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. Note that Ubuntu also has a frame to show entry into vDSO (virtual dynamic shared object). Microbenchmark os::javaTimeMillis() on both systems.

Speed 40

Speed Java AWS Virtualization 40

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 110

Performance Latency Cache Virtualization 110

SQL Performance

APRIL 8, 2019

Back on December 5, 2017, Microsoft announced that they were using AMD EPYC 7551 processors in their storage-optimized Lv2-Series virtual machines. This processor has a base clock speed of 2.0GHz, with an all-core boost speed of 2.55GHz, and a max boost clock speed of 3.0GHz. The L3 cache size is 64MB. Azure Lsv2 Details.

Azure 42

Azure Virtualization Storage Benchmarking 42

Dynatrace

FEBRUARY 4, 2021

As a discipline, SRE focuses on improving software system reliability across key categories including availability, performance, latency, efficiency, capacity, and incident response. ” According to Google, “SRE is what you get when you treat operations as a software problem.” SRE drives a “shift left” mindset.

Engineering 252

Engineering DevOps Government Latency 252

Scalegrid

JANUARY 12, 2024

Various forms can take shape when discussing workloads within the realm of cloud computing environments – examples include order management databases, collaboration tools, videoconferencing systems, virtual desktops, and disaster recovery mechanisms. This applies to both virtual machines and container-based deployments.

Cloud 130

Cloud Virtualization Storage Efficiency 130

VoltDB

JUNE 19, 2017

Unfortunately, this means that the age-old Telco bugbears will rear their ugly heads again, including latency. 5G, as a fundamental requirement, mandates a 1 millisecond latency from the datasource to its destination. In fact, 5G has plenty of valid use cases, one of which is virtual reality. This requires 1 ms network latency.

Latency 40

Latency Retail Virtualization Hardware 40

VoltDB

JUNE 19, 2017

Unfortunately, this means that the age-old Telco bugbears will rear their ugly heads again, including latency. 5G, as a fundamental requirement, mandates a 1 millisecond latency from the datasource to its destination. In fact, 5G has plenty of valid use cases, one of which is virtual reality. This requires 1 ms network latency.

Latency 40

Latency Retail Virtualization Hardware 40

Scalegrid

MARCH 14, 2024

It provides significant advantages that include: Offering scalability to support business expansion Speeding up the execution of business plans Stimulating innovation throughout the company Boosting organizational flexibility, enabling quick adaptation to changing market conditions and competitive pressures.

Strategy 130

Strategy Cloud Artificial Intelligence Infrastructure 130

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 140

Performance Latency Hardware Storage 140

Dynatrace

FEBRUARY 4, 2021

As a discipline, SRE focuses on improving software system reliability across key categories including availability, performance, latency, efficiency, capacity, and incident response. ” According to Google, “SRE is what you get when you treat operations as a software problem.” SRE drives a “shift left” mindset.

Engineering 173

Engineering DevOps Government Latency 173

Dynatrace

JANUARY 13, 2022

For example, data collected on load actions can include navigation start, request start, and speed index metrics. Virtually any application with a user interface can benefit from regular real user monitoring. Providing insight into the service latency to help developers identify poorly performing code. Want to learn more?

Monitoring 176

Monitoring Latency Mobile Best Practices 176

Tech News Gather

FEBRUARY 20, 2023

With some unique advantages like low latency and faster speed, 5G aims to give birth to a new era of mobile application development with some innovations. With the increase in speed and less latency, there are a lot of possibilities that can be explored in the field of the internet of things (IOT) and smart devices.

Mobile 40

Mobile Development Artificial Intelligence IoT 40

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

IO River

NOVEMBER 2, 2023

This type of traffic originates directly from the server, making it more challenging to handle due to latency and server load considerations; it’s hard but not impossible. Statistics reveal that a 1% improvement in latency can lead to a 3% increase in viewer engagement, highlighting its significance in live content delivery.3.

