Relationships

Node associations are represented by relationships. There are different types of relationships which define hierarchy, hosting, containment, ownership, manufacturer, category, versions, location, dependency, in fact, any kind of relationship required to model an IT infrastructure.
A type of relationship is represented as colon-separated strings. A relationship comprises more than the two node endpoints, it contains the "route" between the two. This is made up in the following way:

Node:Role:RelationshipLink:Role:Node

For example, the relationship from a Host node to the Cluster node that contains the host is shown as:

Host:ContainedHost:HostContainment:HostContainer:Cluster

The relationship from a Cluster node to a Host node that it contains is shown as:

Cluster:HostContainer:HostContainment:ContainedHost:Host

Note

A relationship is a bidirectional link between two nodes. In this section, the terms "start node" and "target node" are used to describe the way that the relationship is built. However, once the relationship has been built, the terms are redundant.

The general timeline for the creation of a relationship is:

Create "start node".
Create "target node".
Create relationship between 1 and 2.

The individual components of the relationship are described in the following sections.

Node

The node is any kind of node that can have a relationship, such as a Host node. All nodes can have relationships, including relationships.

Relationship kinds

The relationship kind describes the nature of the relationship. For example, the DeviceSubnet relationship kind describes the link between a device and the subnet that it is on, but without any directionality implied.

Note

This section refers to Relationship Kinds as the colon-separated lists which describe how two nodes are related, the roles that each node plays in the relationship, and the Relationship Link which describes the nature of the Relationship.

A complete list of Relationship Kinds with their descriptions is provided in the table below.

Relationship Kind	Description
Hierarchy Relationships
Hierarchy	Relates nodes into a hierarchy.
Attachment Relationships
Attachment	Relates a node to a file attachment.
Category Relationships
ElementCategory	Relates an element to a category it is in.
People Relationships
Ownership	Relates an element to its owner.
Management	Relates an employee to their manager.
Locations
Location	Relates an element to the location it is in.
LocationContainment	Relates a location to the larger location it is in.
Hosts
HostedSoftware	Relates software to the host it is running on.
HostContainment	Relates hosts and software instances to contained virtual hosts.
EndpointIdentity	Relates Hosts that appear to have changed identity
HostedService	Relates a service to the host it is running on
Applications
Activity	Relates a Model Definition to an activity that has been performed on it
Communication	Relates software instances to communicating software instances. Used when a pattern can identify configuration within a piece of software that specifies communication with another piece of software. For example, a pattern might be able to read a configuration file for an application server and see the address of a database server.
Dependency	Relates elements to elements they depend upon.
SoftwareContainment	Relates an item of software to an item contained in it.
SoftwareService	Relates an item of software to a service.
DefinitionClone	Relates a Model Definition to a cloned version of it
DefinitionContainment	Relates a Model Definition to items included or excluded by it
FunctionalContainment	Relates a Functional Component to an item contained within it
MultiFacet	Relates multiple facets of a single process
ObservedCommunication	Relates observed communicating elements. Used when communication between two pieces of software has been generically discovered from information like open network connections and listening ports. When Discovery is able to identify both ends of a communication, it tries to then correlate this information with software that it sees running. For this to work well, often root/administrator access for Discovery is needed, as operating systems only give all the pertinent information to sufficiently privileged users.
Physical Model
AdapterWithPort	Relates an adapter to a port
DeviceSubnet	Relates an IP device to the subnet it is on.
DeviceInterface	Relates an IP device with one of its network interfaces.
DeviceAddress	Relates an IP device with one of its IP addresses
NetworkLink	Relates a network interface on a host to a port interface on a switch.
HostedFile	Relates a file to its host.
RelatedFile	Relates a file to something that uses it.
FibreChannelNodeDevice	Relates a World Wide Node Number (WWNN) to an HBA.
FibreChannelNodePort	Relates a World Wide Port Number (WWPN) to a WWNN.
FileSystemMount	Relates the mounter and the FileSystem.
ChosenEndpoint	Relates a device successfully scanned by this endpoint
Endpoint	Relates a Discovery Access that successfully scanned a device by this endpoint
CloudService	Relates cloud services
CouplingFacility	Relates Coupling Facility to its dependents
ExportedFileSystem	Relates exported FileSystem to local FileSystem
ExposedView	Relates a port to an exposed view (volume)
HardwareUse	Relates hardware to the system using it
InterfaceAddress	Relates a network interface with its IP addresses
NetworkService	A network device service
Directly Discovered Data
DiscoveryAccessResult	Relates a DiscoveryAccess to one of its results.
List	Relates a List of Members.
Sequential	Relates sequential nodes.
Inference	Relates an inferred node with its source node.
Status	Relationship to a status node.
AccessFailure	Access failure.
AccessOptimization	Access optimization.
Metadata	Information about a discovery request.
DiscoveryCondition	Relates an element with a condition to that condition
EndpointRange	A range used to control endpoint access
ImplicitScan	Implicitly scanned IP address
Log	Relates a log to an item
Pattern Relationships
PatternModuleContainment	Associates a pattern module to its contents.
PatternModuleDependency	Associates a pattern module to its dependents.
Maintainer	Pattern that is maintaining an inferred node.
Requirement	Associates a pattern that will need the products of another.
Override	Associate patterns that are being overridden or are overriding others.
Deprecated	Associated pattern has been deprecated or is deprecating others.
Error	Errors generated by this pattern at runtime.
PatternExecution	Associates a PatternExecution to its Pattern.
PatternTouch	Associate a PatternTrigger with things it changed.
PatternTrigger	Associates a PatternExecution to its trigger nodes.
Request	Associates a Pattern to the DDD nodes requested by it.
IntegrationImplementation	Relates the implementation of a resource
ResourceUse	Relates the usage of a resource
CodeGeneration	Relates a generated pattern module to a pattern definition
UploadContents	Contents of unloaded knowledge
Generic Modeling Relationships
Containment	Relates an element to its container.
Detail	Relates an element to details about it.
SupportDetail	Relates Host and Software Instance nodes to SupportDetail nodes.
Collection	Relates an element to the collection in which it is contained
Mirror	Represents a mirroring relationship
Replacement	A node replaced during update
Replication	Represents a replication relationship
Rule Relationships
RuleModuleDependency	Associates a rule module to its dependents.
Foundation User Relationships
Favorite	A Favorite item for a User
InvokingUser	Relates to the invoking user
Hardware Reference Data Relationships
ReferenceData	Relates physical hosts to hardware reference data
HardwareReferenceData	Relates Host and HostContainer nodes to HardwareReferenceData nodes
Stack Devices
DeviceStack	Relates a stack member to the stack itself
Storage
SANStorage	Relates a host consumer of SAN storage to the reference to that host on the storage
Storage	Relates Storage to hosts using it
StorageContainment	Relates Storage to the Storage Collection containing it
StorageUse	Relates storage nodes

