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. Ford, et al., “TCP

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

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. The slightly newer Intel Xeon E5-26xx v4 (Broadwell) series which was introduced in Q1 of 2016, increased that to 2400MHz. They also only have 40 PCIe 3.0 lanes per processor. Memory (GiB).

Azure 42

Azure Virtualization Storage Benchmarking 42

Brendan Gregg

SEPTEMBER 5, 2017

LTS (April 2016). I wrote about it in a previous post, [DTrace for Linux 2016]. 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. The hardest part on Linux is now done: kernel support. Hit Ctrl-C to end. ^C

Virtualization 75

Virtualization AWS Engineering Hardware 75

Alex Russell

OCTOBER 22, 2017

It simulates a link with a 400ms RTT and 400-600Kbps of throughput (plus latency variability and simulated packet loss). Simulated packet loss and variable latency, however, can make benchmarking extremely difficult and slow. Our baseline, then, should probably trade lower throughput/higher-latency for packet loss.

Performance 74

Performance Network Benchmarking Mobile 74

Alex Russell

APRIL 29, 2021

At the time of the last Confluence run, the gap had stretched to nearly 1000 APIs, doubling since 2016. Chrome has missed several APIs for 3+ years: Storage Access API. For heavily latency-sensitive use-cases like WebXR, this is a critical component in delivering a good experience. Some relatively minor additions (e.g.

Media 145

Media Games Education Engineering 145

VoltDB

AUGUST 27, 2024

Volt Active Data (Volt) is a sophisticated real-time data platform intricately designed with multiple critical components, including high-speed data processing, in-memory storage, and ACID-compliant transactions. Why Jepsen Testing? A major customer found an atomicity bug in our export system last year.

Testing 52

Testing Database Network Systems 52

CSS Wizardry

MARCH 3, 2019

If, however, there wasn’t a new file on the server, we’ll bring back a 304 header, no new file, but an entire roundtrip of latency. We can completely cut out the overhead of a roundtrip of latency. On high latency connections, this saving could be tangible. What do we mean by a mutable or immutable file? Examples and Recipes.

Cache 270

Cache Latency Strategy Servers 270

Testsigma

FEBRUARY 12, 2021

billion in 2016. By 2021, a distributed cloud would help companies physically put all services closely together, thereby addressing low-latency challenges, minimising the expense of storage and ensuring that data standards are consistent with the laws in a given geographical region. In 2021 what can we expect?

Artificial Intelligence 92

Artificial Intelligence Software Software IoT 92