Comment by mememememememo

10 hours ago

Also as someone who looks at latency charts too much, what happens is a request does a lot in series and any little ms you can knock off adds up. You save 10ms by saving 10 x 1ms. And if you are a proxyish service then you are a 10ms in a chain that might be taking 200 or 300ms. It is like saving money, you have to like cut lots of small expenses to make an impact. (unless you move etc. but once you done that it is small numerous things thay add up)

Also performance improvements on heavy used systems unlocks:

Cost savings

Stability

Higher reliability

Higher throughput

Fewer incidents

Lower scaling out requirements.

Wait what? I don't get why performance improvement implies reliability and incident improvement.

For example, doing dangerous thing might be faster (no bound checks, weaker consistency guarantee, etc), but it clearly tend to be a reliability regression.

  • First, if a performance optimization is a reliability regression, it was done wrong. A bounds check is removed because something somewhere else is supposed to already guaratee it won't be violated, not just in a vacuum. If the guarantee stands, removing the extra check makes your program faster and there is no reliability regression whatsoever.

    And how does performance improve reliability? Well, a more performant service is harder to overwhelm with a flood of requests.