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

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

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

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. For example, you can think of a cell phone network as a type of distributed system, consisting of a network of internet-connected devices that share resources workload. Peer-to-Peer.

Systems 74

Systems Monitoring Hardware Network 74

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. The odd time we hit them, we'll take the "oops message" – a dump of the kernel stack trace and other details from the system log – and search the Internet.

Virtualization 76

Virtualization AWS Engineering Hardware 76

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