Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. Since instances of both CentOS and Ubuntu were running in parallel, I could collect flame graphs at the same time (same time-of-day traffic mix) and compare them side by side. Colleagues/Internet I love using [Linux performance tools].

Speed 40

Speed Java AWS Virtualization 40

Smashing Magazine

MAY 20, 2020

This metric is important, but quite vague because it can include anything — starting from server rendering time and ending up with latency problems. For example, for an internet shop, it may be a page with a product list, product details page, shopping cart, checkout, and so on. title, value: report.categories['best-practices'].score,

Performance 98

Performance Metrics Best Practices Code 98

Smashing Magazine

JANUARY 7, 2019

For Mac OS, we can use Network Link Conditioner , for Windows Windows Traffic Shaper , for Linux netem , and for FreeBSD dummynet. Estimated Input Latency tells us if we are hitting that threshold, and ideally, it should be below 50ms. From Fast By Default: Modern loading best practices by Addy Osmani (Slide 19).

Performance 103

Performance Cache Metrics Network 103

Smashing Magazine

JANUARY 11, 2021

CrUX generates an overview of performance distributions over time, with traffic collected from Google Chrome users. But account for the different types and usage behaviors of your customers (which Tobias Baldauf called cadence and cohorts ), along with bot traffic and seasonality effects. You can create your own on Chrome UX Dashboard.

Performance 145

Performance Cache Media Metrics 145

Smashing Magazine

JANUARY 6, 2020

For Mac OS, we can use Network Link Conditioner , for Windows Windows Traffic Shaper , for Linux netem , and for FreeBSD dummynet. Estimated Input Latency tells us if we are hitting that threshold, and ideally, it should be below 50ms. From Fast By Default: Modern loading best practices by Addy Osmani (Slide 19).

Performance 145

Performance Cache Network Metrics 145

Smashing Magazine

AUGUST 9, 2021

You’ve probably heard things like: “HTTP/3 is much faster than HTTP/2 when there is packet loss”, or “HTTP/3 connections have less latency and take less time to set up”, and probably “HTTP/3 can send data more quickly and can send more resources in parallel”. However, it is extremely challenging to actually deploy them at Internet scale.

Transportation 145

Transportation Internet Internet Network 145

Smashing Magazine

AUGUST 22, 2021

This is because HTTP/3 and QUIC mainly help deal with the somewhat uncommon yet potentially high-impact problems that can arise on today’s Internet. Because we are dealing with network protocols here, we will mainly look at network aspects, of which two are most important: latency and bandwidth. Congestion Control.

Performance 105

Performance Network Latency Servers 105