Adrian Cockcroft

JANUARY 29, 2023

There is no way to model how much more traffic you can send to that system before it exceeds it’s SLA. This is unfortunate, because we’d really like to be able to build systems that have an SLA that we can share with the consumers of our interfaces, and be able to measure how well we are doing.

Lambda 98

Lambda Latency Cache C++ 98

Adrian Cockcroft

JANUARY 20, 2023

on Myths and Legends of High Performance Computing  — it’s a somewhat light-hearted look at some of the same issues by the leader of the team that built the Fugaku system I mention below. HPCG is led by Japan’s RIKEN Fugaku system at 16 petaflops, which is 3% of it’s peak capacity. Next generation architectures will use CXL3.0

Architecture 52

Architecture Latency Benchmarking AWS 52

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. I also wrote about these topics in detail for my recent [Systems Performance 2nd Edition] book. Ford, et al., “TCP

Performance 52

Performance Latency Hardware Storage 52

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. Microbenchmark os::javaTimeMillis() on both systems. Running this on the two systems saw similar results. Try changing the kernel clocksource.

Speed 126

Speed Java AWS Virtualization 126

ACM Sigarch

MAY 31, 2023

Introduction Memory systems are evolving into heterogeneous and composable architectures. Heterogeneous and Composable Memory (HCM) offers a feasible solution for terabyte- or petabyte-scale systems, addressing the performance and efficiency demands of emerging big-data applications. The recently announced CXL3.0

Latency 52

Latency Hardware Cache Architecture 52

Brendan Gregg

JULY 2, 2021

This is also applicable for people adding it to their own in-house monitoring systems. You likely already have agents running on all your customer systems. There are so many options it's really your own preference based on your existing system and customer environments. biolatency Disk I/O latency histogram heat map.

Latency 145

Latency Cache Energy Systems 145

The Morning Paper

JULY 7, 2019

In addition to availability, our respondents focus most heavily on supporting the following data attributes: “accessibility, accuracy, authoritativeness, freshness, latency, structuredness, ontological typing, connectedness, and semantic joinability.” Learnings and emerging best practices.

Software Engineering 92

Software Engineering Engineering Software Software 92

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. system(".") Block I/O latency as a histogram. BCC is great for canned complex tools and agents.

Latency 68

Latency C++ Cache Programming 68

O'Reilly

DECEMBER 2, 2019

I don’t need more bandwidth for video conferences or movies, but I would like to be able to download operating system updates and other large items in seconds rather than minutes. There are impressive estimates for latency for 5G, but reality has a tendency to be harsh on such predictions. Upcoming events.

Wireless 53

Wireless Serverless IoT Artificial Intelligence 53

Tasktop

JUNE 18, 2019

At Tasktop, we’re gearing up for yet another fantastic conference (Booth P4). As veteran platinum sponsors , we’ve gained a lot of wisdom over the years into how best to maximize the your time at the conference. Here are four tips to get the most out of DOES London 2019: Tip #1 – Develop a plan of attack.

DevOps 74

DevOps Network Software Software 74

cdemi

JUNE 10, 2017

In distributed computer systems, Byzantine Fault Tolerance is a characteristic of a system that tolerates the class of failures known as the Byzantine Generals' Problem ; for which there is an unsolvability proof. Several system architectures were designed that implement Byzantine Fault Tolerance. Atomic Broadcasts.

Blockchain 62

Blockchain Latency Systems C++ 62

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.

Hardware 56

Hardware Programming Media Storage 56

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. Telcos and Fortune 500 corporations used to spend years defining custom systems, down to the last cable.

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%. CLI tools The Cassandra systems were EC2 virtual machine (Xen) instances. Microbenchmark os::javaTimeMillis() on both systems. Running this on the two systems saw similar results. Try changing the kernel clocksource.

Speed 52

Speed Java AWS Virtualization 52

The Morning Paper

SEPTEMBER 5, 2019

For response times (latencies) reporting a simple metric such as ‘average’ is next to useless. Instead we want to understand what’s happening at different latency percentiles (e.g A characteristic of latency distributions is that they have a long tail. Why do we need a new sketch?

