Technical Specification · VC-ENG-2200

Mycelial Data Fabric (MDF)

The facility data and comms backbone — a mycelium-inspired self-healing mesh that transports, time-aligns, stores, and secures every byte of telemetry between sensors, CHLORA, and actuation.

Doc ID: VC-ENG-2200 Rev: E · 2089-10-11 Owner: R. Okonkwo, Data Fabric & Platform Group Approver: Dr. H. Voss, Director Availability: 99.99% target Peak ingest: 7.8 Gb/s

1. Overview

The MDF is named for the mycelial networks it imitates: many redundant strands ("hyphae"), no single hub, and signaling that re-routes around damage. It carries the output of the PhytoSense Mesh and Spectral Canopy Array to CHLORA and delivers control packets back to actuators, all under deterministic latency guarantees.

Throughput (peak)7.8 Gb/s2.1M points/s

p95 Latency (intra)38 msSLA < 40 ms

Strand Links6123 link-disjoint paths min

Availability 30d99.993%▲ target met

2. Topology

Three logical planes over a partial-mesh physical fabric:

Edge plane — MDF gateways at zone boundaries aggregate sensor mesh traffic (802.15.4 / LoRa) onto the fabric.
Transport plane — redundant 25/100 GbE fiber strands in a partial mesh; every gateway has ≥ 3 link-disjoint paths to the core.
Core plane — two geographically separated core clusters (Sub-Level 2 / Sub-Level 4) running active-active; CHLORA and storage attach here.

No node is more than 4 transport hops from a core cluster. Design rule: survive any single core, any two strands, or any one gateway without SLA breach.

3. Protocols

Layer	Protocol	Purpose
Transport	QUIC over UDP, 0-RTT resumption	Low-latency streaming, head-of-line avoidance
Messaging	VC-Spore pub/sub (topic = zone/specimen)	Fan-out telemetry to CHLORA, dashboards, archive
Routing	Pheromone-weighted shortest-path (ant-colony inspired)	Self-healing, congestion-aware path selection
Encoding	CBOR + zstd	Compact, schema-evolvable telemetry
Time	PTP IEEE 1588v2 + hardware timestamping	Sub-µs alignment across the fabric

4. Throughput / Latency SLAs

Class	Example Traffic	Latency SLA (p95)	Loss	Priority
Control (CL0)	Containment interlock, actuator command	< 8 ms	0 (acked)	Strict-high, preemptive
Alarm (CL1)	CRITICAL/BREACH events	< 15 ms	0 (acked)	High
Telemetry (CL2)	PhytoSense / canopy streams	< 40 ms	< 1e-5	Assured
Bulk (CL3)	Radiance cubes, backups	< 2 s	best-effort	Scavenger

Preemption. CL0 control traffic preempts all lower classes on a congested strand. Bulk transfers are paused, not dropped, during any active CRITICAL/BREACH event.

5. Redundancy & Self-Healing Routing

Pheromone-weighted routing continuously probes path health; failed strands decay to zero weight within 250 ms and traffic reconverges on alternate disjoint paths.
Sub-50 ms failover for CL0/CL1 via pre-installed backup paths (no recompute on failure).
Active-active cores: loss of one core sheds zero traffic; sessions migrate via QUIC connection ID.
Gateway loss triggers sensor-mesh LoRa fallback to the nearest surviving gateway (see VC-ENG-2101 §7).

6. Time-Sync

A GPS/atomic-disciplined PTP grandmaster in each core provides the facility clock. Boundary clocks at every gateway hold member nodes to ±1 µs; measured fleet drift is ±0.9 µs. Accurate time is mandatory: CHLORA's anomaly detection and 2-of-3 sensor voting depend on aligned timestamps.

7. Storage Tiers

Tier	Medium	Window	Latency	Use
Hot	In-memory time-series ring	72 h	< 5 ms	Live dashboards, control loops
Warm	NVMe columnar store	90 days	< 50 ms	Trends, anomaly training windows
Cold	Erasure-coded object store	5 years	< 2 s	Index rollups, audit
Archive	Sealed cold object (immutable)	Indefinite	minutes	Regulatory, Universal Flora archive

8. Security & Encryption

In transit: TLS 1.3 / QUIC, mutual cert auth; every sensor packet additionally Ed25519-signed at the node.
At rest: AES-256-GCM, per-tier keys, 90-day rotation via the facility HSM.
Access: zero-trust, scoped API tokens; GCL-4 specimen streams require CBO-tier authorization to read.
Integrity: append-only audit log of every control-plane command, hash-chained.

9. API Surface

Clients query through the MDF gateway API (gRPC + REST). Example telemetry query and response:

POST /v3/telemetry/query
Authorization: Bearer <scoped-token>
Content-Type: application/json

{
  "select": ["stem_turgor_kpa", "chl_fluor_fvfm"],
  "where": { "zone": "GCL-4/VAULT-03",
             "specimen_cluster": "TX-RADICANS-W7" },
  "range": { "from": "2089-11-04T08:00:00Z",
             "to":   "2089-11-04T09:00:00Z" },
  "agg": "mean", "bucket": "5m"
}

200 OK
{
  "schema": "vc.mdf.queryresult/3",
  "series": [
    { "t": "2089-11-04T08:00:00Z",
      "stem_turgor_kpa": 414.2, "chl_fluor_fvfm": 0.823 },
    { "t": "2089-11-04T08:05:00Z",
      "stem_turgor_kpa": 412.6, "chl_fluor_fvfm": 0.821 }
  ],
  "buckets": 12, "served_from": "warm", "latency_ms": 31
}

10. Integration with CHLORA

CHLORA subscribes to VC-Spore topics for live streams and reads the warm tier for training windows. Its decisions return as CL0 control packets that the MDF prioritizes and delivers under the 8 ms control SLA. Decision provenance is written to the hash-chained audit log. Full reasoning behavior is specified in VC-ENG-2300; resulting alarms route per VC-ENG-2400.

→ PhytoSense Mesh → CHLORA → Botanical Metrics