This is a new spin on dependency-based attacks that has interesting implications for reliability.

  Christoph Treude — The Conversation

In a counterpoint to the articles I linked to last week, this engineer expects that the Twitter infrastructure will keep trucking on for awhile due to automation and redundancy.

  Rory Bathgate — ITPro

When folks use blaming language, bring up counterfactuals, or exhibit other suboptimal behaviors in a retrospective, what’s a good way to respond, and what doesn’t work as well?

  Fred Hebert

Cloudflare uses a novel approach to make the most out of a limited number of IPv4 addresses for outgoing traffic: “soft-unicast”.

  Marek Majkowski — Cloudflare

After attending my first retrospective at Honeycomb, I wrote this article about how they establish expectations and shared context at the start of the meeting.

  Lex Neva — Honeycomb

Pilot incapacitation, an argument, and a broader rift between cohorts of pilots were just some of the many contributing factors in this air accident. In response to this 1972 accident, the UK mandated cockpit voice recorders on all commercial flights.

  Admiral Cloudberg

Here’s a good intro to creating SLOs including a section on best practices.

  Cortex

When they started to get complaints from customers, they knew it was time to get serious about measuring and monitoring their reliability.

  arun — Reputation

As an SRE and sysadmin with 10+ years of industry experience, I wanted to write up a few scenarios that are real threats to the integrity of the bird site over the coming weeks.

What follows is a thread with tens of realistic failure scenarios, many of which apply not just to Twitter.

  @MosquitoCapital on Twitter

A few amusing anecdotes reveal deeper lessons in SRE.

  David Cassel — The New Stack

A resilient system like Twitter isn’t likely to go down instantly just because of a few changes. It’s much more likely to slowly degrade, per this article.

  Christopher Carbone — Daily Mail

It’s really interesting to see where this write-up differs from a video summary of the same accident by Mentour Pilot. Given the differences, I wonder if there are even more details that both left out?

  Admiral Cloudberg

This is a really great description of common ground breakdown, referencing Woods and Klein.

  Dan Slimmon

Check it out, a conference from the Learning From Incidents people!

Echoing Bainbridge’s Ironies of Automation, this article discusses the potential dangers of over-automation, using an air accident as a case study. I hadn’t been aware of the term “Children of the Magenta” before.

   Katie Mingle — 99% Invisible

There’s more to it than just hacking together some slack workflows.

   Ryan McDonald — FireHydrant

Honeycomb doesn’t do its SLOs “by the book”.

The way Honeycomb defines SLOs is radically different from what I expected. Instead of the definitions I wrote about at the beginning of this post, I saw:

  Reid Savage — Honeycomb
  Full disclosure: Honeycomb is my employer.

An anonymous Twitter engineer talks about what’s going on over there and how they think it might play out.

  Chris Stokel-Walker — MIT Technology Review

They rolled out automated rollbacks across a complex infrastructure, and in this article, they share the lessons they learned in the process.

  Will Sewell and Joseph Pallamidessi — Monzo

Okay. Here’s the Important Thing:

As you approach maximum throughput, average queue size – and therefore average wait time – approaches infinity.

  Dan Slimmon

It was not clear to the pilots that the fuel estimation system was not designed to be used in the way they were using it.

  Admiral Cloudberg

As is usually the case with air accidents, the crash of Air Florida flight 90 did not have a single cause. In fact, the accident was the result of the confluence of two proximate factors, each of which was itself the culmination of a long chain of errors.

  Admiral Cloudberg

The theme of this article is, somebody knows. So often this is the case with lurking infrastructure issues, and it only becomes clear that somebody knew about the underlying risk once things blow up (or never). How can we find out these things that someone already knows, soon enough to act?

  Elizabeth Ayer

In this air crash investigation report, somebody knew: the maintenance supervisor had written multiple memos about a risky maintenance practice to no avail, and the practice directly contributed to the crash.

  Admiral Cloudberg

And in this one, somebody knew too: a trained pilot in a nearby village called air traffic control to warn them that a plane looked likely to crash into a mountain and needed to pull up — shortly before it hit the mountain.

  Admiral Cloudberg

A lolsob-worthy comment on laying off SREs. And here‘s a totally on-point reply with the somebody knew moment.

Partly, it’s about accepting that this is hard work. The other part is choosing where your energy input can yield the most learning.

Full disclosure: Fred is my teammate at work.

  Fred Hebert

Check it out, the incident.io folks started a podcast about incidents!

  incident.io

Here’s Google’s report for a BigQuery outage that occurred on October 13.

  Google

At last9, we auto-delete slack messages after 2 days on all personal Direct Messages. These retention policies force teams to improve documentation, kill tribal knowledge and drive accountability for mistakes, errors.

  Nishant Modak — Last9

There are some interesting tidbits in the pile of incidents in this report.

  Jakub Oleksy — GitHub

Don’t beat yourself up! This is like another form of blamelessness.

  Robert Ross — FireHydrant + The New Stack

In this article, I will share with you how setting up passive guardrails in and around developer workflows can reduce the frequency and severity of incidents and outages.

  Ash Patel — SREPath

This conference talk summary outlines the three main lessons Jason Cox learned as director of SRE at Disney.

  Shaaron A Alvares — InfoQ

Here’s a look at how Meta has structured its Production Engineer role, their name for SREs.

  Jason Kalich — Meta

Bit-flips caused by cosmic rays seem incredibly rare, but they become more likely as we make circuits smaller and our infrastructures larger.

  Chris Baraniuk — BBC

Cloudflare shares details about their 87-minute partial outage this past Tuesday.

  John Graham-Cumming — Cloudflare

In reaction to a major outage, these folks revamped their alerting and incident response systems. Here’s what they changed.

  Vivek Aggarwal — Razorpay

The author of this post sought to test a simple algorithm from a research paper that purported to reduce tail latency. Yay for independent verfication!

  Marc Brooker