Railsで作ったサイトをHerokuでデプロイしたが急に「Application error」になった

Railsでサイトを制作してそれをHerokuにデプロイしました。上げてから正常に起動していたのですが、ここへきて急に
下記のようなエラーが起きました。上げてからコードは何もいじっていません。

Application error
An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details. You can do this from the Heroku CLI with the command
heroku logs --tail

heroku logs --tailを打った結果がこちらです。

2019-12-27T02:24:32.951716+00:00 heroku[web.1]: Idling
2019-12-27T02:24:32.956541+00:00 heroku[web.1]: State changed from up to down
2019-12-27T02:24:32.971457+00:00 heroku[web.1]: Idling because quota is exhausted
2019-12-27T02:24:34.381356+00:00 heroku[web.1]: Stopping all processes with SIGTERM
2019-12-27T02:24:34.404727+00:00 app[web.1]: - Gracefully stopping, waiting for requests to finish
2019-12-27T02:24:34.416091+00:00 app[web.1]: === puma shutdown: 2019-12-27 02:24:34 +0000 ===
2019-12-27T02:24:34.416350+00:00 app[web.1]: - Goodbye!
2019-12-27T02:24:34.417077+00:00 app[web.1]: Exiting
2019-12-27T02:24:34.614050+00:00 heroku[web.1]: Process exited with status 143
2019-12-27T02:25:31.433106+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/posts/81" host=me.herokuapp.com request_id=80d70b99-1bb3-4703-990a-b2878a25e329 fwd="27.93.15.156" dyno= connect= service= status=503 bytes= protocol=https
2019-12-27T02:25:38.163140+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/posts/81" host=me.herokuapp.com request_id=91370211-b0c2-4bce-8f89-d310d486b2b9 fwd="27.93.15.156" dyno= connect= service= status=503 bytes= protocol=https
2019-12-27T02:26:14.559949+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/" host=me.herokuapp.com request_id=13364e4c-97fe-4890-8d9b-8da5a9cea94d fwd="27.93.15.156" dyno= connect= service= status=503 bytes= protocol=https
2019-12-27T02:31:28.457335+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/" host=me.herokuapp.com request_id=7a0b8707-dd78-44c1-abf9-8e073d9c2a9b fwd="199.59.150.180" dyno= connect= service= status=503 bytes= protocol=http
2019-12-27T02:41:18.949213+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/" host=me.herokuapp.com request_id=d99754d5-c104-45ff-944d-dc7047af5c5e fwd="222.11.22.57" dyno= connect= service= status=503 bytes= protocol=http
2019-12-27T02:46:49.005064+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/" host=me.herokuapp.com request_id=9099a5f7-ee99-4426-b2dc-576ed8c38edf fwd="106.72.42.32" dyno= connect= service= status=503 bytes= protocol=http
2019-12-27T02:46:49.581374+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/favicon.ico" host=me.herokuapp.com request_id=469a59b2-3737-44b1-bc68-b50fcc1f70c2 fwd="106.72.42.32" dyno= connect= service= status=503 bytes= protocol=http
2019-12-27T02:54:58.346934+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/" host=me.herokuapp.com request_id=44fffe45-8ee2-465b-8a53-ddcfeff44ae6 fwd="27.93.15.156" dyno= connect= service= status=503 bytes= protocol=https
2019-12-27T03:07:23.852452+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/" host=me.herokuapp.com request_id=31c9f468-77b2-42c5-8ac4-1245adf1b54b fwd="27.93.15.156" dyno= connect= service= status=503 bytes= protocol=https
2019-12-27T03:07:24.314446+00:00 heroku[router]: at=info code=H82 desc="Free app running time quota exhausted" method=GET path="/favicon.ico" host=me.herokuapp.com request_id=0830e747-5be5-4057-ae71-fece2b759953 fwd="27.93.15.156" dyno= connect= service= status=503 bytes= protocol=https

原因が全くわからないです。何卒アドバイスよろしくお願いします。

yoorwm

2019/12/27 03:33

> Idling because quota is exhausted とか > desc="Free app running time quota exhausted" 使っているプランとか記述してみてください・・・って、「Free app running time」とかある所を見るとフリープラン？どのくらいアクセスされてたか？などを調べてみるとどうでしょうか？