Atlas now provisions a private ElastiCache Valkey cache

Atlas now has a Terraform-managed ElastiCache Valkey layer for backend workloads.

This rollout adds:

• a reusable elasticache-valkey Terraform module
• a dedicated private subnet group for the cache
• a dedicated security group that allows 6379 only from the approved ECS workload security groups
• a Valkey replication group with cluster mode disabled, one primary, one replica, Multi-AZ failover, and IPv4 connectivity
• root outputs for the primary endpoint, reader endpoint, port, subnet group, and security group

The initial configuration intentionally keeps at-rest encryption disabled, in-transit encryption disabled, backup retention at one day, and automatic minor version upgrades turned off to match the requested rollout posture.

In committed values, production uses the requested names atlas-redis and atlas-elasticache-private. Staging uses -dev suffixes so both roots can coexist safely even if they target the same AWS account and region.