You create a Lambda Function to process clients’ queries from a web application. The workload is time sensitive so that you want the Lambda function to finish processing and respond as quickly as possible. You prefer allocating more resources such as memories or CPUs to the Lambda Function. However, you are unsure how many resources are being used at the moment. Which action can help you to get the current memory usage and allocate more resources if needed?

Answer options:

A.Check the default CloudWatch metrics to get the allocated and used memories. Pre-allocate more resources to the Lambda Function if required.
B.Check CloudWatch Logs to get the max memory used and allocate more memory if needed.
C. Check CloudWatch metrics to get the max number of invocations. Increase the reserved concurrency to speed up the processing time.
D.Memories and CPUs in Lambda Function are managed by AWS and can auto-scale if required. You are not supposed to allocate more resources by yourself.

Correct Answer – B
Check https://docs.aws.amazon.com/lambda/latest/dg/resource-model.html on how to configure Lambda Functions. Users can allocate memories for a Lambda Function as below:
Option A is incorrect: We cannot use the default CloudWatch metrics to get the allocated and used memory.
Option B is CORRECT: We can get the max memory used from the CloudWatch logs.
If the max memory used is close to the memory allocated, it is better to allocate more memories to speed up the processing.
Option C is incorrect: Because the reserved concurrency does not influence how many memories or CPUs the Lambda Function has to process a request.
Option D is incorrect: Although Lambda Function is serverless, users are still responsible for monitoring the running status and allocating more resources if needed.