Architecture 52

Architecture Performance Internet Internet 52

IO River

NOVEMBER 2, 2023

This type of traffic originates directly from the server, making it more challenging to handle due to latency and server load considerations; it’s hard but not impossible. Statistics reveal that a 1% improvement in latency can lead to a 3% increase in viewer engagement, highlighting its significance in live content delivery.3.

Architecture 52

Architecture Performance Internet Internet 52

All Things Distributed

OCTOBER 25, 2013

In the back to basics readings this week I am re-reading a paper from 1995 about the work that I did together with Thorsten on solving the problem of end-to-end low-latency communication on high-speed networks. The lack of low-latency made that distributed systems (e.g.

Network 96

Network Latency Operating System Speed 96

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

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. The governor "powersave" may decide which speed to use within this range.

Benchmarking 63

Benchmarking Performance Hardware C++ 63

SQL Performance

APRIL 27, 2020

Fast forward a few years after Azure SQL Database was released to when Azure SQL Managed Instance was in public preview, and "vCores" (virtual cores) were announced for Azure SQL Database. Overall, the 72 vCore size can provide more CPU performance than the 80 vCore Gen 5 by providing a lower CPU latency and higher clock speeds.

Azure 55

Azure Database Serverless Hardware 55

Alex Russell

MAY 9, 2022

This is a complex topic, but to borrow from a recent post , web performance expands access to information and services by reducing latency and variance across interactions in a session, with a particular focus on the tail of the distribution (P75+). Consistent performance matters just as much as low average latency.

Performance 86

Performance Latency Metrics Engineering 86

HammerDB

MAY 5, 2019

However in the Skylake microarchitecture (you can see a list of CPUs here ) the PAUSE instruction changed and in the documentation it says “the latency of the PAUSE instruction in prior generation microarchitectures is about 10 cycles, whereas in Skylake microarchitecture it has been extended to as many as 140 cycles.”

Testing 48

Testing Tuning Latency Storage 48

ScaleOut Software

JULY 19, 2021

Hosted on a cluster of physical or virtual servers, it maintains memory-based state information about the history and dynamically evolving state of every data source. In-memory computing has the speed and scalability needed to generate responses within milliseconds, and it can evaluate and report aggregate trends every few seconds.

IoT 78

IoT Analytics Big Data Architecture 78

VoltDB

JUNE 1, 2017

It was – like the hypothetical movie I describe above – more than a little bit odd, as you could leave a session discussing ever more abstract layers of virtualization and walk into one where they emphasized the critical importance of pinning a network interface to a specific VM for optimal performance.

Hardware 56

Hardware Latency Virtualization Cloud 56

Testsigma

AUGUST 24, 2020

Maintaining test data in a central repository and then accessing it from different test environments may ease this problem but may introduce other issues like network latency in tests. Leveraging Cloud-based Virtual Infrastructure: Cloud-based test environments can be made accessible instantaneously on demand.

Testing 69

Testing Open Source Scalability Latency 69

Speed Curve

DECEMBER 4, 2023

Not to belabor the point, but FID paints quite a different story, with virtually all (99.9%) desktop sites and 93.6% Latency is traditionally worse on mobile Despite improved network conditions in some parts of the world, round trip time is still much worse for mobile than desktop. for desktop, but only 64.9% for mobile.

Mobile 54

Mobile Performance Metrics Google 54

VoltDB

JULY 10, 2018

In these scenarios, having the system as a monolithic one inhibits the development team from being able to move forward at speed. In these use cases, data processing usually has less than a 5 milliseconds latency budget. As the complexity of applications and systems increases, the size of the teams that work on these also increase.

Architecture 40

Architecture Scalability Ecommerce Latency 40

VoltDB

JULY 10, 2018

In these scenarios, having the system as a monolithic one inhibits the development team from being able to move forward at speed. In these use cases, data processing usually has less than a 5 milliseconds latency budget. As the complexity of applications and systems increases, the size of the teams that work on these also increase.

