How long does it take for autoscaling to kick in.

I’ve set my app’s concurrency hard limit to 2 and a minimum instance count of 3 however when I load test with a concurrency of 12, I expected to see another vm allocated however this does not happen.

Perhaps I’m missing something?

Strange. I guess the first thing to check would be your autoscale settings: fly autoscale show

I believe by default autoscaling is disabled. So you will want to check it is enabled and also your max value is above 3 (since naturally if your min is 3 but also your max is 3, a new vm won’t be started):

Assuming it’s neither of those, you would also need to consider that auto-scaling won’t be instant. But assuming the concurrent connections persist, and auto-scaling is enabled, and there is capacity etc, the vm should then be started. I’m not sure what the time threshold is as I don’t believe that can currently be set.