问题
Some of my personal apps and my professional apps on Heroku are not accessible. They don't have a custom domain linked, so I access them via http://.herokuapp.com
Most of the time, they work great, but often I receive following response from my browser
This site can’t be reached
<myapp>.herokuapp.com’s server IP address could not be found.
DNS_PROBE_FINISHED_NXDOMAIN
The app is up and running. It does not crash (as I haven't made any changes to it in a while). I have tried restarting all dynos, to which the log says that the app is up and running and the db is connected.
Heroku is also not reporting any of their services to being down either. How can I resolve this issue?
I have read a similar question, but the only result coming from it was that Heroku was temporarily down. So please don't link that one again.
Update
Without any of my interference, the application can be reached again on Heroku. How is this possible if Heroku says that there were no problems with their app platforms?
And more important: is there a way to defend against this?
来源：https://stackoverflow.com/questions/60183950/heroku-this-site-can-t-be-reached-dns-probe-finished-nxdomain