Reloading HAProxy is part of the SmartStack architecture, IIRC. SmartStack/synapse does polling on say, ZooKeeper or Docker or whatever, generates a new HAProxy configuration and then reloads it.
That's an important detail, as it explains why the tests aren't entirely flawed: Testing 10 reloads every second really distorts the numbers, assuming a reload every hour, or every few hours is more realistic. But if reloads are part of what amounts to doing live testing on a large part of live traffic -- then the exercise makes more sense.
And to be sure; being able to do ten reloads every second with few ill effects enables different, more nimble systems engineering.
But if we assume 2000 requests per second, per box - fighting ~100 reset connections a day (assuming two ha-proxy reconfigs) doesn't really seem worth the effort - packet loss and other outages would probably(?) domminate anyway.
> Testing 10 reloads every second really distorts the numbers, assuming a reload every hour, or every few hours is more realistic.
It depends on what you do. I've seen shops (successfully and, IMO, correctly) scaling AWS instances for services with a threshhold of every fifteen minutes, and I've seen Mesos clusters dynamically spinning up web instances much more nimbly than that (think every two minutes under spiky load--the instances would come up in five seconds, so it didn't hurt to down them).
Sure, but if it doesn't work there, I don't trust it to work if, say, a piece of my scheduler goes nuts and suddenly is upping and downing containers every few seconds. The problem remains, it's just not as acute and still must be fixed.
