I have an AWS Lambda that runs a few times a day. Being a good boy scout, I have an alert on the Errors metric for the lambda. Every once in a while, it fires. Examining logs is useless: they indicate the job rain successfully to completion. Pointing & clicking around the UI, I discover "monitoring tools". Cool! I enable "Enhanced monitoring" and "Lambda service traces".
I'm now greeted with alerts all over the place: apparently, these features require your lambda runtime to have a particular version of glibc installed, and mine doesn't. This takes down the entire lambda. I point & click some more & find that I have configured my lambda to "automatically update to the most recent and secure runtime version."
I sigh & disable "Enhanced monitoring" and "Lambda service traces". I then disable my alert. AWS: home to good enough code.