4 ms·

A coworker pointed me to this interesting post noting that in a browser-facing web server (not the same as hits to a datastore), most users will experience the

A coworker pointed me to this interesting post noting that in a browser-facing web server (not the same as hits to a datastore), most users will experience the 99th percentile for at least one resource on the page. http://latencytipoftheday.blogspot.it/2014/06/latencytipoftheday-most-page-loads.html http://latencytipoftheday.blogspot.it/2014/06/latencytipofth...

baruch 12y ago
This is only true if these latency outliers are evenly distributed over time, if they indeed happen once every 30 minutes than only users requesting a page at the same time will be affected.
- aaronharnly 12y ago
  Excellent point, yes.
richardwhiuk 12y ago
That ignores that the 99th percentile is all for the dynamically generated content, rather than any of the scripts/stylesheets/images which should be distributed close to the user on a CDN
- antirez 12y ago
  Sometimes even to create the HTML you serve itself, many DB calls are performed: tens is not very uncommon.
  - pyre 12y ago
    But the root of this thread was talking about users encountering 99th percentile for at least one resource on the page. But the common pattern is that most of the resources on a page are static (even if the generation of the page itself is dynamic). I'll note that I'm excluding API calls here. I don't commonly hear API calls referred to as 'resources' on a page, so I'm assuming that this wasn't being referred to.
    - aaronharnly 12y ago
      XHRs appear under the "Resources" tab of my web inspector, so I guess by that right they're resources on the page :) But you're right -- the latency histograms for static resources are very different than for dynamic resources. So while the probabilities do suggest that most users will encounter at least one 99th percentile latency, it's very different if that latency is for a static resource vs a dynamic one. Thanks for pointing it out.

baruch 12y ago

This is only true if these latency outliers are evenly distributed over time, if they indeed happen once every 30 minutes than only users requesting a page at the same time will be affected.

aaronharnly 12y ago
Excellent point, yes.

richardwhiuk 12y ago

That ignores that the 99th percentile is all for the dynamically generated content, rather than any of the scripts/stylesheets/images which should be distributed close to the user on a CDN

antirez 12y ago
Sometimes even to create the HTML you serve itself, many DB calls are performed: tens is not very uncommon.
- pyre 12y ago
  But the root of this thread was talking about users encountering 99th percentile for at least one resource on the page. But the common pattern is that most of the resources on a page are static (even if the generation of the page itself is dynamic). I'll note that I'm excluding API calls here. I don't commonly hear API calls referred to as 'resources' on a page, so I'm assuming that this wasn't being referred to.
  - aaronharnly 12y ago
    XHRs appear under the "Resources" tab of my web inspector, so I guess by that right they're resources on the page :) But you're right -- the latency histograms for static resources are very different than for dynamic resources. So while the probabilities do suggest that most users will encounter at least one 99th percentile latency, it's very different if that latency is for a static resource vs a dynamic one. Thanks for pointing it out.