0
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

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.

*My app works perfectly if hosted locally.

  • What happens when you try re-deploying your app? – Gino Mempin Feb 23 '20 at 03:54
  • @GinoMempin I've tried putting it on maintenance mode, resetting the dyno's then redoploying. Doesn't work. –  Feb 23 '20 at 04:08
  • 1
    What does "*doesn't work*" mean? Do you get a new error message when you try to re-deploy? Or does it also crash after some time? Also, your logs show a "App crashed" error at the end. I'm guessing, the dyno shut down (if you are using a free dyno, then this is expected to happen regularly), and then something happened when the dyno and your app restarted. – Gino Mempin Feb 23 '20 at 04:25
  • @GinoMempin Yea I'm using a free dyno? I don't understand why this would happen regularly. Does this mean I have to redeploy my application under a new heroku app until the dyno fails if I want to continue using the free version? –  Feb 25 '20 at 19:00

1 Answers1

1

1st:

heroku[router]: at=error code=H10 desc="App crashed"

From the Heroku Error Code docs, H10 means "App crashed":

A crashed web dyno or a boot timeout on the web dyno will present this error.

2010-10-06T21:51:10-07:00 heroku[web.1]: Process exited  
2010-10-06T21:51:12-07:00 heroku[router]: at=error code=H10 desc="App  
crashed" method=GET path="/" host=myapp.herokuapp.com fwd=17.17.17.17
dyno= connect= service= status=503 bytes=

2nd:

It seems you are using a free dyno, that goes to sleep after a 30-minute period of no activity.

2020-02-21T04:40:21.658366+00:00 heroku[router] ... (last access) ...  
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

You can't do anything about this except for buying non-sleeping dynos. When the dyno goes to sleep, it stops all processes running on that dyno, which includes your app.

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

Now, when Heroku sent the SIGTERM signal to your app, something happened in the time between the abnormal termination (SIGTERM) and the app restart that caused it to crash. Maybe your app failed to handled a not so graceful exit (ex. file I/O, DB connection not closed), so restarting from an abnormal state caused it to crash.

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

So...

*My app works perfectly if hosted locally.

Great.

Maybe you need to also check what happens when your app is abnormally terminated. Run it locally, then send it the same SIGTERM signal. Get your app's PID then see How can I send a signal from a python program?.

Gino Mempin
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