Latency 52

Latency Metrics Open Source Java 52

Speed Curve

NOVEMBER 3, 2019

” Tammy, Steve and Cliff at Velocity Conference circa 2015. Traditionally, we’ve spent a lot of time focusing on entitled groups as it relates to performance – fast connection speeds, devices with high-end CPUs, low-latency geographies. Building a more inclusive web.

Education 47

Education Latency Strategy Speed 47

The Morning Paper

JANUARY 23, 2020

1:00pm Eastern Standard Time the Personalisation / Homepage Team for Etsy are in a conference room kicking off a lunch-and-learn session on the personalised feed feature on the Etsy.com homepage. 1:18pm a key observation was made that an API call to populate the homepage sidebar saw a huge jump in latency.

Internet 53

Internet Internet Cache Engineering 53

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. Telcos and Fortune 500 corporations used to spend years defining custom systems, down to the last cable.

Hardware 40

Hardware Latency Virtualization Cloud 40

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. Microbenchmark os::javaTimeMillis() on both systems. Running this on the two systems saw similar results. Try changing the kernel clocksource.

Speed 40

Speed Java AWS Virtualization 40

Brendan Gregg

JULY 2, 2021

This is also applicable for people adding it to their own in-house monitoring systems. You likely already have agents running on all your customer systems. There are so many options it's really your own preference based on your existing system and customer environments. biolatency Disk I/O latency histogram heat map 5.

Open Source 40

Open Source Latency Cache Energy 40

Adrian Cockcroft

NOVEMBER 11, 2019

A resilient system continues to operate successfully in the presence of failures. The system needs to maintain a safety margin that is capable of absorbing failure via defense in depth, and failure modes need to be prioritized to take care of the most likely and highest impact risks. The first technique is the most generally useful.

Latency 52

Latency Engineering Systems Hardware 52

Adrian Cockcroft

NOVEMBER 11, 2019

A resilient system continues to operate successfully in the presence of failures. The system needs to maintain a safety margin that is capable of absorbing failure via defense in depth, and failure modes need to be prioritized to take care of the most likely and highest impact risks. The first technique is the most generally useful.

Latency 53

Latency Engineering Systems Hardware 53

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). McCalpin Presents “Memory Bandwidth and System Balance in HPC Systems”.

Architecture 40

Architecture Systems Technology Technology 40

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

The Netflix TechBlog

NOVEMBER 3, 2022

As the number of Titus users increased over the years, the load and pressure on the system increased substantially. cell): Titus Job Coordinator is a leader elected process managing the active state of the system. For example, a batch workflow orchestration system may create multiple jobs which are part of a single workflow execution.

Cache 224

Cache Latency Traffic Systems 224

Brendan Gregg

SEPTEMBER 5, 2017

What follows are topics that may be of interest to anyone looking to migrate their systems and skillset: scan these to find topics that interest you. ## ZFS ZFS is available for Linux via the [zfsonlinux] and [OpenZFS] projects, and more recently was included in Canonical's Ubuntu Linux distribution: Ubuntu Xenial 16.04 LTS (April 2016).

Virtualization 76

Virtualization AWS Engineering Hardware 76

The Netflix TechBlog

FEBRUARY 9, 2021

The whole system was quite complex, and starting to become brittle. The API server orchestrates backend systems to authenticate the user. Upstream systems had to reopen the tokens to identify the user logging in and potentially manage multiple parallel identity data structures, which could easily get out of sync.

Architecture 221

Architecture Latency Servers Website 221

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

All Things Distributed

OCTOBER 2, 2017

With these requirements in mind, and a willingness to question the status quo, a small group of distributed systems experts came together and designed a horizontally scalable distributed database that would scale out for both reads and writes to meet the long-term needs of our business. This was the genesis of the Amazon Dynamo database.

Internet 128

Internet Internet AWS Performance 128