Role

The role describes the part that its node plays in the relationship.
For example, where a Host node represents a host which is running a software process:

A Software Instance has been created which represents the process running on the host.
The Host node is acting in the role of Host; the host for some running software.
The Software Instance is acting in the role of RunningSoftware; software which is running on a host.

Roles are required because a node can play one of many parts in a relationship, and clarification is needed; the role clarifies the part that the nodes are playing in the relationship.

A complete alphabetical list of Role Kinds in the default taxonomy with their descriptions is provided in the table below.

Role Kind	Description
ActedUpon	An item that is being acted on
ActivityRecord	An ActivityRecord
AggregateSoftware	Aggregate software running on a host
Associate	Associate inference
Attachment	Attachment
AttachmentContainer	Node containing an attachment
AutomaticGroup	A group automatically generated by BMC Discovery
BusinessOwner	Business owner of an element
Category	Category of elements
Child	Child in hierarchy
Client	Client
CloneForEdit	A Definition which is a clone of another for editing
CloneSource	A Definition which has been cloned
ClusteredSoftware	Clustered software running on a host
Collection	Element containing a collection of elements
Connecting	Connecting
Consumer	A consumer
Contained	An element contained within another
ContainedConnection	Contained connection
ContainedDrive	Contained disk drive
ContainedFunctionality	Component within a FunctionalComponent
ContainedHost	Host contained within another host
ContainedInstance	Contained load balancer instance
ContainedItem	An item within a container
ContainedLocation	A location inside another location
ContainedMember	Contained load balancer member
ContainedPool	Contained storage or load balancer pool
ContainedProcessor	Contained storage processor
ContainedService	Contained load balancer service
ContainedSoftware	Piece of software contained inside other software
ContainedStorage	Storage contained in an element
ContainedVolume	Contained storage volume
Container	An element containing others
Contributor	Contributor inference
Copy	Copy of item
CouplingFacility	Coupling Facility
Definition	Definition
Dependant	Entity that depends upon another
DependedUpon	Entity depended upon by another
Detail	A detail belonging to an element
Device	Device
DeviceOnSubnet	IP device belonging to a subnet
DeviceWithAddress	A device with an IP address
DeviceWithInterface	A device with an interface, for example, a network interface
DiscoveryAccess	Discovery access
DiscoveryCondition	Identifies a discovery condition
DiscoveryResult	Discovery result
DiscoveryRun	Discovery run
EdgeClient	Edge client
EdgeDevice	Edge device
Element	Element
ElementInCategory	Element belonging to a category
ElementInLocation	Element in a location
ElementUsingFile	Element using a file
ElementWithCondition	Identifies a node to which a discovery condition pertains
ElementWithDetail	Element with associated details
ElementWithStatus	Element with an associated status
Employee	Employee
Endpoint	Endpoint
EndpointRange	A range used to control endpoint access
Error	An ECAError related to a pattern
ExcludedItem	An item excluded from a Definition
ExplicitEndpoint	User provided endpoint
Exported	Exported filesystem
ExposedElement	Exposed element
Facet	Facet
Favorite	A favorite item for a user
FibreChannelDeviceWithNode	A Fibre Channel HBA with a WWNN
FibreChannelNode	A Fibre Channel WWNN for a HBA
FibreChannelNodeWithPort	A Fibre Channel WWNN with a WWPN
FibreChannelPort	A Fibre Channel WWPN
File	A File
FoundationUser	A BMC Discovery User
FrontEndPort	A Front End Port
FunctionalContainer	FunctionalComponent containing components
Hardware	Physical host to which hardware reference data will be related
