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

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

ACM Sigarch

MARCH 18, 2019

Existing systems can be studied with measurement, while prospective systems are most often studied by extrapolating from measurements of prior systems or via simulation software that mimics target system function and provides performance metrics. Can one both minimize latency and maximize throughput for unscheduled work? Little’s Law.

Systems 60

Systems Latency Performance Analytics 60

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. How would you time time?

Speed 52

Speed Java AWS Virtualization 52

Brendan Gregg

SEPTEMBER 25, 2021

These strange questions came to the fore back in 2014 when Netflix was switching services from CentOS Linux to Ubuntu, and I helped debug several weird performance issues including one I'll describe here. A Cassandra database cluster had switched to Ubuntu and noticed write latency increased by over 30%. How would you _time_ time?

Speed 40

Speed Java AWS Virtualization 40

Brendan Gregg

JULY 2, 2021

biolatency Disk I/O latency histogram heat map 5. runqlat CPU scheduler latency heat map 10. They need constant updates to keep working across different software versions. As an extreme example, I wrote cachestat(8) while on vacation in 2014 for use on the Netflix cloud, which was a mix of Linux 3.2 patch to Linux 5.12.

Open Source 40

Open Source Latency Cache Energy 40

The Morning Paper

JANUARY 23, 2020

Today we’ll be digging into the analysis of an incident that took place at Etsy on December 4th, 2014. 1:18pm a key observation was made that an API call to populate the homepage sidebar saw a huge jump in latency. This is part 2 of our look at Allspaw’s 2015 master thesis (here’s part 1 ). The last word.

Internet 53

Internet Internet Cache Engineering 53

Brendan Gregg

AUGUST 8, 2017

And here's an excerpt from [Linux] today (include/linux/sched/loadavg.h): #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */ #define EXP_5 2014 /* 1/exp(5sec/5min) */ #define EXP_15 2037 /* 1/exp(5sec/15min) */. Latency was acceptable and no one complained. Linux is also hard coding the 1, 5, and 15 minute constants.

Latency 111

Latency Metrics C++ Systems 111

Abhishek Tiwari

NOVEMBER 3, 2018

In addition, traditional CMS solutions lack integration with modern software stack, cloud services, and software delivery pipelines. Using CDN for the whole website, you can offload most of the website traffic to your CDN which will handle not only large traffic spikes but also reduce the latency of content delivery.

Systems 63

Systems Cache Website Network 63

Alex Russell

APRIL 29, 2021

Delayed three years ( Chrome 40, November 2014 vs. Safari 11.1, A subset ( element.animate() ) has enabled developers to more easily create high-performance visual effects with lower risk of visual stuttering in Chrome and Firefox since 2014. Critical in adapting web content to mobile, particularly regarding multi-touch gestures.

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. They use third-party software like Docker or Kubernetes to simplify their administration. There have been security vulnerabilities, just like there are with any software.

Virtualization 76

Virtualization AWS Engineering Hardware 76

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 117

AWS Airlines Latency Games 117

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. That's where we built many pioneering networking technologies, our next-generation software for customer support, and the technology behind our compute service, Amazon EC2.

AWS 167

AWS Cloud Education Programming 167