Event triggers for Lambda in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an event trigger in AWS Lambda?

An event trigger is a source that causes a Lambda function to run automatically when a specific event happens, like a file upload or a message arrival.

beginner

Name three common AWS services that can trigger Lambda functions.

Amazon S3 (file uploads), Amazon DynamoDB (table updates), and Amazon API Gateway (HTTP requests) are common event triggers for Lambda.

beginner

How does Amazon S3 trigger a Lambda function?

When a file is added, modified, or deleted in an S3 bucket, it can send an event notification that triggers a Lambda function to run.

intermediate

What is the role of Amazon EventBridge in Lambda triggers?

EventBridge can route events from many AWS services or custom apps to Lambda functions, enabling complex event-driven workflows.

intermediate

Can a Lambda function have multiple event triggers? Explain.

Yes, a Lambda function can be triggered by multiple event sources, allowing it to respond to different types of events in one place.

Which AWS service can trigger a Lambda function when a new file is uploaded?

A Amazon VPC

B Amazon EC2

C Amazon RDS

D Amazon S3

Amazon S3 can send event notifications to Lambda when files are uploaded.

What type of event can Amazon DynamoDB send to trigger Lambda?

A Table updates like inserts or deletes

B EC2 instance launches

C S3 bucket creation

D CloudWatch alarm

DynamoDB streams capture table changes and can trigger Lambda functions.

Which service routes events from many sources to Lambda for complex workflows?

A Amazon EventBridge

B Amazon SNS

C Amazon CloudFront

D AWS IAM

EventBridge routes events from multiple sources to Lambda.

Can a Lambda function be triggered by an HTTP request?

A Yes, but only from Amazon S3

B No, Lambda only triggers on file uploads

C Yes, via Amazon API Gateway

D No, Lambda only triggers on database changes

API Gateway can trigger Lambda functions on HTTP requests.

What happens when multiple event triggers are set for one Lambda function?

A The function runs only on the first trigger

B The function runs when any trigger event occurs

C The function runs only if all triggers happen simultaneously

D The function cannot have multiple triggers

Lambda runs whenever any configured event trigger occurs.

Explain how AWS Lambda uses event triggers to run functions automatically.

Think about what causes Lambda to start without manual action.

List and describe at least three AWS services that can trigger Lambda functions and the types of events they send.

Consider storage, database, and web services.