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 103

Performance Latency Cache Virtualization 103

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. The change was obvious in the production graphs, showing a drop in write latencies: Once tested more broadly, it showed the write latencies dropped by 43%, delivering slightly better performance than on CentOS.

Speed 103

Speed Java AWS Virtualization 103

All Things Distributed

JANUARY 6, 2016

A region in South Korea has been highly requested by companies around the world who want to take full advantage of Korea’s world-leading Internet connectivity and provide their customers with quick, low-latency access to websites, mobile applications, games, SaaS applications, and more.

AWS 105

AWS Cloud Games Latency 105

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 52

Performance Latency Hardware Storage 52

Brendan Gregg

JULY 2, 2021

biolatency Disk I/O latency histogram heat map. runqlat CPU scheduler latency heat map. Here are the top ten tools you can run and present as a generic BPF observability dashboard, along with suggested visualizations: Tool Shows Visualization. execsnoop New processes (via exec(2)) table. opensnoop Files opened table.

Latency 144

Latency Cache Energy Systems 144

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

MachMetrics

OCTOBER 16, 2019

However, there is excitement around Starlink for other reasons – namely, the implications it might have for internet speed and latency – even by just a small amount (20 milliseconds on average). Starlink’s Goal: Reduce Internet Latency. What does Starlink and Reduced Latency have to do with me?

Internet 44

Internet Internet Latency Speed 44

All Things Distributed

OCTOBER 25, 2018

The new AWS Africa (Cape Town) Region will have three Availability Zones and provide lower latency to end users across Sub-Saharan Africa. In 2015, we expanded our presence in the country, opening an AWS office in Johannesburg. It is our first Region in Africa, and we're shooting to have it ready in the first half of 2020.

AWS 167

AWS Cloud Education Programming 167

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 ). 1:06pm reports of the personalised homepage having issues start appearing from multiple sources.

Internet 53

Internet Internet Cache Engineering 53

Brendan Gregg

MAY 16, 2017

I previously wrote about Netflix in [2015] and [2016], and if you are interested in what it's like to work here, I already covered much in those posts. A latency outlier issue that happened every 15 minutes. I've now worked at Netflix for over three years. Time flies! Java core dump analysis for a crashing JVM. -

Java 75

Java Entertainment Engineering Scalability 75

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. The change was obvious in the production graphs, showing a drop in write latencies: Once tested more broadly, it showed the write latencies dropped by 43%, delivering slightly better performance than on CentOS.

Speed 40

Speed Java AWS Virtualization 40

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

Brendan Gregg

SEPTEMBER 25, 2021

A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. The change was obvious in the production graphs, showing a drop in write latencies: Once tested more broadly, it showed the write latencies dropped by 43%, delivering slightly better performance than on CentOS.

Speed 52

Speed Java AWS Virtualization 52

Brendan Gregg

MAY 8, 2021

Update: Some modern drives after 2015 are sealed with [helium].) From these outputs I try to determine if the problem is: - **The workload**: High-latency disk I/O is commonly caused by the workload applied. Rotational disks have extra latency from head seeks for random I/O, and spin ups from the idle state. Hit Ctrl-C to end.

Performance 40

Performance Latency Speed Systems 40

The Netflix TechBlog

DECEMBER 17, 2019

Passive instances across regions are also possible, though it is recommended to operate in the same region as the database host in order to keep the change capture latencies low. Production usage DBLog is the foundation of the MySQL and PostgreSQL Connectors at Netflix, which are used in Delta. Beresford, and Boerge Svingen.

Database 203

Database Traffic Transportation Open Source 203

Brendan Gregg

AUGUST 8, 2017

Some people have found values that seem to work for their systems and workloads: they know that when load goes over X, application latency is high and customers start complaining. Latency was acceptable and no one complained. Load averages measured in a modern tool. But there aren't really rules for this. One system with a ratio of 1.5

Latency 111

Latency Metrics C++ Systems 111

The Netflix TechBlog

DECEMBER 17, 2019

Passive instances across regions are also possible, though it is recommended to operate in the same region as the database host in order to keep the change capture latencies low. Production usage DBLog is the foundation of the MySQL and PostgreSQL Connectors at Netflix, which are used in Delta. Beresford, and Boerge Svingen.

