I think you’re misunderstanding the context of where Firefox works. Have you ever sat down at someone’s choking machine and wondered how on earth they’re seeing

I think you’re misunderstanding the context of where Firefox works. Have you ever sat down at someone’s choking machine and wondered how on earth they’re seeing it hitting blocking IO because something’s misbehaving in the background drowning out the disks ability to service work? They don’t run in a well controlled server farm, but even there you can expect to see drives behaving poorly leading to io blocking, screwing up the cache performance which in well behaved environments works fine but in degraded environments means you defer to the network with a 0s timeout, meaning you might get no value from the local cache at all but the dual attempt minimizes the “decision time” by instead of waiting for a timeout then requesting it instead requests and goes with what comes back first. Even on a well behaved well managed hosts stuff can wake up and start indexing thinking it’s a good quiet time for that and for short periods you might end up with some slowdown in the cache behavior. Even on that normal multiprocess machine that’s well tuned you’ll sometimes see the cache slowing below the network. The cost is the cache isn’t masking the remote infrastructures true demand. But there’s no spec that says it must afaik. I think the most interesting angle on this is that - infrastructure users serving data are paying for this latency optimization. Is that right? My view is this is the concerning thing - if widely adopted it could materially increase the cost to service providers some of whom operate on thin or negative margins, or with no income at all.