article thumbnail

In Defence of DOM­Content­Loaded

CSS Wizardry

I never thought I’d write an article in defence of DOMContentLoaded , but here it is… For many, many years now, performance engineers have been making a concerted effort to move away from technical metrics such as Load , and toward more user-facing, UX metrics such as Speed Index or Largest Contentful Paint. log ( window. performance.

Metrics 326
article thumbnail

Bandwidth or Latency: When to Optimise for Which

CSS Wizardry

Where bandwidth deals with capacity, latency is more about speed of transfer 2. If I wanted to speed up the delivery of these images, I am unlikely to get any real gains through optimising them further. The waterfall I used as a demo was exactly that—a demo. To help demystify it, look at the Server Timing API. ↩

Latency 133
Insiders

Sign Up for our Newsletter

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Trending Sources

article thumbnail

Real-World Effectiveness of Brotli

CSS Wizardry

Put another way, file-size savings help you to cram data into lower bandwidth, but if you’re latency-bound, the speed at which those admittedly fewer chunks of data arrive will not change. Taking a very reductive and simplistic view of how files are transmitted from server to client, we need to look at TCP. packet loss).

Latency 269
article thumbnail

USENIX LISA2021 Computing Performance: On the Horizon

Brendan Gregg

I summarized these topics and more as a plenary conference talk, including my own predictions (as a senior performance engineer) for the future of computing performance, with a focus on back-end servers. Ford, et al., “TCP Ford, et al., “TCP Clone Disk],” [link] 2020 - [Moore 20] Samuel K.

article thumbnail

The road to observability demo part 3: Collect, instrument, and analyze telemetry data automatically with Dynatrace

Dynatrace

We also introduced our demo app and explained how to define the metrics and traces it uses. The second part, The road to observability with OpenTelemetry part 2: Setting up OpenTelemetry and instrumenting applications , covers the details of how to set up OpenTelemetry in our demo application and how to instrument the services.

Metrics 166
article thumbnail

USENIX SREcon APAC 2022: Computing Performance: What's on the Horizon

Brendan Gregg

My personal opinion is that I don't see a widespread need for more capacity given horizontal scaling and servers that can already exceed 1 Tbyte of DRAM; bandwidth is also helpful, but I'd be concerned about the increased latency for adding a hop to more memory. Ford, et al., “TCP Ford, et al., “TCP

article thumbnail

Why is Wordpress Slow?

KeyCDN

A WordPress website comprises many parts, including web servers and their settings, different plugins, and themes. We will also discuss how you can speed up your slow WordPress site. One of the most important factors that affect your speed is the server optimization implemented by your web host. Why is WordPress slow?

Cache 52