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. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI.

Speed 126

Speed Java AWS Virtualization 126

The Morning Paper

DECEMBER 10, 2019

This is a companion paper to the " persistent problem " piece that we looked at earlier this week, going a little deeper into the object pointer representation choices and the mapping of a virtual object space into physical address spaces. Both abstractions must be implemented in a way that is efficient using existing hardware.

Hardware 52

Hardware Virtualization Operating System Programming 52

All Things Distributed

MARCH 11, 2016

Almost from day one, we knew that the software we were building would not be the software that would be running a year later. We needed to build such an architecture that we could introduce new software components without taking the service down. Build evolvable systems. Primitives not frameworks. Automation is key.

AWS 144

AWS Hardware Retail Virtualization 144

Dotcom-Montior

NOVEMBER 24, 2021

These systems can include physical servers, containers, virtual machines, or even a device, or node, that connects and communicates with the network. A three-tier system is a software application architecture that consists of a presentation layer, application layer, and data, or core, layer. Blockchain is a good example of this.

Systems 74

Systems Monitoring Hardware Network 74

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. hardware limits: 1000 MHz - 4.00 hardware limits: 1000 MHz - 4.00

Benchmarking 63

Benchmarking Performance Hardware C++ 63

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

This was a chance to talk about other things I've been working on, such as the present and future of hardware performance. The video is on [youtube]: The slides are [here] or as a [PDF]: first prev next last / permalink/zoom I work on many areas of performance, but recently I've had a lot of demand to talk about BPF. Ford, et al., “TCP

Performance 52

Performance Latency Hardware Storage 52

Brendan Gregg

AUGUST 18, 2019

bpftrace is a new open source tracer for Linux for analyzing production performance problems and troubleshooting software. For example, iostat(1), or a monitoring agent, may tell you your average disk latency, but not the distribution of this latency. software Kernel software-based events.

Latency 68

Latency C++ Cache Programming 68

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

HammerDB

OCTOBER 23, 2023

The data shows a scripted automated workload running a number of back to back tests each time with an increasing number of virtual users. Using MariaDB and analysing performance at a workload of 80 Virtual Users the first place we can look at is the information schema user_statistics to quantify the difference in the database traffic.

Benchmarking 62

Benchmarking Database Network C++ 62

The Morning Paper

APRIL 14, 2019

The paper sets out what we can do in software given today’s hardware, and along the way also highlights areas where cooperation from hardware will be needed in the future. Even when we do flush caches, the latency of flushing can itself be used as a channel! Microarchitectural channels. Threat scenarios.

Hardware 44

Hardware Cache Latency Speed 44

The Morning Paper

DECEMBER 8, 2019

Byte-addressable non-volatile memory,) NVM will fundamentally change the way hardware interacts, the way operating systems are designed, and the way applications operate on data. Therefore any programming abstraction must be low latency and the kernel needs to be kept off the path of persistent data access as much as possible.

Hardware 56

Hardware Programming Media Storage 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. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI.

Speed 52

Speed Java AWS Virtualization 52

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

All Things Distributed

JANUARY 23, 2012

The Amazon Virtual Private Cloud extends on-premises compute with all the power of AWS, making it elastic, scalable and highly reliable. The AWS Storage Gateway is a service connecting an on-premises software appliance with cloud-based storage. s storage infrastructure. Once the AWS Storage Gatewayâ??s

Storage 115

Storage AWS Virtualization Cloud 115

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. As a Xen guest, this profile was gathered using perf(1) and the kernel's software cpu-clock soft interrupts, not the hardware NMI.

Speed 40

Speed Java AWS Virtualization 40

Dotcom-Montior

DECEMBER 8, 2021

You cannot virtualize everything…yet. Software services still require physical devices and hardware for them to function. Knowing when and where an error, downtime, or application latency occurs is a critical factor in limiting the impact to users and customers. Asset Management.

