Brendan Gregg

JULY 4, 2021

This was a chance to talk about other things I've been working on, such as the present and future of hardware performance. The video is on [youtube]: The slides are [here] or as a [PDF]: first prev next last / permalink/zoom I work on many areas of performance, but recently I've had a lot of demand to talk about BPF. Ford, et al., “TCP

Performance 52

Performance Latency Hardware Storage 52

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 52

Performance Latency Cache Virtualization 52

HammerDB

OCTOBER 18, 2019

cpupower frequency-info analyzing CPU 0: driver: intel_pstate CPUs which run at the same hardware frequency: 0 CPUs which need to have their frequency coordinated by software: 0 maximum transition latency: Cannot determine or is not supported. hardware limits: 1000 MHz - 4.00 hardware limits: 1000 MHz - 4.00

Benchmarking 63

Benchmarking Performance Hardware C++ 63

The Morning Paper

DECEMBER 8, 2019

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. Therefore any programming abstraction must be low latency and the kernel needs to be kept off the path of persistent data access as much as possible.

Hardware 56

Hardware Programming Media Storage 56

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI.

Speed 52

Speed Java AWS Virtualization 52

Dotcom-Montior

DECEMBER 8, 2021

You cannot virtualize everything…yet. Software services still require physical devices and hardware for them to function. Knowing when and where an error, downtime, or application latency occurs is a critical factor in limiting the impact to users and customers. Asset Management. Postmortems.

Social Media 90

Social Media Monitoring Latency DevOps 90

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI.

Speed 40

Speed Java AWS Virtualization 40

Percona

APRIL 17, 2023

Operating System (OS) settings Swappiness Swappiness is a Linux kernel setting that influences the behavior of the Virtual Memory manager when it needs to allocate a swap, ranging from 0-100. The CFQ works well for many general use cases but lacks latency guarantees. Without further ado, let’s start with the OS settings.

Best Practices 52

Best Practices Design Tuning Database 52

HammerDB

DECEMBER 5, 2020

A full understanding of why this is important requires some knowledge of the evolution of database hardware and software. For TPC-C this meant enough available spindles to reduce I/O latency and for TPC-H enough bandwidth for data throughput. This was both expensive and time consuming to configure.

C++ 40

C++ Benchmarking Virtualization Open Source 40

HammerDB

OCTOBER 12, 2018

As is also the case this limitation is at the database level (especially the storage engine) rather than the hardware level. For this reason sysbench presents a vastly more simplified workload than HammerDB. . driver: intel_pstate CPUs which run at the same hardware frequency: 0 . hardware limits: 1000 MHz - 3.80

Best Practices 40

Best Practices Scalability Performance C++ 40

Alex Russell

APRIL 29, 2021

Now in development in WebKit after years of radio silence, WebXR APIs provide Augmented Reality and Virtual Reality input and scene information to web applications. For heavily latency-sensitive use-cases like WebXR, this is a critical component in delivering a good experience. is access to hardware devices. Offscreen Canvas.

Media 145

Media Games Education Engineering 145

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. Just from a quick search, see this presentation PDF , which digs into oops message components. Many new tools can now be written, and the main toolkit we're working on is [bcc].

Virtualization 76

Virtualization AWS Engineering Hardware 76

SQL Server According to Bob

JANUARY 11, 2020

​​ Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information presented after the date of publication. This White Paper is for informational purposes only.

Servers 40

Servers Cache Media Hardware 40

SQL Server According to Bob

JANUARY 11, 2020

​​ Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information presented after the date of publication. This White Paper is for informational purposes only.

Servers 40

Servers Cache Database Media 40

Smashing Magazine

JANUARY 11, 2021

Estimated Input Latency tells us if we are hitting that threshold, and ideally, it should be below 50ms. Designed for the modern web, it responds to actual congestion, rather than packet loss like TCP does, it is significantly faster , with higher throughput and lower latency — and the algorithm works differently.

Performance 145

Performance Cache Media Metrics 145

All Things Distributed

JANUARY 18, 2012

Amazon DynamoDB offers low, predictable latencies at any scale. Each service encapsulates its own data and presents a hardened API for others to use. A database service that only presents a table interface with a restricted query set is a very important building block for many developers. Consistency. SimpleDBâ??s

Scalability 167

Scalability Database Ecommerce Latency 167