SRE Weekly Issue #282

A message from our sponsor, StackHawk:

ICYMI ZAP Creator and Project Lead Simon Bennetts recently unveiled ZAP’s new automation framework. Watch the session and see how it works:
https://sthwk.com/Automation-Framework

Articles

I really need to learn bpftrace, and this article is a great place to start.

Brendan Gregg

If we expand our definition of “incident” beyond traditional engineering problems, we increase our opportunity for learning.

Stephen Whitworth — incident.io

This is an interview with a director at Catchpoint about their 2021 SRE Report. They discuss two results from the survey: folks report a 15% decrease in toil and slow adoption of AIOps.

Charlene O’Hanlon — devops.com

A recurring theme in this story is that the incident was when folks learned how the push notifications work.

Molly Struve — DEV

In this reddit thread, a company hired some developers as SREs and then found that they didn’t want to do operations work. Folks weigh on why and what to do.

u/red_flock and others — reddit

How exactly do you want to phrase (and measure) an SLO about latency percentiles? Beware the subtle details.

Piyush Verma — last9

I’m definitely going to think on the great incident response and followup wisdom in this interview. My favorite:

If I can change 1% to better that outcome, what is that 1%?

Christina Tan — Blameless

Full disclosure: Fastly, my employer, is mentioned.

Root cause: guessed wrong in the moment

Lorin Hochstein

Here’s a run-down of some IT mishaps from Olympic games past and present.

Quentin Rousseau — Rootly

Outages

SRE Weekly Issue #281

A message from our sponsor, StackHawk:

Traditional application security testing methods fail for single page applications. Check out why single page apps are different and how you can run security tests on your SPAs.
https://sthwk.com/SPA

Articles

The incident: a formula 1 car hit the side barrier just over 20 minutes before the race was about to start. The team sprang into action with an incredibly calm, orderly and speedy incident response to replace the damaged parts faster than they ever have before.

This article is a great analysis, and there’s also an excellent 8-minute video that I highly recommend. Listen to the way the sporting director and everyone else communicates so calmly. It’s a rare treat to get video footage of a production incident like this.

Chris Evans — incident.io

The underlying components become the cattle, and the services become the new Pet that you tend to with your utmost care.

Piyush Verma — Last9

AWS posted these example/template incident response playbooks for customers to use in their incident response process.

Aws

A list with descriptions of all DNS record types, even the obscure ones. Tag yourself, I’m HIP.

Jan Schaumann

This one includes a useful set of questions to prompt you as you develop your incident response and classification process.

Hollie Whitehead — xMatters

The author of this article shows us how they communicate actively, perform incident retrospectives, and even discuss “near misses” and normal work in order to better learn how their system works — all skills that apply directly to SRE.

Jason Koppe — Learning From Incidents

Although the fundamental concepts of site reliability engineering are the same in any environment, SREs must adapt practices to different technologies, like microservices.

JJ Tang — Rootly

This one uses Akamai’s incident report from their July 22 major outage as a jumping-off point to discuss openness in incident reports. The text of Akamai’s incident report is included in full.

Geoff Huston — CircleID

Drawing from the “normalization of deviance” concept introduced in the Challenger disaster study [Diane Vaughan], this article explores the idea of studying your organization culture to catch problems early, rather than waiting to respond after they happen.

Stephen Scott

This episode of the StaffEng Podcast is an interview with Lorin Hochstein, whose writings I’ve featured here numerous times. My favorite part of this episode is when they talk about doing incident analysis for near misses. One of the hosts points out that it’s much easier for folks to talk about what happened, because there was no incident so they’re not worried about being blamed.

David Noël-Romas and Alex Kessinger– StaffEng Podcast

Outages

SRE Weekly Issue #280

A message from our sponsor, StackHawk:

DataRobot is using StackHawk to automate API security testing and to scale AppSec across their dev team. Learn more about all they’re up to:
https://sthwk.com/DataRobot

Articles

The Robustness Principle (“be conservative in what you send, and liberal in what you accept”) has its uses, but it may not be best for the development of mature protocols, according to this IETF draft.

Martin Thomson

Docker without Kubernetes, does it make sense? These folks have a well-reasoned argument explaining why Kubernetes is not for them.

Maik Zumstrull — Ably

Can a service outage unrelated to security count as a “personal data breach” in terms of GDPR and other regulations? If you agree with this article’s logic, then maybe it can.

Neil Brown

The interactions between security and reliability incidents can be complex and hard to navigate. The example scenarios in this article really made me think.

