@nCubed, are you using Advanced Logging Controls (https://docs.aws.amazon.com/lambda/latest/dg/monitoring-cloudwatchlogs-advanced.html) feature?

@hjgraca Looks like we were using the OOB "text" format. I updated to "json" format and the structured logging is useless because the message is now an escaped string.

{
    "timestamp": "2025-02-24T13:36:06.483Z",
    "requestId": "f6e6096f-5d28-57bd-99a3-6959252efdd6",
    "level": "info",
    "traceId": "Root=1-67bc<snip>"
    "message": "{\"cold_start\":false,\"xray_trace_id\":\"1-67bc<snip>\",\"function_name\":\"<snip>\",\"function_version\":\"$LATEST\",\"function_memory_size\":350,\"function_arn\":\"arn:aws:lambda:us-east-2:<snip>\",\"function_request_id\":\"f6e6096f-<snip>\",\"timestamp\":\"2025-02-24T13:36:06.4837199Z\",\"level\":\"Error\",\"service\":\"<snip>\",\"name\":\"AWS.Lambda.Powertools.Logging.Logger\",\"message\":\"<snip>\"}"
}

Am I missing a configuration setting?

I was just trying to understand if you were using ALC because only ALC can change the log level.
Also in ALC mode Logging should be outputting LogLevel and not Level as you are showing and the json should not be inside a string.

Give me some time I am going to try reproduce your scenario, top level statement lambda correct? can you share a snippet of code that could help debug?

Thanks.

Yes. Top level statement.

I'm going to need to run some more tests. In our actual lambdas, changing the ALC from text to json causes the json message to be an escaped string. In the standard sample I've shared with you in the past, the output is correctly structured.

This is a lower priority for us, so it may be a bit. However, I can confirm that in the message is a fully escaped string instead of structured json in our actual lambdas. Both this sandbox lambda and our actual lambdas all use the exact same build/deploy process, as well as same function definitions using Terraform.

Thanks, you should not need to enable ALC, was just wondering if you had enabled, but will try and get to the bottom of that.

Hi @nCubed I was not able to reproduce your issue. On our side from Lambda to CloudWatch everything seems fine.
But I want to understand your issue better, I might be missing something.
Please send me an email with your availability so we can have a chat to [email protected]

Thank you.

Hi @hjgraca - we're working through a release this week. I'm going to set aside another timeslot in the next day or two and re-validate the issue I encountered on my end. The log files still exist, so we at least have that as some evidence. Once I'm able to repro the issue, I'll ping you here and shoot you an email. Thanks for the follow up.

Hi @nCubed.
We had a meeting regarding this issue and we might have found the culprit.
We are calling Console.WriteLine and not the appropriate Console.Error, this will indeed affect the output to CloudWatch since the default log level is Info.

Regarding this line
2025-02-24T13:36:06.483Z f6e6096f-5d28-57bd-99a3-6959252efdd6 info
Are you doing any other logging without Powertools maybe using context.Logger? Where do you see it?

I am working on Logging v2 at the moment, but will do a fix for this and hopefully can get it out this week or next week.
Thanks for reporting the issue

Hey @hjgraca - sorry for the delay on my side. We have been heads down; didn't quite expect to take this long. I'll still try to reproduce on my end when time permits.

Heads up... I will be submitting another bug for Tracing where it throws an exception which masks the underlying exception from the app. I saw a similar bug in the issues and it was closed. So this may be another avenue where the Trace tools can mask the system exception.

We are going to close this issue for now since we haven't heard from you - if the issue persists, please reopen with the info above.

@nCubed I found the issue, and will be fixed on the next release of Logging, which will be v2.
Thanks for bringing this to our attention.

The issue is that on top level statements the LambdaLogger, hijacks at the last time the Console.SetOut to their log, so I had to hijjack back to our log format :)
So now instead of this

you get only the json as you should and do in non top level lambdas

Fix:
Release 1.4.0

• Logging 1.7.0
• Logging 2.0.0-preview.1