HardwareDetail	Support Detail Data is for Hardware
HomeLocation	Home location of an element
Host	Host for Software Instances
HostContainer	Host containing other hosts
HostedFile	A File on a Host
IPv4Address	An IPv4 address
IPv6Address	An IPv6 address
ITOwner	IT owner of an element
ImplicitEndpoint	System provided endpoint
IncludedItem	An item included in a Definition
InferredElement	Inferred element
InferredRelationship	Inferred relationship
Input	Input data
InstalledSoftware	Installed software
IntegrationPoint	Integration point for a connection or query
InterfaceOfDevice	Interface of an IP device
InterfaceOfStack	Interface of the Stack
InterfaceWithAddress	Interface with an IP address
ItemWithLog	Item with log
List	List
Listening	Listening
Local	Local filesystem
Location	Current location of an element
LocationContainer	A location containing other locations
Log	Log
MainFacet	Main Facet
ManagedElement	Element being managed
Manager	Manager
ManufacturedItem	Manufactured item
Manufacturer	Manufacturer of an item
Member	Member of a list or collection
MountedFileSystem	Mounted file system
Mounter	Mounter of a file system
NetworkDevice	Network device
NetworkEndpoint	One end of a network connection
NetworkService	Network device providing a service
New	A new node
Next	Next node in sequence
OSDetail	Support Detail Data is for Operating System
Old	A replaced node
OperatingSystem	Operating system of a host
Original	Original item
Output	Output data
Overridden	A pattern that is overridden by another
Overrider	A pattern that is overriding another
OwnedItem	Item owned by someone or something
Owner	Owner of an item
Parent	Parent in hierarchy
Pattern	Pattern
PatternConfiguration	Pattern configuration
PatternConfirmed	Confirmed node
PatternCreated	Created node
PatternDefine	Pattern definitions function
PatternDefinitions	Pattern definitions
PatternDestroyed	Destroyed node
PatternExecution	Pattern execution
PatternModified	Modified node
PatternModule	Pattern module
PatternTrigger	Pattern trigger
PatternWithError	A pattern with ECAErrors
Peer	Peer
Previous	Previous node in sequence
Primary	Primary inference
Producer	A producer
Provider	A provider
ReferenceData	Holds hardware reference data
Region	Cloud Region in which the related resource resides
Relationship	Relationship
RequestSource	Source of discovery request
Resource	Resource being used
ResourceUser	User of resource
RunningService	Service running on a host
RunningSoftware	Software running on a host
Server	Server
Service	Service being provided
ServiceHost	Host providing a service
ServiceProvider	Provider of a service
SoftwareContainer	Piece of software containing other software
SoftwareDetail	Support Detail Data is for Software
Stack	Stack of Network Devices
StackMember	Network Device in Stack
Status	Status
Storage	Storage for an element
StorageContainer	Element containing storage
Subnet	Subnet of an IP device
SupportOwner	Person or group responsible for supporting an element
Upload	Uploaded knowledge
UploadItem	Component of uploaded knowledge

Provenance

By linking data items and their attributes to the evidence for them, BMC Discovery enables its data to be easily verified; a prerequisite for trusting it. This feature is called Provenance.
Provenance Data is created by the Reasoning Engine and consists of relationships between Directly Discovered Data items and entities inferred from them - a relationship back to the source from the inferred entity. For example, there is a provenance relationship between each Software Instance (SI) and the data that caused the SI to be inferred - typically one or more processes, files, or the like.

Provenance information is meta-information describing how the other information came to exist. It is generated as Reasoning builds and maintains the model. Provenance information is stored on relationships in the model.