Quentin Rousseau — Rootly

To deal with thundering herds, reddit implements caching in front of each of its microservices.

Raj Shah — reddit

Incident causes are a social construct, and it may be that your organizational structure prevents something from being counted as a cause.

Lorin Hochstein

Check it out, Dropbox publicly released their SRE career ladder.

Dropbox

There’s a moment halfway through this episode of Page It to the Limit where they talk about blamelessness. If you just tell people to “do blameless postmortems”, but you don’t tell them how, then they’ll be afraid to talk about anything people did, and that will hamper learning.

Julie Gunderson, with guestTim Nicholas — Page It to the Limit

This was a monumental task, considering the 1000+(!!) internal code patches they had to port from MySQL 5.6 to 8.0.

Herman Lee, Pradeep Nayak — Facebook

Outages

SRE Weekly Issue #279

A message from our sponsor, StackHawk:

On July 28, ZAP Creator Simon Bennetts is giving a first look at ZAP’s new automation framework. Grab your spot:
https://sthwk.com/ZAP-Automation

Articles

This is a presentation by Laura Nolan (with text transcript) all about cascading failure, what causes it, how to avoid it, and how to deal with it when it happens.

I love how succinct this is:

[…] in any system where we design to fail over, so any mechanism at all that redistributes load from a failed component to still working components, we create the potential for a cascading failure to happen.

Laura Nolan — Slack (presented at InfoQ)

It’s so easy to explain an incident by describing how management could have prevented it from investing additional resources.

Lorin goes on to explain the “trap” part: it’s easy to stop investigating an incident too soon and declare the cause “greedy executives”, preventing us from learning more.

Lorin Hochstein

They redesigned one of their caching systems in 2020, and it paid off handsomely during the GameStop saga. This article discusses the redesign and considers what would have happened without it.

Garrett Hoffman — Reddit

The lessons are:

  1. Do retrospectives for small incidents first.
  2. Do a retrospective soon after the incident.
  3. Alert on the user experience.

All great advice, and #1 is an interesting idea I hadn’t heard before.

Robert Ross — FireHydrant

We can’t engineer reliability in a vacuum. This is a great explainer on how SRE siloing happens, the problems it causes, and how to break SRE out of its shell.

JJ Tang — Rootly

This ASRS (Aviation Safety Reporting System) Callback issue has some real-world examples of resilient systems in action.

Nasa Asrs

Facing a common kubernetes node failure modes, Cloudflare uses open source tools (one published by them) to perform automatic restarts.

In the past 30 days, we’ve used the above automatic node remediation process to action 571 nodes. That has saved our humans a considerable amount of time.

Andrew DeMaria — Cloudflare

Outages

SRE Weekly Issue #278

A message from our sponsor, StackHawk:

Learn how our team at StackHawk tests external cookie authentication using Ktor, and check out some of the helper functions we wrote to make the tests easy to write, read, and maintain
https://sthwk.com/ktor

Articles

Whoa.  This is the best thing ever.  I feel like I want to make this the official theme song of SRE Weekly.

Forrest Brazeal

Their auto-scaling algorithm needed a tweak. Before: scale up by N instances. After: scale up by an amount proportional to the current number of instances.

Fran Garcia — Reddit

here’s a look at incidents and reliability challenges that have occurred in outer space, and what SREs stand to learn from them.

JJ Tang — Rootly

This one includes 3 key things to remember while load testing. My favorite: test the whole system, not just parts.

Cortex

SRE is as much about building consensus and earning buy-in as it is about actual engineering.

Cortex

The definition of NoOps in this article is more clear than others I’ve seen. It’s not about firing your operations team — their skill set is still necessary.

Kentaro Wakayama

Even though I know what observability is, I got a lot out of this article. It has some excellent examples of questions that are hard to answer with traditional dashboards, and includes my new favorite term:

The industrial term for this problem is Watermelon Metrics; A situation where individual dashboards look green, but the overall performance is broken and red inside.

Nishant Modak and Piyush Verma — Last9

Instead, we should consider the fields there where practitioners are responsible for controlling a dynamic process that’s too complex for humans to fully understand.

Lorin Hochstein

In this epic troubleshooting story, a weird curl bug coupled with Linux memory tuning parameters led to unexpected CPU consumption in an unrelated process.

Pavlos Parissis — Booking.com

Learning a lesson from a rough Black Friday in 2019, these folks used load testing to gather hard data on how they would likely fare in 2020.

Mathieu Garstecki — Back Market

Outages

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