Is Redis safe for NHS patient session data?

ElastiCache Redis for NHS patient sessions: (1) VPC private subnet (eu-west-2, no public internet access -- DTAC Domain 2 and Domain 3), (2) Redis AUTH token (password authentication -- Cyber Essentials A3 access control), (3) TLS in transit (Redis 7 in-transit encryption -- Cyber Essentials A1), (4) 15-minute session TTL (NHS Login sessions -- patient data not retained beyond session), (5) Redis cluster mode (Multi-AZ -- FCA PS21/3 IBS session availability, NHS DTAC continuity). ClickMasters NHS session store pattern: NHS Login JWT token stored in Redis (15-minute TTL), patient data never persisted to Redis (fetched fresh from PostgreSQL per request -- not cached). Redis is acceptable for NHS session tokens, not for patient health data (health data stays in PostgreSQL with RLS).

When should a UK project use DynamoDB instead of Redis?

DynamoDB for UK projects when: (1) high-throughput NoSQL (10M+ operations/day -- IoT telemetry, clickstream, gaming leaderboard), (2) serverless (Lambda + DynamoDB -- no connection pool management), (3) single-digit millisecond latency at any scale (DynamoDB auto-scaling), (4) audit log storage (DynamoDB TTL for log retention -- low-cost, high-volume write). DynamoDB is WRONG for: (1) NHS patient data (AWS DynamoDB is US-headquartered service -- data may not stay in eu-west-2 without explicit configuration -- DTAC Domain 2 review required), (2) complex queries (DynamoDB is key-value -- complex queries require Global Secondary Index design upfront), (3) ACID transactions across tables (DynamoDB transactions -- less flexible than PostgreSQL). ClickMasters DynamoDB: audit logs, IoT telemetry, non-patient event stores -- never NHS Article 9 health data without explicit DTAC review.

Redis Vs Memcached Vs Dynamodb Uk Caching 202

Redis vs Memcached vs DynamoDB -- UK Caching and NoSQL (2026)

Updated: June 20269 min read

UKGBPComparisonUK GDPRUK Law

Direct Answer

ElastiCache Redis is ClickMasters default for UK regulated caching: native data structures (pub/sub for real-time NHS notifications, sorted sets for leaderboards, streams for event processing), persistence for session caching under FCA PS21/3, and Redis Cluster for high-availability IBS caching. Memcached is right for simple key-value caching where Redis complexity is unnecessary. DynamoDB is right for high-throughput NoSQL workloads -- not for NHS patient data without careful DTAC review. Cache choice affects NHS DTAC Domain 2 data residency (patient data in cache), FCA PS21/3 session availability, and UK GDPR data minimisation (cache TTL policies).

Factor	ElastiCache Redis 7	ElastiCache Memcached	DynamoDB (eu-west-1/2)
NHS patient data cache (DTAC D2)	BEST -- VPC private, eu-west-2, Redis Auth, TLS	VPC private, eu-west-2, SASL auth	AWS managed, eu-west-1 -- DTAC review required
FCA session caching (IBS)	BEST -- persistence (AOF/RDB), cluster failover	No persistence -- data lost on restart	Not designed for session caching
UK GDPR cache TTL (data minimisation)	BEST -- per-key TTL, EXPIRE command	Per-key TTL available	TTL attribute -- good
Real-time NHS notifications (pub/sub)	BEST -- Redis Pub/Sub, Redis Streams	No pub/sub	DynamoDB Streams -- event-driven, not pub/sub
NHS FHIR search results cache	BEST -- JSONB-equivalent in Redis, hash data type	Simple string values only	Document storage -- good for FHIR
ClickMasters NHS session store	BEST -- Redis cluster, 15-min TTL, TLS in transit	Not used	Not used for session
FinTech rate limiting (API)	BEST -- Redis INCR + EXPIRE, atomic operations	INCR available -- less atomic control	Atomic conditional writes -- more complex
High-throughput NoSQL (millions/day)	Good -- but relational is preferred	Good -- simple key-value	BEST -- 10M+ operations/day serverless
ClickMasters default	NHS, FCA, GDS session + cache + real-time	Simple cache (non-regulated, non-session)	High-throughput non-relational non-patient data