Which invocation frequency makes Provisioned Concurrency cost‑effective for sporadic Lambda traffic?

Goal

Determine the break‑even invocation rate for a low‑traffic Lambda function where Provisioned Concurrency (PC) becomes cheaper than on‑demand execution, taking into account current pricing, cold‑start penalties, and ARM‑based Graviton2 cost reductions.

Constraints

• Invocations < 100 per day, highly irregular.
• Function memory 512 MB, Java 11 runtime.
• Cold‑start latency 50–500 ms.
• On‑demand pricing: $0.20 per 1 M requests + $0.00001667 per GB‑ms.
• PC pricing: $0.0000041667 per GB‑hour per instance + $0.20 per 1 M requests.
• Graviton2 reduces per‑ms cost by ~20% and cold‑start times by ~30 %.

Uncertainty

There is no official calculator that maps these numbers to a specific invocation frequency threshold, and SnapStart may alter the trade‑off but is not supported with PC.

Questions

1. At what daily invocation count does Provisioned Concurrency become cheaper than on‑demand for a 512 MB Java 11 function on Graviton2, given the current pricing and typical cold‑start latency?
2. Does enabling SnapStart for the same function shift this break‑even point, and if so, by how much?
3. Can AWS Compute Optimizer provide a reliable estimate of the break‑even invocation rate for sporadic traffic, or is manual benchmarking required?