Brendan Gregg

JULY 4, 2021

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. This was a chance to talk about other things I've been working on, such as the present and future of hardware performance.

Performance 52

Performance Latency Hardware Storage 52

VoltDB

JUNE 1, 2017

Earlier this month I spent a week at the OpenStack conference. But once you realize that there are, in fact, several OpenStack conferences happening at the same time and place, it makes more sense. Hardware Optimizers” want to get the maximum utilization out of hardware.

Hardware 56

Hardware Latency Virtualization Cloud 56

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI. A quick check of basic performance statistics showed over 30% higher CPU consumption. in total.

Speed 126

Speed Java AWS Virtualization 126

Brendan Gregg

AUGUST 18, 2019

For example, iostat(1), or a monitoring agent, may tell you your average disk latency, but not the distribution of this latency. For smaller environments, it can be of more use helping eliminate latency outliers. hardware Hardware counter-based instrumentation. Block I/O latency as a histogram.

Latency 68

Latency C++ Cache Programming 68

VoltDB

JUNE 1, 2017

Earlier this month I spent a week at the OpenStack conference. But once you realize that there are, in fact, several OpenStack conferences happening at the same time and place, it makes more sense. Hardware Optimizers” want to get the maximum utilization out of hardware.

Hardware 40

Hardware Latency Virtualization Cloud 40

The Morning Paper

DECEMBER 8, 2019

At the start of November I was privileged to attend HPTS (the High Performance Transaction Systems) conference in Asilomar. On the last morning of the conference Daniel Bittman presented some of the work being done in the context of the Twizzler OS project to explore new programming models for NVM. What about security?

Hardware 56

Hardware Programming Media Storage 56

John McCalpin

JANUARY 22, 2018

Dr. Damon McDougall gave a short presentation on this study at the IXPUG 2018 Fall Conference ( pdf ) — I originally wrote these notes to help organize my thoughts as we were preparing the IXPUG presentation, and later decided that the extra details contained here are interesting enough for me to post it. cmpl $1000000000, %eax.

Latency 40

Latency Hardware Code Testing 40

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI. A quick check of basic performance statistics showed over 30% higher CPU consumption. in total.

Speed 52

Speed Java AWS Virtualization 52

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI. A quick check of basic performance statistics showed over 30% higher CPU consumption. in total.

Speed 40

Speed Java AWS Virtualization 40

Adrian Cockcroft

NOVEMBER 11, 2019

This discussion focuses on hardware, software and operational failure modes. It would take 5–10 minutes after the problem occurred to appear as a problem, then people have to notice and respond to emails or pager text messages, dial into a conference call, and log in to monitoring dashboards before any human response can start.

Latency 52

Latency Engineering Systems Hardware 52

Adrian Cockcroft

NOVEMBER 11, 2019

This discussion focuses on hardware, software and operational failure modes. It would take 5–10 minutes after the problem occurred to appear as a problem, then people have to notice and respond to emails or pager text messages, dial into a conference call, and log in to monitoring dashboards before any human response can start.

Latency 53

Latency Engineering Systems Hardware 53

Brendan Gregg

SEPTEMBER 5, 2017

Here's some output from my zfsdist tool, in bcc/BPF, which measures ZFS latency as a histogram on Linux: # zfsdist. Tracing ZFS operation latency. Which reminds me: I'm helping run the tracing micro conference at Plumbers this year, and I'm also speaking at Kernel Recipes, so if you manage to make it to either, I'll see you there.)

Virtualization 76

Virtualization AWS Engineering Hardware 76

John McCalpin

OCTOBER 16, 2016

“Memory Bandwidth and System Balance in HPC Systems” If you are planning to attend the SuperComputing 2016 conference in Salt Lake City next month, be sure to reserve a spot on your calendar for my talk on Wednesday afternoon (4:15pm-5:00pm).

Architecture 40

Architecture Systems Technology Technology 40

Smashing Magazine

AUGUST 22, 2021

Because we are dealing with network protocols here, we will mainly look at network aspects, of which two are most important: latency and bandwidth. Latency can be roughly defined as the time it takes to send a packet from point A (say, the client) to point B (the server). Two-way latency is often called round-trip time (RTT).

Performance 107

Performance Network Latency Servers 107