Architecture 40

Architecture Scalability Ecommerce Latency 40

Adrian Cockcroft

NOVEMBER 18, 2019

OPN304 Learnings from migrating a service from JDK 8 to JDK 11 AWS Lambda improved latency by migrating to JDK 11 with Amazon Corretto. OPN402 Firecracker open-source innovation Since Firecracker’s release at re:Invent 2018, several open-source teams have built on it, while AWS has continued investing in Firecracker’s speed.

Open Source 40

Open Source AWS Lambda Serverless 40

Adrian Cockcroft

NOVEMBER 18, 2019

OPN304 Learnings from migrating a service from JDK 8 to JDK 11 AWS Lambda improved latency by migrating to JDK 11 with Amazon Corretto. OPN402 Firecracker open-source innovation Since Firecracker’s release at re:Invent 2018, several open-source teams have built on it, while AWS has continued investing in Firecracker’s speed.

Open Source 40

Open Source AWS Lambda Serverless 40

The Morning Paper

APRIL 14, 2019

Microarchitectural timing channels result from competition for hardware resources that are functionally transparent to software… the [ISA] abstraction leaks, as it affects observable execution speed, leading to timing channels. Even when we do flush caches, the latency of flushing can itself be used as a channel!

Hardware 44

Hardware Cache Latency Speed 44

VoltDB

JUNE 1, 2017

It was – like the hypothetical movie I describe above – more than a little bit odd, as you could leave a session discussing ever more abstract layers of virtualization and walk into one where they emphasized the critical importance of pinning a network interface to a specific VM for optimal performance.

Hardware 40

Hardware Latency Virtualization Cloud 40

O'Reilly

DECEMBER 2, 2019

High-speed networks through 5G may represent the next generation of cord cutting. Rural connectivity is a persistent problem; many rural users (and some urban users) are still limited to dial-up speeds. There are impressive estimates for latency for 5G, but reality has a tendency to be harsh on such predictions. I don’t, do you?

Wireless 53

Wireless Serverless IoT Artificial Intelligence 53

Brendan Gregg

AUGUST 8, 2017

Anyway, the following patch seems to make the load average much more consistent WRT the subjective speed of the system. rc5-virtual (bgregg-xenial-bpf-i-0b7296777a2585be1) 08/01/2017 _x86_64_ (8 CPU) 10:15:51 PM UID PID %usr %system %guest %CPU CPU Command 10:16:51 PM 0 18468 2.85 Latency was acceptable and no one complained.

Latency 111

Latency Metrics C++ Systems 111

The Netflix TechBlog

SEPTEMBER 24, 2021

Uploading and downloading data always come with a penalty, namely latency. Virtual Assembly Figure 3 describes how a virtual assembly of the encoded chunks replaces the physical assembly used in our previous architecture. In order to do that, the storage cloud object is modeled as a number of fixed size parts.

Cloud 237

Cloud Media Storage Cache 237

Smashing Magazine

JANUARY 11, 2021

You need a business stakeholder buy-in, and to get it, you need to establish a case study, or a proof of concept using the Performance API on how speed benefits metrics and Key Performance Indicators ( KPIs ) they care about. Note : If you use Page Speed Insights or Page Speed Insights API (no, it isn’t deprecated!),

Performance 145

Performance Cache Media Metrics 145

HammerDB

OCTOBER 12, 2018

maximum transition latency: Cannot determine or is not supported. . GHz. The governor "performance" may decide which speed to use within this range. Error in Virtual User 1: mysqlexec/db server: Table 'mysql.proc' doesn't exist. Vuser 1:56 Active Virtual Users configured.

Best Practices 40

Best Practices Scalability Performance C++ 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. Both Xen and KVM have had many performance and security improvements, and workloads can now be tuned to run at almost bare metal speeds (say, a 3% loss or less). Hit Ctrl-C to end. ^C

Virtualization 76

Virtualization AWS Engineering Hardware 76