Rollback Only Runs Forward

Code reverts. The rows it wrote, the orders it sent and the machines it crashed do not.

The short version

List every place a release writes, and mark which ones reverting the deploy actually undoes; usually it is 1 of 7. Commit reversible writes first and irreversible ones last, make every step idempotent, change schema by expand, migrate, contract, and never reuse a flag name. Knight Capital's rollback moved 7 healthy servers into the broken state.

A rollback plan that lists only the code is a plan for the one layer that was never the problem.

Read the essay →

Also worth your time

The Proof Was Never the Point

Twenty-five Fields medallists just described a measurement failure that is sitting on your dashboard

▪ CONTRARIAN · 20 MIN

The Price Held. The Bill Rose.

Gemini 3.8 Flash held the headline price, uses more tokens per task, and doubles its rate on January 1

▪ AI TECH · 14 MIN

Legibility Used to Be Free

An Altair 8800 in the browser, and what it says about machines that hide everything.

▪ TECH HISTORY · 18 MIN

Hit reply if you want to argue with any of it. It reaches me, not a queue, and I answer.

Cisco

Unsubscribe in one click · Read it on the web
You confirmed this subscription at roamingpigs.com.
RoamingPigs, Inc. · c/o Cisco Caceres, 200 W Sahara Ave, Las Vegas NV 89102