AWS DevOps I/O Configuration & Sensors 5 — Questions and Answers
Question 1: An engineer needs to fan out sensor events from a single IoT topic to multiple independent downstream processors. Which AWS architecture pattern achieves this most efficiently?
- IoT rule → single Lambda → synchronous chained calls
- IoT rule action → SNS topic → multiple SQS queues (Correct answer)
- IoT rule → DynamoDB stream → Lambda
- IoT rule → S3 → S3 event notifications
Correct answer: IoT rule action → SNS topic → multiple SQS queues
Routing IoT messages to SNS and subscribing multiple SQS queues enables fan-out to independent consumers without tight coupling between processors.
Question 2: In AWS Systems Manager, which document type defines a configuration remediation workflow that can automatically correct non-compliant EC2 instance settings?
- Command document (AWS-type Command)
- Automation document (AWS-type Automation) (Correct answer)
- Session document (AWS-type Session)
- Package document (AWS-type Package)
Correct answer: Automation document (AWS-type Automation)
SSM Automation documents define multi-step remediation workflows that can automatically correct configuration drift on EC2 instances.
Question 3: A CodePipeline pipeline uses a custom action with an external CI system. Which mechanism does the external system use to report job success or failure back to CodePipeline?
- SQS message to CodePipeline's internal queue
- S3 object tagging on the artifact bucket
- CloudWatch Events rule triggering StartPipelineExecution
- PutJobSuccessResult / PutJobFailureResult API calls (Correct answer)
Correct answer: PutJobSuccessResult / PutJobFailureResult API calls
External workers poll for jobs using PollForJobs and report outcomes using PutJobSuccessResult or PutJobFailureResult, which are the only way to signal completion to CodePipeline.
Question 4: An IoT sensor publishes temperature readings every second. A DevOps team wants to detect anomalies using ML without writing custom models. Which AWS service provides this natively?
- Amazon Lookout for Metrics (Correct answer)
- Amazon Rekognition
- AWS Glue DataBrew
- Amazon Comprehend
Correct answer: Amazon Lookout for Metrics
Amazon Lookout for Metrics uses ML to automatically detect anomalies in time-series data like sensor readings without requiring custom model development.
Question 5: When configuring a CodeBuild project to cache dependencies between builds, which cache type stores the cache on the build host's local disk for the fastest retrieval?
- S3 cache
- ECR layer cache
- LOCAL cache (Correct answer)
- EFS cache
Correct answer: LOCAL cache
CodeBuild LOCAL cache stores files on the build host's ephemeral disk, providing the fastest cache retrieval since no network I/O is required.
Question 6: A DevOps team deploys configuration updates to thousands of IoT devices using AWS IoT Jobs. Which job configuration parameter prevents overwhelming devices with simultaneous updates?
- TimeoutConfig inProgressTimeoutInMinutes
- AbortConfig failureType threshold
- PresignedUrlConfig expiresInSec
- RolloutConfig maximumPerMinute rate limit (Correct answer)
Correct answer: RolloutConfig maximumPerMinute rate limit
The RolloutConfig maximumPerMinute parameter throttles how many devices receive the job per minute, preventing fleet-wide simultaneous update storms.
Question 7: Which AWS Config managed rule evaluates whether EC2 instances have the Systems Manager agent running, confirming they can receive remote configuration and I/O commands?
- ssm-agent-installed
- ec2-ssm-patch-compliance
- ec2-instance-managed-by-systems-manager (Correct answer)
- managed-instance-inventory-check
Correct answer: ec2-instance-managed-by-systems-manager
The ec2-instance-managed-by-systems-manager AWS Config managed rule checks that EC2 instances are registered and reachable by SSM, confirming agent connectivity.
AWS DevOps I/O Configuration & Sensors 5
An engineer needs to fan out sensor events from a single IoT topic to multiple independent downstream processors.
Which AWS architecture pattern achieves this most efficiently?