AWS CloudWatch is the easiest and most reliable solution to monitor AWS services, including Lambda functions. It's a centralized monitoring service to gather metrics and logs, and also creates alarms based on them. AWS Lambda automatically monitors Lambda functions on your behalf, reporting metrics through CloudWatch.
Monitoring and debugging with AWS CloudWatch
CloudWatch metrics
By default, each time you invoke your function through the Lambda console, it reports the key information about the function resource usage, execution duration, and how much time is billed:
A quick real-time insight can be found by clicking on the Monitoring tab. This page will show a graphical representation of multiple CloudWatch metrics...
