This is exactly what I was thinking as I was reading this blog post. I did a double take when I read that because it makes absolutely no sense at all. It seems

This is exactly what I was thinking as I was reading this blog post. I did a double take when I read that because it makes absolutely no sense at all. It seems to imply that their fabled web serving stack never actually worked as advertised but no one cared or complained publicly enough to make Heroku explain the issue. I just can't believe that Heroku had like 2-5 routers in their entire stack. I'm wondering if maybe they have some kind of simple sharding for routers based on the app name so all hash values go to a small set of routers. I can understand if that was the case how large numbers of small applications would seem to developers and heroku customer support to be using a per application queue. Of course, this would break down the instant there were very large applications served on heroku that would overwhelm the small number of routers assigned to each shard bucket.