Logs: Not sent when there are always logs being collected under the flush timeout

[lucas-zimerman]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/react

SDK Version

10.24.0

Framework Version

No response

Link to Sentry event

No response

Reproduction Example/SDK Setup

let counter = 0;
const sender = () => {
  Sentry.logger.info(`never flushed number ${counter}`);
  setTimeout(sender, 2000);
};

sender();

Steps to Reproduce

run the snippet code and you will notice that even after minutes there will be no logs in spotlight/sentry

Expected Result

logs being captured

Actual Result

no logs being captured.

Additional Context

I read the client code on the latest commit and it seems the same as the one that presents the issue.
The main problem is for every log captured, the flush timeout is reset to a new timeout delay.
If we have a constant inflow of logs, we will never send those logs.

EDIT: It seems like it's actually sent, but only when we reach 100logs, meaning that the sample loop takes 2 minutes and 33 seconds before sending it.

spotlight tricked me in thinking the logs were partially sent but all of them were correctly sent at sentry.io

[linear]

JS-1163

[lucas-zimerman]

Similar to getsentry/sentry-react-native#5378 since we use the same flush logic.

[andreiborza]

Hi @lucas-zimerman, thanks for writing in.

Yea, we reset the flush timeout every time a new log comes in which means you'll be able to delay the flushing by quite a bit with slow-logging.

We'll switch to not reset the timeout as new logs come in and flush earlier, thanks again for bringing this up!