When i view my heroku logs on the server (with heroku logs --tail --app myapp) i see something like this:
heroku logs --tail --app myapp
2011-06-21T14:09:25+00:00 app[web.1]:
Looks like the puma server doesn't play well with Heroku. In my project, I tried everything, but it still wouldn't log. I then replaced Puma with Unicorn, and bam, full logs are being shown.