Links list - 2022-07-10

Hello, and welcome to a new edition of Links lists! A few longer but interesting articles this week, and a couple of short ones. I hope you enjoy them!

Tech article

Swapping memory at Meta

Swapping unused memory to the disk, to fit more applications in RAM, is a simple concept that all developers (I hope!) are familiar with. This article from FacebookMeta explains how they have built an infrastructure, composed of a kernel module and a userspace agent, to more aggressively implement swapping while measuring application impact, for self-tuning.

The results seem great: 20-30% memory saving with very low applications impact, which means being able to fit more applications on servers - a significant money-saving, at their scale. Pretty in-depth article, and very interesting.

Transparent memory offloading: more memory at a fraction of the cost and power

-Transparent memory offloading (TMO) is Meta’s data center solution for offering more memory at a fraction of the cost and power of existing technologies -In production since 2021, TMO saves 20 percent to 32 percent of memory per server across millions of servers in our data center fleet We are witn…

Johannes Weiner · Engineering at Meta

The tension between standardization and exploration

In every tech company, there is a tension between standardizing tools and allowing your engineers some freedom to explore. On one hand, you cannot build each and every application from scratch with some obscure programming language or framework, because that would be a maintenance nightmare. But, you also cannot simply reuse the same things for ages without ever innovating, because the tech world moves so fast and you will fall behind - not to mention, lose great people that just get bored.

This article is an interesting point of view about this theme - I don't agree with everything within it, but it is a reasonable and well-argued point of view.

Magnitudes of exploration.

Standardizing on a given platform or technology is one of the most powerful ways to create leverage within a company: improve the tooling a bit and every engineer will get more productive. Exploration is, in the long run, an even more powerful force, with successes compounding over time. Developing…

lethain.com

CORS

If you do not know what CORS is, or how it can be exploited, this is a pretty good guide in my opinion, written from a security expert point of view. Note: the link is to a PDF file.

cors-security-guide

bedefended.com

Various kinds of UUID

You probably have used UUIDs before, but did you know there are multiple families of them, and how do they work? This is a very clear and concise explanation.

A Complete Guide to UUID Versions (v1, v4, v5) - With Examples

This post will describe UUID v1, v4, and v5, with examples. We will go through their implementation and differences, and when you should use them

Soham Kamani · sohamkamani.com

A trick of the tail

Did you know that tail can be used in reverse order with -r? I did not, pretty useful!

Tail I lose

I just learned how the tail command really works.

leancrew.com

Non tech

History of glass

An interesting story of glass making, with some fantastic pictures, and its importance in leading to the scientific revolution - which the article probably overstates a bit.

A Clear History of Glass

I’ve written about glass, as in lenses, for years now. But I’ve never looked into the history of glass as just a substance, because, well, who cared? When I accidentally did some reading about early glass, though, I was rather amazed at just how important it was. So I thought I’d write about the his…

Roger Cicala · Lensrentals Blog