Exam AWS Certified Developer - Associate DVA-C02 topic 1 question 316 discussion

Should be D. Source: https://aws.amazon.com/blogs/compute/introducing-maximum-concurrency-of-aws-lambda-functions-when-using-amazon-sqs-as-an-event-source/

Didn't like the wording. A - provisioned concurrency keeps 2 functions on warm standby for critical work. this is a minimum. question is asking about a maximum of 2. B - Batch of 2 is fine. latency could see this fall flat on it's face though. lambda invocations between function and SQS are limited to 2, not strictly between lambda and vendor API. C - event filtering is completely irrelevant here. D - Maximum is what the question is asking for. this will limit the amount of requests made to the vendor API. I would much prefer to set the reserved concurrency at the lambda level but this can be overridden at the SQS event source mapping level so I guess this is the best answer.

Sqs event source mapping

D is the correct answer.

going with D

Controlled Execution: Provisioned concurrency ensures that a minimum number of Lambda execution environments are always available. Setting it to two guarantees that only two Lambda function instances can process messages from the SQS queue concurrently. Independent of Message Batch Size: Even if the SQS event source mapping delivers a batch of messages exceeding two, the provisioned concurrency limits the number of Lambda invocations happening simultaneously.

configuring a maximum concurrency of two on the SQS event source mapping, is not a valid option. The concept of maximum concurrency is not directly applicable to SQS event source mappings. Concurrency in the context of Lambda functions and SQS is controlled by the batch size and the function's reserved concurrency settings.

Correct answer is D. The maximum concurrency setting on the Amazon SQS event source mapping for the Lambda function controls how many messages are sent to the Lambda function concurrently. By setting it to two, you ensure that only two messages are processed concurrently, preventing the Lambda function from overwhelming the third-party API with more than two concurrent requests.