Trigger Lambda Function in AWS when the message is present in SQS Queue

Question

I am using AWS Lambda function to process the messages in Queue it's working fine. But i need to execute this Lambda function when messages available or added in SQS queue.

Is it possible to trigger the Lambda function based on SQS queue.Please suggest one method to achieve this goal.

Nappie

Answer 1

Invoking Lambda functions from SQS queues is not directly supported. You can see the list of available triggers here: http://docs.aws.amazon.com/lambda/latest/dg/invoking-lambda-function.html

Possible solutions:

1. Replace SQS queue with Kinesis or DynamoDB. Both can trigger Lambda functions on updates.
2. Inject SNS before SQS. SNS can add items to SQS and trigger Lambda function.

If you don't need near real-time processing, these two options are also valid:

1. Create CloudWatch Event Rule that will trigger the Lambda function every N minutes (e.g. every minute).
2. Create CloudWatch alarm watching ApproximateNumberOfMessagesVisible parameter for your SQS queue. This alarm should publish to an SNS topic, which in turn will trigger Lambda function.

Deacon

Can you please explain this method with details : "Inject SNS before SQS. SNS can add items to SQS and trigger Lambda function" – Nappie

You can publish to SNS topic thought SNS API. SNS will fanout messages to multiple endpoints. – Deacon

I am not well in this AWS, because i am just beginer here. Can you please help me with details – Nappie

See docs.aws.amazon.com/sns/latest/dg/SendMessageToSQS.html for more information. Basically you change your system that pushes messages to your SQS queue; it should post the messages to an SNS topic, which will then fan out to your SQS queue if you set up the queue as a subscriber. – Snuff

When injecting SNS before SQS, how do you guarantee that the lambda function is triggered after the message is added to SQS? – Fallingout

Answer 2

Lambda now supports SQS as a native event source

https://docs.aws.amazon.com/lambda/latest/dg/with-sqs.html

Shellyshelman

Answer 3

Using messages in a SQS queue to trigger a Lambda function is a popular and effective AWS feature. Using SQS Event Source Mapping you can achieve this.For further reference, you can refer to the official AWS documentation on configuring SQS event source mapping:

https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-configure-lambda-function-trigger.html

Dibbuk