title: Python app hosted on Heroku suddenly stops working (Error Code H10)
body: <pre><code>2020-02-21T04:40:16.085005+00:00 app[web.1]: [2020-02-21 04:40:16 +0000] [4] [INFO] Using worker: sync
  2020-02-21T04:40:16.090866+00:00 app[web.1]: [2020-02-21 04:40:16 +0000] [14] [INFO] Booting worker with pid: 14
  2020-02-21T04:40:16.169291+00:00 app[web.1]: [2020-02-21 04:40:16 +0000] [22] [INFO] Booting worker with pid: 22
  2020-02-21T04:40:16.285550+00:00 app[web.1]: [2020-02-21 04:40:16 +0000] [30] [INFO] Booting worker with pid: 30
  2020-02-21T04:40:16.885772+00:00 app[web.1]: /app/.heroku/vendor/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py:835: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True or False to suppress this warning.
  2020-02-21T04:40:16.885794+00:00 app[web.1]: 'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
  2020-02-21T04:40:16.991873+00:00 app[web.1]: /app/.heroku/vendor/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py:835: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True or False to suppress this warning.
  2020-02-21T04:40:16.991877+00:00 app[web.1]: 'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
  2020-02-21T04:40:17.098026+00:00 app[web.1]: /app/.heroku/vendor/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py:835: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True or False to suppress this warning.
  2020-02-21T04:40:17.098028+00:00 app[web.1]: 'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
  2020-02-21T04:40:17.810758+00:00 heroku[router]: at=info method=GET path="/" host=overwatchperfectflex.herokuapp.com request_id=c9bde3ed-25fd-418c-a289-79185c729281 fwd="40.94.36.55" dyno=web.1 connect=1ms service=18ms status=200 bytes=3793 protocol=https
  2020-02-21T04:40:18.001787+00:00 heroku[router]: at=info method=GET path="/static/index.js?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=3741ce43-7f21-4bca-9cba-c65e4b899de4 fwd="40.94.36.55" dyno=web.1 connect=0ms service=10ms status=200 bytes=4656 protocol=https
  2020-02-21T04:40:17.950826+00:00 heroku[router]: at=info method=GET path="/static/style.css?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=b39fca0f-0c36-471b-8e9f-356052939856 fwd="40.94.36.55" dyno=web.1 connect=0ms service=9ms status=200 bytes=5526 protocol=https
  2020-02-21T04:40:18.115039+00:00 heroku[router]: at=info method=GET path="/static/sample-screenshot.jpg?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=f2ebea0f-d94a-48b6-ab07-1e6176ea1803 fwd="40.94.36.55" dyno=web.1 connect=0ms service=12ms status=200 bytes=194538 protocol=https
  2020-02-21T04:40:18.128110+00:00 heroku[router]: at=info method=GET path="/static/sample-cards-screen.jpg?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=f187f422-58fa-4c5c-bc8c-5a381b8fc0b6 fwd="40.94.36.89" dyno=web.1 connect=1ms service=14ms status=200 bytes=156857 protocol=https
  2020-02-21T04:40:18.204377+00:00 heroku[router]: at=info method=GET path="/static/sample-screenshot2.jpg?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=a21db7e3-aa67-4b38-aec2-255e603592cf fwd="40.94.36.97" dyno=web.1 connect=1ms service=18ms status=200 bytes=362587 protocol=https
  2020-02-21T04:40:18.257411+00:00 heroku[router]: at=info method=GET path="/" host=overwatchperfectflex.herokuapp.com request_id=a7420d52-8572-40d5-9234-2a12c90b3ab1 fwd="40.94.96.47" dyno=web.1 connect=0ms service=3ms status=200 bytes=3793 protocol=https
  2020-02-21T04:40:18.554730+00:00 heroku[router]: at=info method=GET path="/static/index.js?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=ff63c23b-ee06-4fc5-b2d1-a3bc2bb1bcb8 fwd="40.94.96.47" dyno=web.1 connect=0ms service=3ms status=200 bytes=4656 protocol=https
