Amazon ElastiCache Serverless

Definition

Amazon ElastiCache Serverless is a serverless deployment option for ElastiCache that removes node sizing and cluster planning. Capacity scales automatically based on throughput, memory pressure, and latency targets. ElastiCache Serverless supports Valkey, Redis OSS, and Memcached engines. Released in 2023 and broadly adopted in 2024–2026.

Capacity model

• ElastiCache Processing Units (ECPUs) — Per-second metered units for compute, network, and operations
• Data stored — Per-GB-hour pricing for memory
• Min capacity — Optional floor in ECPUs to keep latency steady under burst
• Multi-AZ — Built in by default

When to use ElastiCache Serverless

• Unpredictable or bursty traffic — News, gaming, e-commerce flash sales
• Dev / staging environments that idle most of the time
• Multi-tenant SaaS where per-tenant load varies wildly
• Teams that lack the bandwidth to manage cluster sizing

When not to use it

• Very high steady-state load — Provisioned with reservation pricing is cheaper
• Latency under 0.5 ms required — Provisioned with VPC tuning is faster
• Need OS-level access to nodes — Serverless abstracts away the node layer

Common mistakes

Mistake 1: Picking Serverless without baseline modeling. If load is steady, provisioned wins on cost. Run a 30-day side-by-side to compare.

Mistake 2: Forgetting the per-GB-hour memory floor. Even if you never read the cache, you pay for data sitting in memory. Set TTLs aggressively.

Mistake 3: Treating Serverless as a primary database. Use MemoryDB for durable in-memory storage.

Related AWS Services

• Amazon MemoryDB for Valkey — Durable in-memory alternative
• Amazon ElastiCache (provisioned) — Lower steady-state cost
• Amazon DynamoDB DAX — Cache layer dedicated to DynamoDB

Related FactualMinds Content

• AWS Serverless Architecture
• AWS Application Modernization