, and UTF-32 BE).

Unicode string: A Unicode 8-bit string is an ordered sequence of 8-bit units, a Unicode 16-bit string is an ordered sequence of 16-bit code units, and a Unicode 32-bit string is an ordered sequence of 32-bit code units. In some cases, it could be acceptable not to terminate with a terminating null character. Unless otherwise specified, all Unicode strings follow the UTF-16LE encoding scheme with no Byte Order Mark (BOM).

unique identifier (UID): A pair consisting of a GUID and a version sequence number to identify each resource uniquely. The UID is used to track the object for its entire lifetime through any number of times that the object is modified or renamed.

universally unique identifier (UUID): A 128-bit value. UUIDs can be used for multiple purposes, from tagging objects with an extremely short lifetime, to reliably identifying very persistent objects in cross-process communication such as client and server interfaces, manager entry-point vectors, and RPC objects. UUIDs are highly likely to be unique. UUIDs are also known as globally unique identifiers (GUIDs) and these terms are used interchangeably in the Microsoft protocol technical documents (TDs). Interchanging the usage of these terms does not imply or require a specific algorithm or mechanism to generate the UUID. Specifically, the use of this term does not imply or require that the algorithms described in [RFC4122] or [C706] has to be used for generating the UUID.

value: A data element associated with a key.

Virtual Computer Object (VCO): When a Cluster Name Object (CNO) clustered role is created or configured with a client access point, the cluster automatically creates a Virtual Computer Object (VCO).

volume: A group of one or more partitions that forms a logical region of storage and the basis for a file system. A volume is an area on a storage device that is managed by the file system as a discrete logical storage unit. A partition contains at least one volume, and a volume can exist on one or more partitions.

volume identifier (VolumeId): A 128-bit value used to represent a volume. The value of a VolumeId is unique on a single computer (the local file system or a remote file server).

MAY, SHOULD, MUST, SHOULD NOT, MUST NOT: These terms (in all caps) are used as defined in [RFC2119]. All statements of optional behavior use either MAY, SHOULD, or SHOULD NOT.