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by t-writescode 1731 days ago
At a job I worked at, we had servers that were given several internal IP addresses to map to external IP addresses.

One day, one machine just ... stopped having a bunch of those IP addresses. They were just gone.

We didn't understand, troubleshot as much as we could, and eventually just gave up and went "forget it, just try restarting the machine."

It worked.

It's amazing what weird states a computer can get into that "did you try turning it off and on again?" is a very real and legitimate and helpful piece of advice.

1 comments

Bit flips from cosmic rays happen all the time. It's inevitable that they sometimes change state in deleterious ways.
Well, bit flips happen all the time, and we call that "cosmic rays". It is not obvious that bit flips from cosmic rays in the more usual sense of "cosmic rays" happen all the time.
That's actually testable and determinable from several perspetives.

- Isolate any other sources of ionising radiation.

- Check to see if prevalence increases or decreases with increased or decreased cosmic ray exposure (atitude, shielding, detected cosmic ray storms).

- Are the characteristics those of single-bit flips? (E.g., power-of-two changes to values, or similar.)

- Are the errors nott repeated for the same hardware component. (E.g., under increased cosmic-ray influence, bits flip at an increased rate, as predicted, but which bits flip is random and has no detectable pattern, as predicted.)

You end up with very strong circumstantial evidence of altered bits due to cosmic ray influence.

https://www.wnycstudios.org/podcasts/radiolab/articles/bit-f...

https://youtube.com/watch?v=AaZ_RSt0KP8

like maybe changing a key in some hashmap