Failure Domains

QNSP is designed with isolated failure domains to contain blast radius.

Service Isolation

Each service can fail independently:

• Separate process/container
• Independent health checks
• Circuit breakers on dependencies

Service Ports & Health Endpoints

Service	Port	Health Endpoint
edge-gateway	8107	GET /health, GET /proxy/health
platform-api	8080	GET /proxy/platform/health, GET /edge/platform/health
auth-service	8081	GET /proxy/auth/health, GET /edge/auth/health
vault-service	8090	GET /proxy/vault/health, GET /edge/vault/health
kms-service	8095	GET /proxy/kms/health, GET /edge/kms/health
storage-service	8092	GET /proxy/storage/health, GET /edge/storage/health
audit-service	8103	GET /proxy/audit/health, GET /edge/audit/health

Failure Modes

Edge Gateway Failure

• Impact: All external traffic blocked
• Mitigation: Multi-instance deployment, health-based routing

Auth Service Failure

• Impact: No new tokens issued
• Mitigation: Cached token validation, graceful degradation

KMS Service Failure

• Impact: No new encrypt/decrypt operations
• Mitigation: Cached keys (TTL: 600s default), queue pending operations

Storage Service Failure

• Impact: No data read/write
• Mitigation: Retry with backoff, client-side caching

Graceful Degradation

Services implement:

• Timeouts on all external calls
• Circuit breakers (open after N failures)
• Fallback responses where safe
• Health endpoint for orchestrator