Social Media 90

Social Media Monitoring Latency DevOps 90

Abhishek Tiwari

JULY 12, 2018

Data Pipeline A data pipeline is a software that ingests data from multiple sources, transforms it and finally makes it available to internal or external products. A data pipeline is a software which runs on hardware. The software is error-prone and hardware failures are inevitable.

Latency 63

Latency Analytics Scalability Engineering 63

HammerDB

DECEMBER 5, 2020

A full understanding of why this is important requires some knowledge of the evolution of database hardware and software. For TPC-C this meant enough available spindles to reduce I/O latency and for TPC-H enough bandwidth for data throughput. This was both expensive and time consuming to configure.

C++ 40

C++ Benchmarking Virtualization Open Source 40

All Things Distributed

JANUARY 18, 2012

Amazon DynamoDB offers low, predictable latencies at any scale. This is not just predictability of median performance and latency, but also at the end of the distribution (the 99.9th percentile), so we could provide acceptable performance for virtually every customer. s read latency, particularly as dataset sizes grow.

Scalability 167

Scalability Database Ecommerce Latency 167

Percona

APRIL 17, 2023

Operating System (OS) settings Swappiness Swappiness is a Linux kernel setting that influences the behavior of the Virtual Memory manager when it needs to allocate a swap, ranging from 0-100. The CFQ works well for many general use cases but lacks latency guarantees. Without further ado, let’s start with the OS settings.

Best Practices 52

Best Practices Design Tuning Database 52

HammerDB

OCTOBER 12, 2018

As is also the case this limitation is at the database level (especially the storage engine) rather than the hardware level. driver: intel_pstate CPUs which run at the same hardware frequency: 0 . CPUs which need to have their frequency coordinated by software: 0 . hardware limits: 1000 MHz - 3.80

Best Practices 40

Best Practices Scalability Performance C++ 40

Alex Russell

APRIL 29, 2021

Now in development in WebKit after years of radio silence, WebXR APIs provide Augmented Reality and Virtual Reality input and scene information to web applications. For heavily latency-sensitive use-cases like WebXR, this is a critical component in delivering a good experience. is access to hardware devices. Offscreen Canvas.

Media 145

Media Games Education Engineering 145

Brendan Gregg

AUGUST 8, 2017

I generated this using my offcputime tool from [bcc] (this tool needs eBPF features from Linux 4.8+), and my [flame graph] software: #./bcc/tools/offcputime.py 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 termc$ uptime.

Latency 111

Latency Metrics C++ Systems 111

Abhishek Tiwari

DECEMBER 27, 2017

Containerized data workloads running on Kubernetes offer several advantages over traditional virtual machine/bare metal based data workloads including but not limited to. direct access to raw block storage [18] without the abstraction of a filesystem for workloads that require consistent I/O performance and low latency.

Big Data 63

Big Data Storage Benchmarking Hardware 63

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

SQL Server According to Bob

JANUARY 11, 2020

Many high-end disk subsystems provide high-speed cache facilities to reduce the latency of read and write operations. Example 1: ​​ Hardware failure (CPU board) Battery backup on the caching controller maintained the data. Important Always consult with your hardware manufacturer for proper stable media strategies.

Servers 40

Servers Cache Media Hardware 40

Dynatrace

AUGUST 5, 2019

With Dynatrace, we follow a combination of agent and agent-less approach where the “secret sauce” lies in our Dynatrace OneAgent (watch my Performance Clinic YouTube tutorial with our Chief Software Architect Helmut Spiegl ). if you have a feature that relies on dedicated hardware and that users only execute once per week (e.g:

Cloud 31

Cloud Traffic Database Network 31

SQL Server According to Bob

JANUARY 11, 2020

ReadFile WriteFile ReadFileScatter WriteFileGather GetOverlappedResult ​​ For extended details on the 823 error, see ​​ Error message 823 may indicate hardware problems or system problems ​​ ( [link] i crosoft.com/default.aspx?scid=kb ​​ Contact your hardware manufacture for assistance.

Servers 40

Servers Cache Database Media 40

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