How to create CloudWatch alarm for memory usage on lambda based on CloudWatch logs

Question

I have the below log in CloudWatch and would like to create an alarm when average of Max memory usage exceeds 400 MB.

REPORT RequestId: xxxxxx-xxx-xxx-xxx-xxx Duration: 5750.91 ms Billed Duration: 5751 ms Memory Size: 512 MB Max Memory Used: 150 MB Init Duration: 1562.14 ms

Answer 1

Unfortunately, Memory Used is not one of the standard AWS Lambda function metrics collected by Amazon CloudWatch.

You would need to:

• Create metrics from log events using filters - Amazon CloudWatch Logs to parse that log
• Configure the filter to find that output line and extract the "Memory Used" figure
• Use that extracted figure to populate a new CloudWatch metric
• Create an Alarm on that metric

Let us know how it goes!