# WIA-COMM-013 PHASE 2 — API Interface Specification **Standard:** WIA-COMM-013 **Phase:** 2 — API Interface **Version:** 1.0 **Status:** Stable **Source:** synthesized from the original `PHASE-1-DATA-FORMAT.md` (quarter 2 of 4) --- ## 4. Cooling Systems ### 4.1 PUE (Power Usage Effectiveness) **Definition:** ``` PUE = Total Facility Power / IT Equipment Power Example: Total Facility Power: 1200 kW IT Equipment Power: 1000 kW PUE = 1200 / 1000 = 1.2 ``` **Industry Benchmarks:** - **Legacy Data Centers**: PUE 1.8-2.0 - **Typical Enterprise**: PUE 1.5-1.7 - **Modern Efficient**: PUE 1.2-1.4 - **Hyperscale Best Practice**: PUE 1.1-1.15 - **Theoretical Minimum**: PUE 1.0 **Google Fleet Average (2024)**: PUE 1.10 **Facebook/Meta Average**: PUE 1.09 ### 4.2 Cooling Technologies #### 4.2.1 CRAC (Computer Room Air Conditioner) ``` Specifications: - Capacity: 10-30 tons (35-105 kW) - Technology: Direct expansion (DX) - Refrigerant: R410A, R134a, or eco-friendly - COP (Coefficient of Performance): 2.5-3.5 - Layout: Perimeter or in-row placement - Control: Thermostat or BMS integration Advantages: + Self-contained system + Easier installation + Lower upfront cost Disadvantages: - Lower efficiency than CRAH - Refrigerant leaks - Shorter lifespan ``` #### 4.2.2 CRAH (Computer Room Air Handler) ``` Specifications: - Capacity: 20-100 tons (70-350 kW) - Technology: Chilled water - Water temp: 7-12°C (45-54°F) - COP: 3.5-5.0 - Fan control: Variable speed (VFD) Advantages: + Higher efficiency + Centralized chiller plant + Better scalability Disadvantages: - Requires chilled water infrastructure - Higher upfront cost - More complex piping ``` #### 4.2.3 In-Row Cooling ``` Placement: Between server racks Capacity: 20-40 kW per unit Ideal for: High-density racks (10-30 kW) Benefits: + Localized cooling + Shorter airflow path + Better hot spot management + Supports higher rack densities ``` #### 4.2.4 Liquid Cooling **Direct-to-Chip (Cold Plate):** ``` Working Principle: - Liquid flows through cold plates on CPUs/GPUs - Heat transferred to liquid - Liquid cooled in heat exchanger - Recirculated Specifications: - Coolant: Water, glycol, or dielectric fluid - Temperature: 25-40°C - Rack density: 50-100 kW - PUE improvement: 1.05-1.15 Use Cases: - HPC (High-Performance Computing) - AI/ML training - GPU clusters ``` **Immersion Cooling:** ``` Types: 1. Single-phase: Servers submerged, fluid doesn't boil 2. Two-phase: Fluid boils, vapor condenses Specifications: - Dielectric fluid (non-conductive) - Rack density: 100-250 kW - PUE: <1.05 - No fans required Advantages: + Highest density + Ultra-low PUE + Reduced noise + Better reliability (no dust) Challenges: - High upfront cost - Maintenance complexity - Limited vendor support ``` ### 4.3 Airflow Management **Hot Aisle / Cold Aisle Configuration:** ``` Layout: ┌─────────┐ ┌─────────┐ ┌─────────┐ │ Rack │ │ Rack │ │ Rack │ │ ◄───── │ │ ◄───── │ │ ◄───── │ Cold Aisle └─────────┘ └─────────┘ └─────────┘ ▲ ▲ ▲ │ │ │ │ Hot Aisle (Contained) │ │ │ │ ▼ ▼ ▼ ┌─────────┐ ┌─────────┐ ┌─────────┐ │ ─────► │ │ ─────► │ │ ─────► │ │ Rack │ │ Rack │ │ Rack │ └─────────┘ └─────────┘ └─────────┘ Containment Options: 1. Cold Aisle Containment (CAC): Enclose cold aisle 2. Hot Aisle Containment (HAC): Enclose hot aisle (more efficient) 3. Chimney/Duct: Exhaust heat directly to return ``` **Best Practices:** - **Rack fronts** face cold aisle - **Blanking panels** fill empty rack spaces - **Cable management** avoid blocking airflow - **Floor tiles** perforate in cold aisle only (60% open area) - **Ceiling height** 10-12 feet minimum - **Raised floor** 24-36 inches for optimal airflow ### 4.4 Free Cooling (Economizers) **Air-Side Economizer:** ``` Use outside air when ambient < 15°C (59°F) PUE reduction: 0.1-0.3 Annual savings: 30-60% cooling energy ``` **Water-Side Economizer:** ``` Use cooling tower water directly Wet-bulb temp < 10°C (50°F) PUE reduction: 0.1-0.2 More reliable than air-side ``` --- ## 5. Network Architecture ### 5.1 Spine-Leaf Topology ``` Modern Standard Architecture: [Core/Spine Layer] ┌──────┬──────┬──────┐ │Spine1│Spine2│Spine3│ (40/100G uplinks) └──┬───┴───┬──┴───┬──┘ │ │ │ ┌────┴───────┴──────┴────┐ │ │ [Leaf/ToR Layer] [Leaf/ToR Layer] ┌─────┬─────┬─────┐ ┌─────┬─────┐ │Leaf1│Leaf2│Leaf3│ │Leaf4│Leaf5│ (10/25G downlinks) └──┬──┴──┬──┴──┬──┘ └──┬──┴──┬──┘ │ │ │ │ │ Racks Racks Racks Racks Racks Characteristics: ✓ Non-blocking bandwidth ✓ Predictable latency ✓ East-west