DVA-C02 · Question #261
An online sales company is developing a serverless application that runs on AWS. The application uses an AWS Lambda function that calculates order success rates and stores the data in an Amazon…
The correct answer is A. Create an Amazon EventBridge rule that has a rate expression that will run the rule every 15. Amazon EventBridge scheduled rules with a rate or cron expression are the simplest, fully managed way to invoke a Lambda function on a fixed schedule with no infrastructure to maintain.
Question
An online sales company is developing a serverless application that runs on AWS. The application uses an AWS Lambda function that calculates order success rates and stores the data in an Amazon DynamoDB table. A developer wants an efficient way to invoke the Lambda function every 15 minutes. Which solution will meet this requirement with the LEAST development effort?
Options
- ACreate an Amazon EventBridge rule that has a rate expression that will run the rule every 15
- BCreate an AWS Systems Manager document that has a script that will invoke the Lambda
- CCreate an AWS Step Functions state machine. Configure the state machine to invoke the
- DProvision a small Amazon EC2 instance. Set up a cron job that invokes the Lambda function
How the community answered
(44 responses)- A75% (33)
- B5% (2)
- C14% (6)
- D7% (3)
Why each option
Amazon EventBridge scheduled rules with a rate or cron expression are the simplest, fully managed way to invoke a Lambda function on a fixed schedule with no infrastructure to maintain.
EventBridge supports rate expressions (e.g., rate(15 minutes)) that trigger a target Lambda function on a fixed cadence. This is a native AWS integration requiring only rule creation and a Lambda permission, with zero servers or additional code to manage.
AWS Systems Manager documents are designed for operational runbooks and instance management tasks, not for scheduling recurring Lambda invocations. This approach involves unnecessary complexity and overhead.
Step Functions state machines can invoke Lambda, but using a state machine solely to schedule a periodic invocation requires additional configuration and cost compared to a simple EventBridge rule.
Provisioning an EC2 instance and managing a cron job introduces significant operational overhead including patching, monitoring, and instance management, which contradicts the serverless architecture.
Concept tested: Amazon EventBridge scheduled rules for Lambda invocation
Source: https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-create-rule-schedule.html
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