flowchart TB Req["Gateway receives request with bearer token"]:::start Check["Check ElastiCache Redis for cached district mapping"]:::start A1["A: Redis reachable, fresh
within 60s TTL"]:::healthy A2["Return cached district_id"]:::healthy B1["B: Redis reachable, expired
Cache TTL Expiry passed"]:::healthy B2["Re-fetch mapping from identity service"]:::healthy B3["Re-populate Redis with a fresh 60s TTL"]:::healthy C1["C: Redis unreachable"]:::fallback C2["Fall back to the pod's local LRU Fallback Cache"]:::fallback C3["Serve from local cache, else re-fetch from identity service directly"]:::fallback End["Proceed to Tier-1 validation
ingestion never blocks on cache health"]:::start Req --> Check Check --> A1 --> A2 --> End Check --> B1 --> B2 --> B3 --> End Check --> C1 --> C2 --> C3 --> End classDef start fill:#37474f,stroke:#1c2529,color:#fff,font-size:13px classDef healthy fill:#2a9d8f,stroke:#1f7a6f,color:#fff,font-size:13px classDef fallback fill:#e9a23b,stroke:#b8791f,color:#222,font-size:13px linkStyle default stroke:#999,stroke-width:2px