My understanding, paraphrased: "In order to gradually roll out one change, we had to globally push a different configuration change, which broke everything at once".

But a more important takeaway:

> This type of code error is prevented by languages with strong type systems

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jsnell 3 hours ago | parent | next [-]

That's a bizarre takeaway for them to suggest, when they had exactly the same kind of bug with Rust like three weeks ago. (In both cases they had code implicitly expecting results to be available. When the results weren't available, they terminated processing of the request with an exception-like mechanism. And then they had the upstream services fail closed, despite the failing requests being to optional sidecars rather than on the critical query path.)

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pdimitar an hour ago | parent | next [-]

To be precise, the previous problem with Rust was because somebody copped out and used a temporary escape hatch function that absolutely has no place in production code.

It was mostly an amateur mistake. Not Rust's fault. Rust could never gain adoption if it didn't have a few escape hatches.

"Damned if they do, damned if they don't" kind of situation.

There are even lints for the usage of the `unwrap` and `expect` functions.

As the other sibling comment points out, the previous Cloudflare problem was an acute and extensive organizational failure.

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littlestymaar 3 hours ago | parent | prev [-]

In fairness, the previous bug (with the Rust unwrap) should never have happened: someone explicitly called the panicking function, the review didn't catch it and the CI didn't catch it.

It required a significant organizational failure to happen. These happen but they ought to be rarer than your average bug (unless your organization is fundamentally malfunctioning, that is)

	▲	greatgib 2 hours ago \| parent [-]
		The issue would also not have happened, if someone did the right code, tests, and the review or CI caught it...

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debugnik 3 hours ago | parent | prev | next [-]

Prevented unless they assert the wrong invariant at runtime like they did last time.

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skywhopper 3 hours ago | parent | prev [-]

This is the exact same type of error that happened in their Rust code last time. Strong type systems don’t protect you from lazy programming.