traffic optimization ✓ Horizontal scalability ✓ No spanning tree required ``` ### 5.2 Network Equipment **Top-of-Rack (ToR) Switches:** - **Ports**: 48-64 × 10/25GbE downlinks - **Uplinks**: 4-8 × 40/100GbE to spine - **Redundancy**: Dual switches per rack (Tier III+) - **Protocols**: BGP, VXLAN, EVPN **Spine Switches:** - **Ports**: 32-64 × 40/100/400GbE - **Capacity**: 12.8-25.6 Tbps - **Redundancy**: N+1 or 2N configuration - **Buffers**: Deep buffers for incast **Core Routers:** - **Capacity**: 100+ Tbps - **Uplinks**: Multiple 100/400GbE WAN - **Redundancy**: Geographic diversity - **Features**: DDoS protection, traffic shaping ### 5.3 Cabling Standards | Type | Use Case | Distance | Bandwidth | |------|----------|----------|-----------| | Cat6A | Server to ToR | 100m | 10GbE | | Cat8 | High-density ToR | 30m | 25/40GbE | | Single-Mode Fiber | Rack to spine | 10km+ | 100GbE+ | | Multi-Mode Fiber (OM4) | Rack to spine | 550m | 100GbE | | DAC (Direct Attach Copper) | In-rack | 7m | 100GbE | ### 5.4 Software-Defined Networking (SDN) **Components:** - **Controller**: Centralized network management (OpenFlow, NETCONF) - **Orchestration**: Automated provisioning - **Telemetry**: Real-time monitoring - **Automation**: Intent-based networking **Benefits:** - Faster deployment - Network virtualization - Improved troubleshooting - Better resource utilization --- ## 6. Rack Design and Layout ### 6.1 Standard Rack Specifications ``` Standard 19-inch Rack: - Height: 42U-48U - Width: 19 inches (482.6 mm) - Depth: 36-48 inches (914-1219 mm) - Weight capacity: 1000-3000 lbs (450-1360 kg) - Power: 2-4 PDUs per rack ``` ### 6.2 Rack Density Classifications | Density Class | Power per Rack | Typical Workload | |---------------|----------------|------------------| | Low | 2-5 kW | Storage, networking | | Medium | 5-10 kW | General servers | | High | 10-20 kW | Virtualization, database | | Very High | 20-30 kW | GPU, HPC | | Ultra-High | 30-100 kW | AI/ML, liquid-cooled | ### 6.3 Floor Layout Planning **Capacity Calculation:** ``` Total Raised Floor Area: 10,000 sq ft Racks: 40 (arranged in 5 rows × 8 racks) Rack footprint: 2 ft × 4 ft = 8 sq ft Aisle width: 4 ft (cold), 5 ft (hot) Support space: 30% (power, cooling, walkways) Usable area = 10,000 × 0.7 = 7,000 sq ft Rack area = 40 × 8 = 320 sq ft Utilization = 320 / 7,000 = 4.6% ``` **Best Practices:** - **Cold aisle width**: 3-4 feet - **Hot aisle width**: 4-5 feet - **Equipment spacing**: 6-inch clearance - **Emergency exits**: <200 feet from any point - **Loading dock**: Direct access to data hall --- ## Annex E — Implementation Notes for PHASE-2-API-INTERFACE The following implementation notes document field experience from pilot deployments and are non-normative. They are republished here so that early adopters can read them in context with the rest of PHASE-2-API-INTERFACE. - **Operational scope** — implementations SHOULD declare their operational scope (single-tenant, multi-tenant, federated) in the OpenAPI document so that downstream auditors can score the deployment against the correct conformance tier in Annex A. - **Schema evolution** — additive changes (new optional fields, new error codes) are non-breaking; renaming or removing fields, even in error payloads, MUST trigger a minor version bump. - **Audit retention** — a 7-year retention window is sufficient to satisfy ISO/IEC 17065:2012 audit expectations in most jurisdictions; some regulators require longer retention, in which case the deployment policy MUST extend the retention window rather than relying on this PHASE's defaults. - **Time synchronization** — sub-second deadlines depend on synchronized clocks. NTPv4 with stratum-2 servers is sufficient for most deadlines expressed in this PHASE; PTP is recommended for sites that require deterministic interlocks. - **Error budget reporting** — implementations SHOULD publish a monthly error-budget summary (latency p95, error rate, violation hours) in the format defined by the WIA reporting profile to facilitate cross-vendor comparison without exposing tenant-specific data. These notes are not requirements; they are a reference for field teams mapping their existing operations onto WIA conformance. ## Annex F — Adoption Roadmap The adoption roadmap for this PHASE document is non-normative and is intended to set expectations for early implementers about the relative stability of each section. - **Stable** (sections marked normative with `MUST` / `MUST