[jholman]

Yeah, I dunno squit about Heroku either.

Given that, according to TFA (and it's consistent with some other things I've read) Heroku's bread and butter is Rails apps, and given that, according to TFA, Rails is single-threaded, that (valid) point about concurrency in a single dyno is perhaps not that relevant? You'd think that Heroku would continue to support the routing model that almost all of their marketing and documentation advertises, right? Even if it's a configurable option, and it only works usefully with single-threaded servers?

And if you did do it pull-based, it wouldn't be Heroku's problem to decide how many concurrent requests to send. Leave it to the application (or whatever you call the thing you run on a dyno).

And it doesn't need to be pull-based, if the router can detect HTTP connections closing in dynos, or whatever.

But the idea of pull-based work distribution is pretty straightforward. It's called a message queue.