Deployment Topology

:::info Source Sourced from services/progress-service/DEPLOYMENT_TOPOLOGY.md in the documentation repo. :::

1. Containers

Container	Purpose
progress-api	xAPI + internal REST
progress-ingest	High-throughput statement ingest pipeline
progress-projector	Attempt + completion projection from statements
progress-outbox-relay	NATS publisher
progress-partition-manager	pg_partman scheduled jobs (create + detach)

2. Scaling

Container	Min	Max	HPA
progress-api	5	50	CPU > 60% or req-rate > 500 rps
progress-ingest	5	100	queue depth > 1000
progress-projector	3	20	projection lag > 10s
progress-outbox-relay	3	8	outbox backlog > 5000

3. Resources

Container	CPU req/limit	Mem req/limit
progress-api	500m / 2000m	512Mi / 2Gi
progress-ingest	1000m / 4000m	1Gi / 4Gi
progress-projector	500m / 2000m	512Mi / 2Gi

4. Storage

• Postgres — primary + 2 replicas (read scale-out).
• Partitioning — monthly + tenant-hash.
• Cold archive — S3 Parquet after 180 days.
• WAL archive — continuous to S3 cross-region.

5. Caching

• Redis (per region) — xAPI query cache (tenant + filters hash, 60s TTL).
• pgbouncer transaction-mode pool.

6. CDN

• None (all endpoints authenticated, no public caching).

7. Edge Rules

• Rate limits at edge (per tenant + per user, §API_CONTRACTS §8).
• xAPI ingest from allowlisted 3rd-party LRSes require IP + API key.

8. Regional Deployment

• One cluster per residency region.
• Statements pinned to tenant homeRegion.
• Analytics firehose cross-region via Kafka MirrorMaker.

9. Service Mesh

• mTLS.
• Egress: analytics-service (firehose), certification-service (completion event), notification-service, enrollment-service.

10. Release Strategy

• Rolling for ingest/projector (stateless).
• Blue/green for API.
• Migrations applied pre-deploy; CI runs fwd+back.

11. DR

• RPO 5 min (WAL archive).
• RTO 90 min (restore + replay event log).
• Event log is source-of-truth; tables can be rebuilt.

12. Diagram

delivery/assessment ──▶ NATS ──▶ progress-ingest ──▶ Postgres (statements, attempts)
                                     │
                                     ▼
                           progress-projector (derive attempt outcomes + completions)
                                     │
                                     ▼
                              outbox → NATS ──▶ certification, assignment, analytics, notification

xAPI clients ──HTTPS──▶ progress-api ──▶ Postgres read replicas
                                    └─▶ Redis (query cache)