Database 217

Database Traffic Transportation Open Source 217

Alex Russell

JANUARY 30, 2024

JavaScript-Heavy # Since at least 2015, building JavaScript-first websites has been a predictably terrible idea, yet most of the sites I trace on a daily basis remain mired in script. [1] If you or your company are able to generate a credible worldwide latency estimate in the higher percentiles for next year's update, please get in touch.

Performance 98

Performance Network Mobile Speed 98

Brendan Gregg

JULY 2, 2021

biolatency Disk I/O latency histogram heat map 5. runqlat CPU scheduler latency heat map 10. Here are the top ten tools you can run and present as a generic BPF observability dashboard, along with suggested visualizations: Tool Shows Visualization 1. execsnoop New processes (via exec(2)) table 2. opensnoop Files opened table 3.

Open Source 40

Open Source Latency Cache Energy 40

The Netflix TechBlog

NOVEMBER 22, 2019

December 3 11:30am-12:30pm NFX 208 Netflix’s container journey to bare metal Amazon EC2 Andrew Spyker , Compute Platform Engineering Manager Abstract : In 2015, Netflix started supporting containers as part of their compute platform. We explore all the systems necessary to make and stream content from Netflix.

AWS 38

AWS Entertainment Open Source Benchmarking 38

Alex Russell

MARCH 6, 2021

Devices and networks have evolved too: Alex Russell @slightlylate An update on mobile CPUs and the Performance Inequality Gap: Mid-tier Android devices (~$300) now get the single-core performance of a 2014 iPhone and the multi-core perf of a 2015 iPhone. The cheapest (high volume) Androids perform like 2012/2013 iPhones, respectively.

Performance 127

Performance Network Cache Metrics 127

All Things Distributed

AUGUST 16, 2011

There are different considerations when deciding where to allocate resources with latency and cost being the two obvious ones, but compliance sometimes plays an important role as well. The move to the cloud is projected by 2015 see a reduction of 30% in IT infrastructure costs, which amounts to $7.2

AWS 102

AWS Government Big Data Cloud 102

Smashing Magazine

AUGUST 9, 2021

You’ve probably heard things like: “HTTP/3 is much faster than HTTP/2 when there is packet loss”, or “HTTP/3 connections have less latency and take less time to set up”, and probably “HTTP/3 can send data more quickly and can send more resources in parallel”. Why Do We Need HTTP/3?

Transportation 145

Transportation Internet Internet Network 145

All Things Distributed

APRIL 4, 2017

This enables customers to serve content to their end users with low latency, giving them the best application experience. In 2011, AWS opened a Point of Presence (PoP) in Stockholm to enable customers to serve content to their end users with low latency. In 2014 and 2015 respectively, AWS opened offices in Stockholm and Espoo, Finland.

AWS 112

AWS Airlines Latency Games 112

Adrian Cockcroft

AUGUST 1, 2022

photo by Adrian I gave a talk at Monitorama in Portland Oregon in June, which set out the idea that carbon is just another metric to monitor, and that in a few years most of the monitoring and performance tuning tools are going to be reporting and optimizing for carbon alongside latency, throughput, availability and cost.

AWS 52

AWS Virtualization DevOps Latency 52

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 Servers 145

Smashing Magazine

JANUARY 7, 2019

Estimated Input Latency tells us if we are hitting that threshold, and ideally, it should be below 50ms. In real-life world, most products aren’t even close: an average bundle size today is around 400KB , which is up 35% compared to late 2015. On a middle-class mobile device, that accounts for 30-35 seconds for Time-To-Interactive.

Performance 105

Performance Cache Network Metrics 105

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