5 ms·

Neat. Is there a reason not to tune MySQL to this for all instances?

• scottlamb 8y ago
  > Neat. Is there a reason not to tune MySQL to this for all instances? Yeah, I'd think so. On more modest hardware (less RAM, no 10GbE, etc.), those high buffer sizes may waste RAM that's needed elsewhere. The high number of processes may let some death spiral get much farther into unresponsiveness before stopping it. etc. And most people don't need it. 100k active queries is way too much for most webapps. That means queries average >=1 sec and/or you're peaking at >= 100 kqps. The former sounds painful from a user latency standpoint. The latter isn't the scale of Google, Facebook, Twitter [1], etc. but is still pretty significant. [2] Do you have enough active users that this rate seems reasonable? If not, your best optimization opportunity is figuring out why you have so much unexplained traffic and if you can make it go away...it could be as simple as buggy client-side Javascript in an aggressive retry loop. [1] twitter in particular I think has a pretty high fan-out from user-facing requests to database operations. I imagine most latency is hidden from the user because it happens asynchronously (after writes) and/or in parallel. [2] I'd be curious to see a ranking of public websites by estimated (average/peak/whatever) qps. Seems like something Alexa and such must have but I couldn't find a page with that raw data.