The max monthly spend is awesome, I'l probably try it out just because of that :)
Its a bit unclear to me though how exactly the heroku deploy works? Is it basically a replacement for the web dynos that heroku provides, but then still connecting to existing postgres instances for example?
What are the limits for the redis store? I'm using it on heroku but constantly running into max connection issues, if you can improve that experience it is also a great win.
You're exactly right about the Heroku deploy. We convert your app's slug to a Docker image and launch the web process in it. DB & other dynos still run on Heroku.
We don't have any hard connection limits on the redis cache. It's usually not an issue anyway since apps are often distributed across many regions and many redis servers.
you might be running into max connection issues because your library is leaving stale connections. i know this is the case for ruby & php. check if you have timeout set. see this github issue for ruby: https://github.com/redis/redis-rb/issues/524
I have the timeout set to 10 seconds which certainly helps, I think the issue is how gunicorn/gevent handle web requests. I think each request spawns a new redis connection, and as far as I can see there is no global pool I can use :(
On heroku you are limited to 20 connections in the free tier, and it quickly gets expensive.