Inference Types
- Primary — indicate that the existence of the evidence node is the reason that the inferred node was created.
- Contributor — indicate that the evidence node provided information used in building the inferred node.
- Associate — indicate that BMC Discovery knows there is a relationship between the evidence node and the inferred node.
- Relationship — indicate that BMC Discovery knows that a relationship exists because of the evidence node.
- Deletion — indicate that the removal of the inferred node was due to withdrawal of the evidence node.
Maintaining Pattern — the pattern maintaining a node.

If you need to access the data in your model you should access the UI functions provided in BMC Discovery that enable this. Apart from specialist purposes, you should not need to understand the provenance implementation details in BMC Discovery. However, an overview is provided below.

Note

For patterns as well as the overall functioning in BMC Discovery, if the system scans the infrastructure and captures some data but in a subsequent scan fails to obtain the same data, it does not immediately remove the old data. For example, a scan in the past may have captured a host and its installed packages. But the latest scan may fail to retrieve the packages. This does not mean that the host now has no installed packages. The system records the failure in DDD and leaves the existing data as the best-known information. In a subsequent scan if the system successfully gets a list of packages, and some packages that were previously present are now absent, then the system updates the data by removing the relationships to non-existing packages.

Provenance implementation details

To represent provenance information, attributes can be stored on the Inference relationships. The keys attribute contains a list of the attribute keys that were set or confirmed on the inferred node as a result of the inference. The rule attribute contains the name of the reasoning rule that decided upon the inference. Provenance information is only created and is not updated.

Inferred nodes are related to DDD nodes using 'Creation Inference' relationships. The Inferred node has the role InferredElement; the DDD node has the role Primary, Contributor or Associate as appropriate. To support the full lifecycle of inferred nodes there are complimentary Removal Inference relationships. Destruction is the complimentary role to Primary, and Withdrawal is the complimentary role to Contributor.

The method of linking of discovered information to inferred information means that in general, each inferred node will have relationships to many discovery data nodes, representing multiple discoveries of the entity over time.

The Reasoning Engine maintains this provenance information and this can be accessed using functions in the BMC Discovery Search Service named Provenance and Provenance Details.

Relationships between relationships

Relationships are technically a sub-class of nodes and they have the same basic characteristics. Relationships can have attributes stored in them and can have relationships to other nodes in the same way that nodes can.

A relationship connects two nodes between their role, however a relationship can also act in a role in a relationship. Therefore, you can have relationships between nodes and relationships or relationships between relationships.

Relationships between inferred nodes

Using patterns, the reasoning engine can construct a number of relationships between inferred nodes, as follows:

Links an SI to the Host it is running on.

SoftwareInstance:HostedSoftware:HostedSoftware:Host:Host

A client-server relationship between SIs. This can be inferred based on the presence of network connections between processes. It can also be based on other evidence such as configuration files or directly querying the endpoints.

SoftwareInstance:Client:Communication:Server:SoftwareInstance

Equivalent to the client-server case, but where the endpoints in a communication are peers, rather than client and server.

SoftwareInstance:Peer:Communication:Peer:SoftwareInstance

A dependency between SIs, other than a communication link. Attributes on the relationship can indicate the kind of dependency.

SoftwareInstance:Dependant:Dependency:DependedUpon:SoftwareInstance

Represents SIs that logically contain other SIs.

SoftwareInstance:SoftwareContainer:SoftwareContainment:ContainedSoftware:SoftwareInstance

Links a virtual host to the Software Instance that implements it.

SoftwareInstance:HostContainer:HostContainment:ContainedHost:Host

Links a configuration file to a Software Instance.

SoftwareInstance:ElementUsingFile:FileUse:ConfigurationFile:File

Represents the SIs that make up a BAI.

BusinessApplicationInstance:SoftwareContainer:SoftwareContainment:ContainedSoftware:SoftwareInstance

Represents BAIs that logically contain other BAIs.

BusinessApplicationInstance:SoftwareContainer:SoftwareContainment:ContainedSoftware:BusinessApplicationInstance

A dependency between BAIs.

BusinessApplicationInstance:Dependant:Dependency:DependedUpon:BusinessApplicationInstance

Indicates the Hosts which form a cluster.

Cluster:HostContainer:HostContainment:ContainedHost:Host

Indicates the SIs that provide clustering services for a cluster.

Cluster:Service:SoftwareService:ServiceProvider:SoftwareInstance

Represents the relationship between logical hosts and their container for Sun E15Ks and similar.

HostContainer:HostContainer:HostContainment:ContainedHost:Host

Represents the relationship between network interfaces and the subnets they are connected to.

Subnet:Subnet:DeviceSubnet:DeviceOnSubnet:NetworkInterface

In addition to these relationships, the reasoning engine also constructs relationships to the Pattern Management nodes, for example, patterns.

Relationships

Node

Relationship kinds

Role

Provenance

Provenance implementation details

Relationships between relationships

Relationships between inferred nodes

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