Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. top(1) showed that only the Cassandra database was consuming CPU. I also shared setting the clocksource in my talks and in my 2015 [Linux tunables] post. What on Earth is Ubuntu doing that results in 30% higher CPU time!?

Speed 126

Speed Java AWS Virtualization 126

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. top(1) showed that only the Cassandra database was consuming CPU. I also shared setting the clocksource in my talks and in my 2015 [Linux tunables] post. What on Earth is Ubuntu doing that results in 30% higher CPU time!?

Speed 40

Speed Java AWS Virtualization 40

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. top(1) showed that only the Cassandra database was consuming CPU. I also shared setting the clocksource in my talks and in my 2015 Linux tunables post. What on Earth is Ubuntu doing that results in 30% higher CPU time!?

Speed 52

Speed Java AWS Virtualization 52

Alex Russell

MARCH 6, 2021

Devices and networks have evolved too: Alex Russell @slightlylate An update on mobile CPUs and the Performance Inequality Gap: Mid-tier Android devices (~$300) now get the single-core performance of a 2014 iPhone and the multi-core perf of a 2015 iPhone. The cheapest (high volume) Androids perform like 2012/2013 iPhones, respectively.

Performance 124

Performance Network Cache Metrics 124

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. In real-life world, most products aren’t even close: an median bundle size today is around 417KB , which is up 42% compared to early 2015. Lighthouse , a performance auditing tool integrated into DevTools.

Performance 145

Performance Cache Network Metrics 145