AWS Cloudwatch/Lambda - scheduled event is triggered too often

2
votes

i created an AWS Lambda function, and created a scheduled event rule in Cloudwatch to trigger it every 5 minutes : Schedule Cron expression : 0/5 * * * ? *

The problem is that when looking at the logs, the Lambda seems to be executed every 1~2 minute.

I checked the CRON expression, it seem correct because AWS shows previews of the next triggers. I also tried with a rate expression, but i still have the same issue.

I tooks a look at cloudwatch metrics : - The scheduled event seems fine, it triggered once every 10minutes - The lambda invocation metric show that it is invoked more often

Any help ?

1
amazon-web-servicesaws-lambdaamazon-cloudwatch
Could something else be triggering your lambda? - Lou O.
@LouO. i only used 1 trigger with SQS. I verified by disabling the Event rule, and the lambda stopped logging, so i guess it's fine on this side - Sebastien H.
Could you please edit your question to better explain what you have configured? The title mention SQS, but your question mentions a cron trigger. The correct way to associate Lambda with an Amazon SQS queue is to create a trigger that will invoke the Lambda function whenever a message goes into the SQS queue. A cron expression is not required. Please provide us more information about your setup. - John Rotenstein
Are the previous executions of the Lambda function completing successfully (with no errors or timeouts)? - John Rotenstein
Can you try the alternate format of rate(5 minutes)? See: Schedule Expressions Using Rate or Cron - AWS Lambda - John Rotenstein

1 Answers

3
votes

Thanks @JohnRotenstein for the lead,

the issue came from the returned result from the NodeJS promise. If the JS handler doesn't give back any result inside the returned promise, lambda considers the execution as a failure.

In my case i simply had to return a value (even null) so that the execution completes successfully. Otherwise it looks like lambda will to re-execute the code 1~2 minutes later