It's great that you're working on regionalization. Yes, it is hard, but 100x harder if you don't start with cellular design in mind. And as I said in the root of the thread, this is a sign that CloudFlare needs to invest in it just like you have been.
I recoil from that last statement not because I have a rooting interest in Cloudflare but because the last several years of working at Fly.io have drilled Richard Cook's "How Complex Systems Fail"† deep into my brain, and what you said runs aground of Cook #18: Failure free operations require experience with failure.
If the exact same thing happens again at Cloudflare, they'll be fair game. But right now I feel people on this thread are doing exactly, precisely, surgically and specifically the thing Richard Cook and the Cook-ites try to get people not to do, which is to see complex system failures as predictable faults with root causes, rather than as part of the process of creating resilient systems.
Suppose they did have the cellular architecture today, but every other fact was identical. They'd still have suffered the failure! But it would have been contained, and the damage would have been far less.
Fires happen every day. Smoke alarms go off, firefighters get called in, incident response is exercised, and lessons from the situation are learned (with resulting updates to the fire and building codes).
Yet even though this happens, entire cities almost never burn down anymore. And we want to keep it that way.
As Cook points out, "Safety is a characteristic of systems and not of their components."
What variant of cellular architecture are you referring to? Can you give me a link or few? I'm fascinated by it and I've led a team to break up a monolithic solution running on AWS to a cellular architecture. The results were good, but not magic. The process of learning from failures did not stop, but it did change (for the better).
No matter what architecture, processes, software, frameworks, and systems you use, or how exhaustively you plan and test for every failure mode, you cannot 100% predict every scenario and claim "cellular architecture fixes this". This includes making 100% of all failures "contained". Not realistic.
If your AWS service is properly regionalized, that’s the minimum amount of cellular architecture required. Did your service ever fail in multiple regions simultaneously?
Cellular architecture within a region is the next level and is more difficult, but is achievable if you adhere to the same principles that prohibit inter-regional coupling:
It wasn't worth thinking about. I'm not going to defend myself against arguments and absolute claims I didn't make. The key word here is mitigation, not perfection.
> If your AWS service is properly regionalized, that’s the minimum amount of cellular architecture required
Amazon has had multi-region outages due to pushing bad configs, so it’s extremely difficult to believe whatever you are proposing solves that exact problem by relying on multi-regions.
Come to think of it, Cloudflare’s outage today is another good counterexample.
It has been a very, very long time since AWS had a simultaneous failure across multiple regions. Even customers impacted by the loss of Route 53 control plane functionality in last month’s us-east-1 were able to gracefully fail over to a backup region if they configured failover records in advance, had Application Recovery Controller set up, or fronted their APIs or websites with Global Accelerator.
Customers survive incidents on a daily basis by failing over across regions (even in the absence of an AWS regional failure, they can fail due to a bad deployment or other cause). The reason you don’t hear about it is because it works.
Thank you for saying it. I’m getting exasperated at how many people in the comments are making some variant of the “lazy programmer wrote code that took a shortcut” argument.
Complex system failures are not monocausal! Complex systems are in a continuous state of partial failure!
https://fly.io/blog/corrosion/