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. Colleagues/Internet I love using Linux performance tools. But I'm not completely sure.

Speed 52

Speed Java AWS Virtualization 52

All Things Distributed

JANUARY 18, 2012

a Fast and Scalable NoSQL Database Service Designed for Internet Scale Applications. Today is a very exciting day as we release Amazon DynamoDB , a fast, highly reliable and cost-effective NoSQL database service designed for internet scale applications. Amazon DynamoDB offers low, predictable latencies at any scale. Comments ().

Scalability 167

Scalability Database Ecommerce Latency 167

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

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. Colleagues/Internet I love using [Linux performance tools]. But I'm not completely sure.

Speed 40

Speed Java AWS Virtualization 40

VoltDB

JUNE 1, 2017

Hardware Optimizers” want to get the maximum utilization out of hardware. These systems were designed to have a lifetime of half a decade or more, and rapidly changing hardware meant that the initial deployment had to be sized for 5-7 years out. Latency Optimizers” – need support for very large federated deployments.

Hardware 56

Hardware Latency Virtualization Cloud 56

All Things Distributed

NOVEMBER 15, 2010

For example, the most fundamental abstraction trade-off has always been latency versus throughput. Modern CPUs strongly favor lower latency of operations with clock cycles in the nanoseconds and we have built general purpose software architectures that can exploit these low latencies very well. General Purpose GPU programming.

AWS 136

AWS Latency Programming Architecture 136

All Things Distributed

JULY 13, 2010

In particular this has been true for applications based on algorithms - often MPI-based - that depend on frequent low-latency communication and/or require significant cross sectional bandwidth. There is no more need for hardware tinkering to keep the clusters up and running (I spent many nights doing this; there is no glory in it).

Cloud 118

Cloud AWS Automotive Latency 118

VoltDB

JUNE 1, 2017

Hardware Optimizers” want to get the maximum utilization out of hardware. These systems were designed to have a lifetime of half a decade or more, and rapidly changing hardware meant that the initial deployment had to be sized for 5-7 years out. Latency Optimizers” – need support for very large federated deployments.

Hardware 40

Hardware Latency Virtualization Cloud 40

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. The odd time we hit them, we'll take the "oops message" – a dump of the kernel stack trace and other details from the system log – and search the Internet.

Virtualization 76

Virtualization AWS Engineering Hardware 76

Smashing Magazine

JANUARY 7, 2019

Estimated Input Latency tells us if we are hitting that threshold, and ideally, it should be below 50ms. On the other hand, we have hardware constraints on memory and CPU due to JavaScript parsing times (we’ll talk about them in detail later). A good starting point is to choose a good default stack for your application.

Performance 104

Performance Cache Network Metrics 104

Smashing Magazine

JANUARY 6, 2020

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 Network Metrics 145

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