NOT`) — semantic versioning applies; breaking changes require a major version bump and at minimum 90 days of overlap with the prior major version on all WIA-published reference implementations. - **Provisional** (sections in this Annex and Annex D) — items are tracked openly and may be promoted to normative status without a major version bump if community feedback supports promotion. - **Reference** (test vectors, simulator behaviour, the reference TypeScript SDK) — versioned independently of this document so that mistakes in reference material can be corrected without amending the published PHASE document. Implementers SHOULD subscribe to the WIA Standards GitHub release notifications to track promotions between these tiers. Comments on the roadmap are accepted via the GitHub issues tracker on the WIA-Official organization. The roadmap is reviewed at every minor version of this PHASE document, and the review outcomes are recorded in the version-history table at the start of the document. ## Annex G — Test Vectors and Conformance Evidence This annex describes how implementations capture and publish conformance evidence for PHASE-2-API-INTERFACE. The procedure is non-normative; it standardizes the shape of evidence so that auditors and downstream integrators can compare implementations without re-running the full test matrix. - **Test vectors** — every normative requirement in this PHASE has at least one positive vector and one negative vector under `tests/phase-vectors/phase-2-api-interface/`. Implementations claiming conformance MUST run all vectors in CI and publish the resulting pass/fail matrix in their compliance package. - **Evidence package** — the compliance package is a tarball containing the SBOM (CycloneDX 1.5 or SPDX 2.3), the OpenAPI document, the test vector matrix, and a signed manifest. Signatures use Sigstore (DSSE envelope, Rekor transparency log entry) so that downstream consumers can verify provenance without trusting a private CA. - **Quarterly recheck** — implementations re-publish the evidence package every quarter even if no source change occurred, so that consumers can detect environmental drift (compiler updates, dependency updates, OS updates) without polling vendor changelogs. - **Cross-vendor crosswalk** — the WIA Standards working group maintains a crosswalk that maps each vector to the equivalent assertion in adjacent industry programs (where one exists), so an implementer that already certifies under one program can show conformance to PHASE-2-API-INTERFACE with reduced incremental effort. - **Negative-result reporting** — vendors MUST report negative results with the same fidelity as positive ones. A test that is skipped without recorded justification is treated by auditors as a failure. These conventions are intended to make conformance evidence portable and machine-readable so that adoption of PHASE-2-API-INTERFACE does not require bespoke auditor tooling. ## Annex H — Versioning and Deprecation Policy This annex codifies the versioning and deprecation policy for PHASE-2-API-INTERFACE. It is non-normative; the rules below describe the policy that the WIA Standards working group commits to when amending this PHASE document. - **Semantic versioning** — major / minor / patch components follow Semantic Versioning 2.0.0 (https://semver.org/spec/v2.0.0.html). Major bump indicates a backwards-incompatible change to a normative requirement; minor bump indicates new normative requirements that do not break existing implementations; patch bump indicates editorial changes only (clarifications, typo fixes, formatting). - **Deprecation window** — when a normative requirement is removed or altered in a backwards-incompatible way, the prior major version is maintained in parallel for at least 180 days. During the parallel window, both major versions are marked Stable in the WIA Standards registry and either may be cited as "WIA-conformant". - **Sunset notification** — deprecated major versions enter a 12-month sunset window during which the WIA registry marks the version as Deprecated. The deprecation entry includes a migration note pointing to the replacement requirement(s) and an explanation of why the change was made. - **Editorial errata** — patch-level errata are issued without a deprecation window because they do not change normative behaviour. Errata are tracked in a public errata register and each entry is signed by the WIA Standards working group chair. - **Implementation