Bug: manually calling refreshSampleRateCalculation does not refresh the sampling decision

[grimmbraten]

Expected Behavior

Invoking a hot Lambda function refreshes the sampling decision. This results in that log level being sometimes lowered to DEBUG based on my set sampleRateValue.

Current Behavior

Invoking a hot Lambda function does not refresh the sampling decision. The sampling decision seems to only happen on Logger initialization.

Code snippet

The Lambda function uses the POWERTOOLS_LOGGER_SAMPLE_RATE environment variable with a value of 0.5.

import { Logger } from '@aws-lambda-powertools/logger';

const logger = new Logger({
  serviceName: 'powertools-logger-test',
});

export const handler = async () => {
  logger.refreshSampleRateCalculation();

  logger.debug('visible sometimes');
  logger.info('@aws-lambda-powertools/logger" = 2.xx');
};

Steps to Reproduce

1. Create a Lambda function according to the provided code snippet.
2. Ensure that the Lambda function uses the POWERTOOLS_LOGGER_SAMPLE_RATE environment variable and that it has a high percentage to lower the log level.
3. Install version 2.15.0 of the @aws-lambda-powertools/logger, deploy the function, and invoke it a few times to confirm that the DEBUG log level is sometimes used.
4. Install version 2.16.0 of the @aws-lambda-powertools/logger, deploy the function, and invoke it a few times. The DEBUG log level will be used for all invocations or none of them (refreshSampleRateCalculation function has no effect).

Possible Solution

No response

Powertools for AWS Lambda (TypeScript) version

latest

AWS Lambda function runtime

20.x

Packaging format used

npm

Execution logs

[boring-cyborg]

Thanks for opening your first issue here! We'll come back to you as soon as we can.
In the meantime, check out the #typescript channel on our Powertools for AWS Lambda Discord: Invite link

[dreamorosi]

Hi @grimmbraten - thank you for opening the issue and reporting this bug.

From a couple of initial tests I can confirm that we have a bug when using the code you shared above. This is related to some changes we introduced in 2.16.0 and this is a regression.

I am still investigating a fix, but it might require some work to accommodate the original (2.15.0) and new (2.16.0) behavior.

I'll share more info here as soon as I have them, in the meantime I'd recommend rolling back to v2.15.0.