Interesting post with impressively confusing graphing. Two splines for per color, but stroked differently, with nothing two indicate which of the two y-axes the particular stroke of a color belongs to. The legend shows only color, but stroking an empty box, for some reason.
I had to read it 5 times to understand the meaning...
From what I understand: the more dyno you have, the less each dyno can do. Which is funny when you think about it, becuause your Heroku bill increases linearly with the number of dyno.
"In the below graphs, the response rate is the solid line (and the left y axis); connection errors as a percentage are the dashed line (and the right y axis). The graphs are heavily splined, as suits a meaningless micro-benchmark."