changelog mapping** — implementations SHOULD publish a changelog mapping each PHASE version they support to the specific build, container digest, or SDK version that satisfies the version. This allows downstream auditors to verify version conformance without re-running the entire test matrix on every release. The policy is reviewed at the same cadence as the PHASE document and any changes to the policy itself are tracked in the version-history table at the start of the document. ## Annex I — Interoperability Profiles This annex describes how implementations declare interoperability profiles for PHASE-2-API-INTERFACE. The profile mechanism is non-normative and exists so that deployments of varying scope (single tenant, regional cluster, federated network) can advertise the subset of normative requirements they satisfy without misrepresenting partial conformance as full conformance. - **Profile manifest** — every implementation publishes a profile manifest in JSON. The manifest enumerates the normative requirement IDs from this PHASE that are satisfied (`status: "supported"`), partially satisfied (`status: "partial"`, with a reason field), or excluded (`status: "excluded"`, with a justification). The manifest is signed using the same Sigstore key used for the SBOM in Annex G. - **Federation profile** — federated deployments publish an aggregated manifest summarizing the union and intersection of member-implementation profiles. The aggregated manifest is consumed by directory services so that callers can route a request to the least common denominator profile required for an interaction. - **Backwards-profile compatibility** — when a deployment migrates from one profile to a wider profile, the prior profile manifest remains valid and signed for the deprecation window defined in Annex H. This preserves audit traceability for auditors evaluating long-term interoperability. - **Profile registry** — the WIA Standards working group maintains a public registry of named profiles. Common deployment shapes (e.g., "Edge-only", "Federated-with-replay") are added to the registry by consensus. Registry entries are immutable; new shapes are added under new names rather than amending existing entries. - **Profile versioning** — profile names are versioned with the same Semantic Versioning rules described in Annex H. A deployment that advertises `WIA-P2-API-INTERFACE-Edge-only/2` is asserting conformance with the second major version of the named profile, not the second deployment of an unversioned profile. The profile mechanism is intentionally lightweight; it is meant to make real deployment shapes visible without forcing every deployment to satisfy every normative requirement. ## Annex J — Reference Implementation Topology The reference implementation topology described in this annex is non-normative; it documents the deployment shape that the WIA Standards working group used to validate the test vectors in Annex G and is intended as a starting point, not a recommendation against alternative topologies. - **Single-tenant edge** — one runtime per organization, no shared state. Used for early-pilot deployments where conformance evidence is published manually. Sufficient for PHASE-2-API-INTERFACE validation when the organization signs the manifest itself. - **Multi-tenant gateway** — one shared runtime serves multiple tenants via header-based isolation. Typically backed by a rate-limited gateway (Envoy or NGINX) and a shared OAuth 2.1 identity provider. The manifest is per-tenant; the runtime publishes a federation manifest that aggregates tenant manifests. - **Federated mesh** — multiple runtimes peer to one another and publish their manifests to a directory service. Each peer signs its own manifest; the directory service signs the aggregated index. This is the topology used by cross-organization deployments that need to compose conformance. - **Air-gapped batch** — no network connection between the runtime and the directory service. The runtime emits a signed evidence package on each batch and the operator transports the package via out-of-band channels. This is the topology used by regulators that prohibit live connectivity from sensitive environments. Implementations declare their topology in the manifest (see Annex I). A topology change MUST be reflected in a new manifest signature; the prior topology's manifest remains valid for the deprecation window described in Annex H to preserve audit traceability.