Imported from registry/relations/has-node.md at commit 76a4a0c89924.

IRI Link Relation: `has-node`

Relation URI: https://iri.science/rels/has-node
CURIE: iri:has-node
Status: Draft
Version: 1.0.0
Source representation type: urn:doe-iri:resource:compute:system
Source resource type: urn:doe-iri:resource:compute:system
Target representation type: urn:doe-iri:resource:compute:node
Target resource type: urn:doe-iri:resource:compute:node

This document defines the iri:has-node relationship used by the DOE-IRI compute resource model.

The canonical relation URI is https://iri.science/rels/has-node. With the canonical IRI CURIE template https://iri.science/rels/{rel}, iri:has-node expands to that URI. The relation URI identifies the link-relation semantics and is distinct from any target representation profile.

1. Relationship Metadata

Field	Definition
Relationship	`iri:has-node`
Relation URI	`https://iri.science/rels/has-node`
Semantic meaning	Indicates that the identified compute node participates in or is managed as part of the source compute system.
Source representation type	`urn:doe-iri:resource:compute:system`
Target representation type	`urn:doe-iri:resource:compute:node`
Cardinality	`0..*` targets from a compute-system resource.
Target stability	Static resource representation. The target identifies a compute-node resource whose identity is independent of current health, allocation, or availability.
Authorization affects visibility	Yes. The relationship or individual node targets MAY be omitted when the requester is not authorized to discover node-level topology.
Target classification	Resource
Relationship volatility	Relatively static topology/configuration. Changes when system membership or represented topology changes, not merely when the node’s operational condition changes.

2. Semantic Meaning

The iri:has-node relationship indicates that the source compute system contains, manages, or otherwise presents the identified compute node as part of the system’s represented topology.

The relationship separates system identity from node identity. System-level characteristics belong to the source compute-system resource, while node-specific characteristics belong to the target compute-node resource.

The relationship MUST NOT be interpreted as indicating that the node is currently available for workload execution.

3. Source and Target Representation

The relationship MUST originate from:

urn:doe-iri:resource:compute:system

and MUST target:

urn:doe-iri:resource:compute:node

The target is a Resource representation, not an operation entry point or relationship resource.

4. Cardinality

A compute system MAY expose zero, one, or multiple node resources:

Compute System  -- iri:has-node -->  Compute Node
      1                  0..*

The use of 0..* permits facilities to expose aggregate system information without exposing individual node topology.

This link-relation definition imposes no inverse-cardinality requirement.

5. Static and Dynamic Semantics

iri:has-node describes relatively stable compute topology. The relationship SHOULD remain present across ordinary operational state changes such as node allocation, maintenance, drain, failure, or temporary unavailability.

Current node health, workload activity, allocation condition, and availability are outside the semantics of this relation. When represented, they are governed by the applicable IRI API contract and Resource Definition Profile.

6. Authorization and Visibility

Authorization MAY affect visibility of node topology. A provider MAY expose a compute system while omitting individual iri:has-node targets for requesters that are not permitted to discover node-level infrastructure details.

The absence of visible node targets MUST NOT be interpreted as proof that the compute system contains no nodes.

7. HAL Representation

{
  "_links": {
    "iri:has-node": [
      {
        "href": "/api/v2/status/resources/node-001",
        "profile": "https://iri.science/profiles/resource-definition/compute/node"
      },
      {
        "href": "/api/v2/status/resources/node-002",
        "profile": "https://iri.science/profiles/resource-definition/compute/node"
      }
    ]
  }
}

DOE Integrated Research Infrastructure — Link Relation: has-node