Introduction

A simple AWS Lambda resilience example implementation

Features

• Circuit Breaker with DynamoDB and TTL Specification
• Custom SQS retry control with messageAttributes
• Dead Letter Queue

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NOTE

It works only with asynchronous Lambda calls.

TODO

• Add ExpireTimeStamp as Sorted Key and filter the expired rows, because the TTL would delay over 48 hours depending on table structure and registries
• Add EventBridge integration when retries exceed
• Add different treatments depending on the exception, some errors do not makes sense retry

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Requirements

• aws-cli/2.0.56
• Python/3.7.3
• aws sam cli 1.15.0

Components

dlq_helper

AWS Lambda Layer with helper functions for DLQ retry and Circuit Breaker.

dlq_handler

AWS Lambda that control when should retry and open the circuit

service_a

AWS Lambda A, simulating a simple service that calls another service (b). The service b it is a mock function

AWS Deploy with SAM

make deploy

AWS Test with AWS Cli

# update function name inside Makefile, before execute
make invoke