2.5.5 ElastiCache (Redis)

1. Cluster Configuration

• Start with a cache.t2.small or similar for dev/test.

• Scale up with read replicas/shards for high-volume environments.

2. Security

• Place the Redis cluster in a private subnet, accessible only by ECS tasks.

• If SSL is needed, configure in-transit encryption.

3. Use Cases

• Session Storage (if you go with session-based auth).

• Caching frequently accessed data (market feeds, user presence).

• Socket.io Pub/Sub for multi-instance broadcasting.