Question

A developer supports a Lambda function that processes uploaded orders. During flash sales, customers report failed order submissions. In CloudWatch, the developer observes that the function's Throttles metric spikes to hundreds per minute while the Errors metric remains near zero, and the ConcurrentExecutions metric flatlines at a fixed value during the spikes. What is the most likely root cause of the failed submissions?

Accepted Answer

The function is hitting its concurrency limit and being throttled, so invocations are rejected before the handler runs.

Answer

The function code is throwing unhandled exceptions that cause each invocation to fail after processing begins.

Answer

The function is experiencing cold starts that cause each invocation to time out during initialization.

Answer

The function's IAM execution role is missing permissions, causing every invocation to be denied.