  2020-02-21T04:40:18.441184+00:00 heroku[router]: at=info method=GET path="/static/style.css?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=31d0bdc2-3a4a-470f-b077-769452833050 fwd="40.94.96.47" dyno=web.1 connect=1ms service=3ms status=200 bytes=5526 protocol=https
  2020-02-21T04:40:18.730303+00:00 heroku[router]: at=info method=GET path="/static/sample-cards-screen.jpg?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=15a50040-049a-4aeb-b61e-cc0f50fbc173 fwd="40.94.96.88" dyno=web.1 connect=1ms service=14ms status=200 bytes=156857 protocol=https
  2020-02-21T04:40:18.722330+00:00 heroku[router]: at=info method=GET path="/static/sample-screenshot.jpg?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=b66d1329-4ddd-476c-b8c5-fbca4817ce18 fwd="40.94.96.47" dyno=web.1 connect=0ms service=14ms status=200 bytes=194538 protocol=https
  2020-02-21T04:40:18.952974+00:00 heroku[router]: at=info method=GET path="/static/sample-screenshot2.jpg?h=1575409895" host=overwatchperfectflex.herokuapp.com request_id=a4798112-a7f5-4ab7-b42e-747efa851bb9 fwd="40.94.96.98" dyno=web.1 connect=0ms service=17ms status=200 bytes=362587 protocol=https
  2020-02-21T04:40:20.591308+00:00 heroku[router]: at=info method=GET path="/favicon.ico" host=overwatchperfectflex.herokuapp.com request_id=efa578d0-bf07-4915-a038-77b65598387c fwd="40.94.36.97" dyno=web.1 connect=1ms service=2ms status=404 bytes=386 protocol=https
  2020-02-21T04:40:21.658366+00:00 heroku[router]: at=info method=GET path="/favicon.ico" host=overwatchperfectflex.herokuapp.com request_id=559223ab-da65-439d-b716-246b656d3eaf fwd="40.94.96.98" dyno=web.1 connect=0ms service=5ms status=404 bytes=386 protocol=https
  2020-02-21T05:16:18.730746+00:00 heroku[web.1]: Idling
  2020-02-21T05:16:18.734547+00:00 heroku[web.1]: State changed from up to down
  2020-02-21T05:16:19.783524+00:00 heroku[web.1]: Stopping all processes with SIGTERM
  2020-02-21T05:16:19.801722+00:00 app[web.1]: [2020-02-21 05:16:19 +0000] [4] [INFO] Handling signal: term
  2020-02-21T05:16:19.802039+00:00 app[web.1]: [2020-02-21 05:16:19 +0000] [30] [INFO] Worker exiting (pid: 30)
  2020-02-21T05:16:19.802390+00:00 app[web.1]: [2020-02-21 05:16:19 +0000] [22] [INFO] Worker exiting (pid: 22)
  2020-02-21T05:16:19.809300+00:00 app[web.1]: [2020-02-21 05:16:19 +0000] [14] [INFO] Worker exiting (pid: 14)
  2020-02-21T05:16:19.935558+00:00 app[web.1]: [2020-02-21 05:16:19 +0000] [4] [INFO] Shutting down: Master
  2020-02-21T05:16:20.000313+00:00 heroku[web.1]: Process exited with status 0
  2020-02-21T17:24:37.126304+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=overwatchperfectflex.herokuapp.com request_id=21677fce-34ce-4437-94ce-31692db20bce fwd="66.249.84.169,66.102.6.200" dyno= connect= service= status=503 bytes= protocol=https
  2020-02-21T17:24:52.887916+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=overwatchperfectflex.herokuapp.com request_id=cbbfe77c-8cf4-4b72-a0e2-865e644bfaa3 fwd="66.201.50.243,66.102.6.201" dyno= connect= service= status=503 bytes= protocol=http
  
  </code></pre>
  
  <p>After months of my application being hosted on heroku, it just randomly shut down a couple of days ago. I did not make any recent changed to the codebase. I've attached what I believe the relevant logs concerning this problem. I've done my research and apparently heroku automatically does this if your app isn't getting enough traffic, but I believe this to be false since my previous projects hosted on Heroku still work fine. </p>
  
  <p>*My app works perfectly if hosted locally.</p>