Brendan Gregg

JULY 4, 2021

AWS Graviton2); for memory with the arrival of DDR5 and High Bandwidth Memory (HBM) on-processor; for storage including new uses for 3D Xpoint as a 3D NAND accelerator; for networking with the rise of QUIC and eXpress Data Path (XDP); and so on. I also wrote about these topics in detail for my recent [Systems Performance 2nd Edition] book.

Performance 52

Performance Latency Hardware Storage 52

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%. 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

Dotcom-Montior

NOVEMBER 11, 2020

those resources now belong to cloud providers, such as AWS Lambda, Google Cloud Platform, Microsoft Azure, and others. Again, the benefit being that the code within your containers or virtual machines is managed by the cloud provider. Applications that are running continuously on a dedicated server aren’t as impacted by latency issues.

Serverless 57

Serverless Monitoring Lambda Latency 57

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

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

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

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

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. What happens if processes really do try to populate all that virtual memory? Many new tools can now be written, and the main toolkit we're working on is [bcc]. Hit Ctrl-C to end. ^C

Virtualization 76

Virtualization AWS Engineering Hardware 76

Dynatrace

AUGUST 5, 2019

In this role, I am leading a global team that works closely with our strategic partners such as AWS, Microsoft, Google, Pivotal, Red Hat and others. Lift & Shift is where you basically just move physical or virtual hosts to the cloud – essentially you just run your host on somebody else’s hardware.

Cloud 31

Cloud Traffic Database Network 31

All Things Distributed

MARCH 11, 2016

The epoch of AWS is the launch of Amazon S3 on March 14, 2006, now almost 10 years ago. Given that AWS is a pioneer in building and operating these services world-wide, these lessons have been of crucial importance to our business. This is a given, whether you are using the highest quality hardware or lowest cost components.

AWS 147

AWS Hardware Retail Virtualization 147

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

All Things Distributed

JANUARY 18, 2012

Amazon DynamoDB offers low, predictable latencies at any scale. Amazon DynamoDB stores data on Solid State Drives (SSDs) and replicates it synchronously across multiple AWS Availability Zones in an AWS Region to provide built-in high availability and data durability. s read latency, particularly as dataset sizes grow.

Scalability 167

Scalability Database Ecommerce Latency 167