Using event filtering on Lambda triggers

When using triggers on Lambda functions, some of the AWS services support event filtering which can make your serverless architectures more performant and cost effective.

This was presented at AWS UG Madurai Serverless Day on June 24th, 2023.

1. Using event filtering on Lambda triggers Jones Zachariah Noel N
2. About me https://zachjonesnoel.com 👋 I’m Jones Zachariah Noel N (zachjonesnoel) 🥑 Senior Developer Advocate @ Freshworks ☁ AWS Serverless Hero ⚡ Serverless architect 🚀 AWS UG Bengaluru co-organizer 󰞵 Runs newsletter / blog on The Serverless Terminal
3. Agenda ⚡Look into how Lambda triggers work ⚡Dive into Event filtering on Lambda triggers ⚡Demo
4. AWS Lambda function triggers Synchronous Asynchronous Poll based
5. AWS Lambda function triggers
6. Event filtering Targeted invocation Cost effective Filter expression check Poll based mechanism
7. Understanding event filtering
8. Event filtering supported services DynamoDB Streams Amazon SQS Kinesis Data Streams Amazon MQ Amazon MSK and self managed Apache Kafka
9. Event filtering supported services DynamoDB Streams Amazon SQS Kinesis Data Streams Amazon MQ Amazon MSK and self managed Apache Kafka dynamodb body data data value
10. Event filter expressions
13. Event filter expressions (console)
14. Event filter expressions (SAM template) Events: DynamoDBTable: Type: DynamoDB Properties: Stream: !GetAtt DynamoDBTable.StreamArn StartingPosition: TRIM_HORIZON BatchSize: 100 FilterCriteria: Filters: # Filter pattern to check only inserted action on DynamoDB with the item_type being THREAT - Pattern: '{"eventName": ["INSERT"],"dynamodb":{"NewImage":{"item_type":{"S": [ "THREAT" ]}}}}' # Filter pattern to check only deleted action on DynamoDB - Pattern: '{"eventName": ["REMOVE"]}'
15. Event filter expressions (AWS CLI)
16. • Only the events which match the pattern invoke Lambda fn. • No additional cost, in-fact cost effective. • Manual comparison of events patterns. • Additional times of code. • Unnecessary invocation of Lambda fn.
17. • https://blog.theserverlessterminal.com/trigger-lambda-functions-with-event-filtering • https://blog.theserverlessterminal.com/deep-dive-into-lambda-event-filters-for-dyanmo db • https://aws.amazon.com/about-aws/whats-new/2021/11/aws-lambda-event-filtering-am azon-sqs-dynamodb-kinesis-sources/ • https://github.com/zachjonesnoel/event-filtering-with-dynamo-streams Resources
18. Thank you! https://zachjonesnoel.com @zachjonesnoel zachjonesnoel zachjonesnoel jones-zachariah-noel-n https://theserverlessterminal.com https://blog.theserverlessterminal.com