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

IRI Link Relation: `has-cpu`

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

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

The canonical relation URI is https://iri.science/rels/has-cpu. With the canonical IRI CURIE template https://iri.science/rels/{rel}, iri:has-cpu 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-cpu`
Relation URI	`https://iri.science/rels/has-cpu`
Semantic meaning	Indicates that the compute node contains, provides, or is associated with the identified CPU resource.
Source representation type	`urn:doe-iri:resource:compute:node`
Target representation type	`urn:doe-iri:resource:compute:cpu`
Cardinality	`0..*` targets from a compute-node resource.
Target stability	Static resource representation. The target identifies a CPU resource independent of current utilization, frequency, health, or allocation.
Authorization affects visibility	Yes. CPU-level topology MAY be omitted when the requester is not authorized to discover processor-level details.
Target classification	Resource
Relationship volatility	Relatively static hardware/topology relationship. Ordinary CPU operational changes do not change the relationship.

2. Semantic Meaning

The iri:has-cpu relationship identifies CPU resources associated with the source compute node.

CPU-specific characteristics such as processor architecture, core count, thread count, clock characteristics, vendor, and model belong to the target CPU resource rather than being embedded into the link relationship.

3. Source and Target Representation

The relationship MUST originate from:

urn:doe-iri:resource:compute:node

and MUST target:

urn:doe-iri:resource:compute:cpu

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

4. Cardinality

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

Compute Node  -- iri:has-cpu -->  CPU
     1                0..*

A facility MAY expose aggregate CPU counts on the node without exposing individual CPU resources, so zero visible CPU targets does not necessarily mean that the node has no processors.

5. Static and Dynamic Semantics

The relationship describes relatively stable processor topology. It SHOULD NOT change solely because CPU cores are allocated, idle, unavailable to a particular user, frequency-throttled, or otherwise affected by dynamic operational conditions.

Current utilization, frequency, health, temperature, allocation condition, or availability is outside the semantics of this relation. When represented, it is governed by the applicable IRI API contract and Resource Definition Profile.

6. Authorization and Visibility

Authorization MAY affect visibility of CPU-level topology. A provider MAY omit CPU targets while still exposing aggregate processor counts on the node resource.

Absence of visible CPU targets MUST NOT be interpreted as evidence that the node lacks CPUs.

7. HAL Representation

{
  "_links": {
    "iri:has-cpu": [
      {
        "href": "/api/v2/status/resources/node-001-cpu-0",
        "profile": "https://iri.science/profiles/resource-definition/compute/cpu"
      },
      {
        "href": "/api/v2/status/resources/node-001-cpu-1",
        "profile": "https://iri.science/profiles/resource-definition/compute/cpu"
      }
    ]
  }
}

DOE Integrated Research Infrastructure — Link Relation: has-cpu