Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. Colleagues/Internet I love using [Linux performance tools]. But I also love solving issues quickly, and sometimes that means just asking colleagues or searching the Internet. Microbenchmark os::javaTimeMillis() on both systems.

Speed 126

Speed Java AWS Virtualization 126

MachMetrics

OCTOBER 16, 2019

Elon Musk’s need for speed. A lot of coverage on this project is centered (rightfully) around the potential of this project to deliver fast internet to underdeveloped nations at a minimal cost. This ultimately guides us to one conclusion: Speed is incredibly important. Starlink’s Goal: Reduce Internet Latency.

Internet 44

Internet Internet Latency Speed 44

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. Colleagues/Internet I love using Linux performance tools. But I also love solving issues quickly, and sometimes that means just asking colleagues or searching the Internet. Microbenchmark os::javaTimeMillis() on both systems.

Speed 52

Speed Java AWS Virtualization 52

Brendan Gregg

JULY 4, 2021

## References I've reproduced the talk references below, so you can click on links: - [Gregg 08] Brendan Gregg, “ZFS L2ARC,” [link] Jul 2008 - [Gregg 10] Brendan Gregg, “Visualizations for Performance Analysis (and More),” [link] 2010 - [Greenberg 11] Marc Greenberg, “DDR4: Double the speed, double the latency? Ford, et al., “TCP

Performance 140

Performance Latency Hardware Storage 140

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. Colleagues/Internet I love using [Linux performance tools]. But I also love solving issues quickly, and sometimes that means just asking colleagues or searching the Internet. Microbenchmark os::javaTimeMillis() on both systems.

Speed 40

Speed Java AWS Virtualization 40

Brendan Gregg

FEBRUARY 28, 2023

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

Performance 110

Performance Latency Cache Virtualization 110

The Morning Paper

JANUARY 23, 2020

Trade-offs under pressure: heuristics and observations of teams resolving internet service outages , Allspaw, Masters thesis, Lund University 2015. This is part 2 of our look at Allspaw’s 2015 master thesis (here’s part 1 ). 1:32pm the API errors were narrowed down to requests for data on a specific single shop.

Internet 53

Internet Internet Cache Engineering 53