DVA-C02 Which Command Should the Administrator Use Practice Questions

Explanation: Lambda's performance scales with memory allocation: more memory also provides proportional CPU power. For CPU-bound tasks like pandas processing, increasing memory reduces execution time significantly. The function is not memory-constrained (only 80% used), but by increasing memory, the function gets more CPU, which speeds up the processing. The timeout is already at the maximum (15 minutes), so increasing it further is not possible. Using S3 Select would reduce the data read, but that requires code changes to use S3 Select API. Increasing the batch size of the S3 event notification is irrelevant; the function processes one file per invocation.

Explanation: Lambda cold starts occur when the function is invoked after being idle, requiring initialization of the runtime and dependencies. Provisioned concurrency keeps a specified number of execution environments initialized and ready to respond immediately, eliminating cold start latency for those environments. Increasing memory can improve CPU performance but does not eliminate the initialization overhead. Lambda layers and moving to DynamoDB do not directly address cold starts.

Explanation: Increasing the memory allocation for a Lambda function also increases its CPU allocation, which can significantly speed up processing. This may allow the function to complete within the existing timeout. While increasing the timeout may also help, adjusting memory first is more effective because it directly addresses the root cause (slow processing). Increasing concurrency does not affect a single invocation, and batch size is not applicable to S3 event triggers.

Explanation: Lambda functions in a VPC require security group rules to allow outbound traffic to the RDS database and inbound traffic from the Lambda function. If the security group of the RDS database does not allow inbound connections from the Lambda function's security group, the connection will time out. Since the database is in the same VPC, a NAT gateway is not needed for connectivity. DNS resolution works within the VPC.

Explanation: The function's timeout is 30 seconds, and synchronous HTTP calls can take variable time. By using asynchronous HTTP calls, the function can initiate multiple requests concurrently and wait for all responses, reducing the total wall clock time. This allows processing more messages within the timeout, maximizing throughput. Increasing the timeout is possible but does not address the underlying latency and may hide issues. Reducing the batch size reduces throughput. Changing the SQS visibility timeout does not affect the Lambda function's execution timeout.