Hacker News Reader

Comment by gberger | Hacker News Reader

> I'm not sure that 55 months of up-time indicates it's more or less likely to go down in the next month, but I'd guess more likely.

If 'going down' is an event governed by chance (e.g. power failure), then it does not matter if it has been up for 55 months or 55 minutes.

https://en.wikipedia.org/wiki/Gambler%27s_fallacy

View on HN

There’s also the Turkey fallacy - Turkeys that are smug about knowing the Gambler’s fallacy keep thinking their survival is independent of their age, until people eat them. My probability of dying goes up with each year as well, it’s not constant.

Think the probability of the machine shutting down in the next minute is independent of age, but it shutting off in the next 100 years is certain. There’s a line or curve that should indicate probability of shutting down before OP writes the replacement.

This is how I feel when people talk about Schroedingers cat. Give me a week and I'll be able to answer that question definitively.

Gambler's Fallacy is applicable "when it has otherwise been established that the probability of such events does not depend on what has happened in the past" -- not the case here.

The fact that the server has been running uninterrupted for 55 months is a strong clue that the power to this system is robust, not subject to "random" power loss scenarios like one would expect at a typical residence.

> The fact that the server has been running uninterrupted for 55 months is a strong clue that the power to this system is robust, not subject to "random" power loss scenarios like one would expect at a typical residence.

I don't remember random power losses in typical first world residences after perhaps the 1990s?

I get them at my house. Every time there's an ice storm. And for a while there was an intermittent issue where floodwaters came up over my internet port in the junction box, and so my internet would go out for a while. Hopefully the power grid isn't as janky.

Interesting! I guess I never lived either in rural areas or anywhere with ice storms.

It depends on what kind of chance we are talking about.

See eg https://en.wikipedia.org/wiki/Bathtub_curve for a common way to fail. Or https://en.wikipedia.org/wiki/Reliability_engineering in general.

You are right about some specific kinds of spontaneous failures. (Though not sure if external power failures are distributed that way.)

Reply on news.ycombinator.com