Lambda and Step Functions Essentials Quiz Quiz

Explore key concepts and operations of orchestrating Lambda functions within Step Functions workflows. This quiz covers integration basics, configuration options, error handling, and best practices for combining Lambda with Step Functions for automated task management.

1. Lambda Integration Basics

   Which role does a Lambda function typically play within a Step Functions workflow for processing data sequentially?

   1. Stores workflow execution results
   2. Performs individual tasks as states within the workflow
   3. Tracks workflow execution history
   4. Defines the workflow's overall structure

   Explanation: A Lambda function is commonly used to perform specific tasks as states within a Step Functions workflow, allowing modular and sequential processing. While defining the workflow structure is the responsibility of the workflow's configuration, not the Lambda itself. A Lambda function does not store results or track execution history; these are managed by the workflow engine and its data management features.

2. Error Handling in Workflows

   What feature does Step Functions provide to handle errors from Lambda executions, such as retries or fallback procedures?

   1. Inline code validation
   2. Catch and Retry policies
   3. Throttling rules
   4. Timeout settings

   Explanation: Catch and Retry policies allow Step Functions to handle Lambda errors by retrying operations or redirecting workflow execution to alternative steps. Timeout settings control execution duration, not error handling. Throttling rules are about limiting invocations, which doesn't address error management within workflows. Inline code validation is not related to error recovery.

3. Passing Data Between States

   In a Step Functions workflow using Lambda, what is the purpose of the 'InputPath' parameter in a state definition?

   1. To increase the memory allocation for Lambda
   2. To filter the data sent into a Lambda function
   3. To assign access permissions to Lambda
   4. To determine the number of times a state should run

   Explanation: InputPath filters and selects portions of the state input to pass to a Lambda function, enabling fine control over data flow. Increasing memory allocation is handled in the Lambda configuration, not InputPath. InputPath does not affect iteration counts or permissions; iteration is handled by different states, and permissions are managed elsewhere.

4. State Types in Workflows

   Which state type in Step Functions is most commonly used to invoke a Lambda function?

   1. Pass
   2. Task
   3. Choice
   4. Wait

   Explanation: A Task state is specifically designed to invoke activities like Lambda functions and wait for their result. Wait states introduce delays rather than invoking code, Choice states add branching logic, and Pass states transition data without performing any computation or invocation.

5. Workflow Output Handling

   How does the result from a Lambda function become available for the next state in a Step Functions workflow?

   1. It remains inaccessible to following steps
   2. It is stored in a local variable outside of the workflow
   3. It must be manually copied using external scripts
   4. The result is automatically passed as input to the next state

   Explanation: The output from a Lambda function is automatically made available as input to the next state in the workflow, allowing seamless data flow. No manual copying is required; using external scripts is unnecessary. Results are not hidden from subsequent steps nor stored separately from the workflow data model.

6. Permissions for Lambda Invocations

   What must be configured to allow Step Functions to invoke a Lambda function as part of a workflow?

   1. A version number for the workflow
   2. A data encryption key
   3. An appropriate execution role with Lambda invoke permissions
   4. A workflow timeout setting

   Explanation: An execution role with permissions to invoke Lambda functions must be set up so the workflow can successfully call Lambda actions. Timeout settings manage duration, not permissions. Workflow versions and data encryption keys are unrelated to authorization for invoking Lambdas within a workflow.

7. Timeouts and Retries

   If a Lambda function times out during its execution in a Step Functions workflow, what happens if a retry policy is configured for that state?

   1. The state will re-invoke the Lambda function according to the retry policy
   2. The workflow will ignore the timeout and continue
   3. The workflow will always terminate immediately
   4. The Lambda function will automatically increase its timeout for subsequent runs

   Explanation: With a retry policy configured, Step Functions will attempt to re-invoke the Lambda function after a timeout, according to the retry criteria set in the workflow definition. Ignoring timeouts or increasing timeouts automatically does not occur; these must be configured. The workflow does not terminate unless designed to do so after certain error conditions.

8. Choice State Logic

   In a workflow where a Lambda function returns a status, how can Step Functions use the result to direct the workflow down different paths?

   1. By deleting the workflow's data file
   2. By enabling batch processing mode
   3. By modifying the Lambda memory allocation
   4. By using a Choice state to branch based on Lambda output

   Explanation: A Choice state examines the output of preceding steps like Lambda functions and directs the workflow down different branches accordingly. Changing memory allocation, deleting data files, or enabling batch processing do not affect decision-making or branching within the workflow.

9. Monitoring Workflow Execution

   Which of the following metrics is important for monitoring Lambda functions within Step Functions workflows?

   1. Number of server racks
   2. Default font style used in code
   3. Execution duration of Lambda states
   4. Cable length between servers

   Explanation: Monitoring the execution duration of Lambda states helps identify performance bottlenecks and optimize workflow timing. Server racks and cable length are infrastructure concerns irrelevant to workflows. Font styles in code do not affect Lambda execution or monitoring.

10. Parallel Execution

    How can Step Functions invoke multiple Lambda functions at the same time within a workflow?

    1. By using a Parallel state to run Lambda functions concurrently
    2. By increasing the function's memory allocation
    3. By merging all Lambda code into a single function
    4. By setting all Lambda timeouts to zero

    Explanation: A Parallel state allows multiple Lambda functions to execute at the same time within a workflow, enhancing efficiency for independent tasks. Merging code into a single function sacrifices modularity and is not the same as parallel execution. Changing memory or timeout settings does not enable concurrency directly.