Heroku application changes are deployed with a delay

Question

I have a problem with my production deployment to Heroku.

Staging/testing deployment works fine:

git push staging master

I.e. I can't see my changes instantly

But production doesn't:

git push production master

Deployment is successful, but my changes are not instant.

All files I've change are there.

Cleaning the cache doesn't help:

heroku repo:purge_cache  

I've tried cleaning my browser cache.

I've tried to restart the Heroku instance

heroku restart

I've tried to scale the dyno to 0 and after again to 2

For one week I have the same problem with the same Heroku instance. I was deploying in the evening, I was surprised that my changes didn't apply (they were tested locally and on staging). When I came back the day after, my changes were live.

So maybe it will happen again and just tomorrow it will work again. And maybe not. Has anyone an idea what's wrong?

Answer 1

Did you or someone else enable Preboot?

https://devcenter.heroku.com/articles/preboot

Preboot changes the standard dyno start behavior for web dynos. Instead of stopping the existing set of web dynos before starting the new ones, preboot ensures that the new web dynos are started (and receive traffic) before the existing ones are terminated.