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CSA Loom — the Microsoft Fabric experience for Azure tenants where Fabric isn't yet available: lakehouses, warehouses, notebooks, semantic models, Activator rules, Data Agents, across Commercial, GCC, GCC-High, and DoD IL5

Loom Activator Engine service

Per ADR fiab-0005 and Data Activator parity workload.

Purpose

Reflex / Data Activator parity service. Declarative rules over streaming + tabular events with stateful object tracking + diverse action surface.

Service shape

Aspect Value
Repo path apps/fiab-activator-engine/
Language C# .NET 10
Rule engine NRules (.NET production-grade Rete)
State store Azure Cache for Redis Premium
Schedule store Azure Cosmos DB
Action dispatcher Azure Functions (Premium EP1 in Gov; Flex Consumption in Commercial)
Container host Container Apps (Commercial / GCC); AKS workload (GCC-H / IL5)
Build PRP PRP-06

Components

                  ┌─────────────────────────────────────────────────┐
                  │  Loom Console "Activator" pane                  │
                  │   Visual rule designer + KQL backing store      │
                  │   CRUD via REST → Cosmos DB (rule definitions)  │
                  └────────────────────┬────────────────────────────┘
                                       │ deploys/syncs
                                       ▼
                  ┌─────────────────────────────────────────────────┐
                  │  Loom Activator Engine container                │
                  │                                                  │
                  │  - Rule Scheduler (cron orchestrator)           │
                  │  - KQL Query Runner (scheduled queries → ADX)   │
                  │  - NRules Evaluator (rule firing logic)         │
                  │  - State Manager (Redis client)                 │
                  │  - Dispatcher client (calls Function App)       │
                  └─────────────────────────────────────────────────┘
                                       │
                                       ▼
                  ┌─────────────────────────────────────────────────┐
                  │  Action Dispatcher Function App                 │
                  │   Teams / Email / Power Automate / Logic App /  │
                  │   Databricks Job / ADF Pipeline / UDF / Webhook │
                  └─────────────────────────────────────────────────┘

Capacity / cost model

  • Per-rule cost: minimal (KQL query + Redis state ops per cadence)
  • Container scale: 1 minimum (for cron); scale-out on rule count
  • Estimated cost per 100 active rules at 1-min cadence: ~$80/month in Commercial

Health endpoint

GET /health returns:

{
  "status": "healthy",
  "redis_connection": "ok",
  "cosmos_connection": "ok",
  "adx_connection": "ok",
  "rules_loaded": 47,
  "last_evaluation_age_seconds": 12
}

Operational SLAs

Metric Target
End-to-end latency (event → action) 5-30 s
Rule scheduler lag < 10 s
Action dispatch success rate > 99%
Redis state read latency p99 < 50 ms

Runbooks