The free version of Papertrail logging with Heroku has a daily log volume limit of 10 MB:
https://elements.heroku.com/addons/papertrail
What happens when this limit is reached? Does the entire Heroku application fail/crash for the rest of the day? I tried testing this but could not identify what was occurring, so it's not clear to me if the limit even properly triggered for some reason.
Logs will be discarded once you've hit the 10MB, so new logs for that day will not be stored. They'll still be available via Logplex (usually by viewing heroku logs) but Papertrail won't have them for you.