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Never trust a system that seems to be working

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Re: Never trust a system that seems to be working

#191

Post by chinabot »

pengstrom wrote: post #48
Karellen wrote: post #10

One reply tweet notes "a complex system always operates in a failure state", but to find more discussion on this point it's worth noting that this is a restatement of: > "The Fundamental Failure-Mode Theorem (F.F.T.): complex systems usually operate in a failure mode." -- John Gall, General Systemantics (aka Systemantics , aka The Systems Bible ), 1977 https://en.wikipedia.org/wiki/Systemantics > Searching for "funda…

The older I get and the more systems I encounter, the more I'm convinced everything is in a state of failing. The question is only how long before it becomes noticable.

Time to market. Nothing else matters, use whatever stack/library works and whatever I can copy/paste of stackoverflow to get it to work, we can fix the problems in software as we go and we only have to support it for 2 years then we can make another.

Re: Never trust a system that seems to be working

#192

Post by MBCook »

andirk wrote: post #169
wongarsu wrote: post #157

Earlier quoted context omitted.

Are you suggesting I'm doing worse on Google Captchas because I consider pedestrian crossing lights as a form of traffic lights but Americans don't?

Best choices to pick on captcha are not what you think is pictured but what you think most people think is pictured.

I’ve never had an issue, but I’m American. So if it’s expecting American centric answers that would make perfect sense.

So many not what most people would pick, but what Americans would pick?

Re: Never trust a system that seems to be working

#193

Post by [deleted] »

Karellen wrote: post #10

One reply tweet notes "a complex system always operates in a failure state", but to find more discussion on this point it's worth noting that this is a restatement of: > "The Fundamental Failure-Mode Theorem (F.F.T.): complex systems usually operate in a failure mode." -- John Gall, General Systemantics (aka Systemantics , aka The Systems Bible ), 1977 https://en.wikipedia.org/wiki/Systemantics > Searching for "funda…

[deleted]

Re: Never trust a system that seems to be working

#194

Post by samatman »

Lukas_Skywalker wrote: post #181
usrbinenv wrote: post #147

Earlier quoted context omitted.

I guess my point is that it was still confusing. It took me a day or two to acquire a reflex. It obviously doesn't matter in the long run - you just get used to it - but I wonder why would US & Canada go a different way with regards to so many small things (think turn signals on cars being red for american cars as another example)? What would be the rationale? It's as if the western hemisphere was completely cut off…

Since this is HN, and I'm a pedant: reflexes can't be acquired, since they are not processed by the brain, but by the spinal cord, without involvement of the brain (e.g. pulling back the hand when touching a hot surface). What you're thinking of is called procedural memory, which helps you perform a task without being consciously aware of it (hitting a fast baseball, looking left/right when crossing a street).

This is quite far from being the case.

Dr. Pavlov's seminal book is generally translated as Conditioned Reflexes. Saliva in response to a bell is a reflex, and it's an acquired one.

Not falling flat on our face when we step forward is also reflexive, as is catching something thrown to us. Both are acquired through rather lengthy processes.

There are many similar examples.

Re: Never trust a system that seems to be working

#195

Post by retzkek »

outworlder wrote: post #152
kbenson wrote: post #70

Earlier quoted context omitted.

Experienced sysadmins see the occasional chatter of problems in logs and emails as the pulse of the system, the EKG hooked up to the patient letting you know how things are going. The right level of logging is usually enough to be annoying but not so annoying you need to reduce it. That means you're hopefully thorough enough in the logging that you're reporting what you care about and the things you see are the the t…

> because that only scales so far (but surprisingly far for diligent admins) Surprisingly far. We log terabytes of data a day, most of it is unnecessary. I've been trying to tell people that it is not a good idea but so far I've had limited success. It's easy for people to just "printf" everything (we are lucky if logging libraries are used with proper levels). Right now, we have the most expensive 'add' operation in…

mtail is handy for such cases, when you really only care to extract a few metrics from the logs. https://google.github.io/mtail/

Generally though I've found once you start aggregating logs you find many more uses for them.

Re: Never trust a system that seems to be working

#196

Post by jrumbut »

Arainach wrote: post #150
kevincox wrote: post #131

Earlier quoted context omitted.

I may be biased because I am used to the hand but I find the walk and hand shapes are very distinctive compared to the walk and stand. However green on walk would be nice.

Clearly everyone should adopt the (East) Berlin standard: https://en.wikipedia.org/wiki/Ampelm%C3%A4nnchen Very visually distinct, walking and standing, and green/red.

Any kind of figure triggers the walk reaction from me (or it did until someone finally clued me in on a trip to Europe).

My working theory had been green figure means cross, red figure means cross with caution, like a flashing red hand in the US.

Re: Never trust a system that seems to be working

#197

Post by Laremere »

1-more wrote: post #171
mshenfield wrote: post #28

Also a good reminder why exceptions and optionals exist. Bonkers that "I didn't get a response" defaults to 0.

One thing I hated about working with Go. POSTed JSON bodies missing a field could not be distinguished from those where that field pointed was present and pointed to the empty value for that (an empty array or string or something). This may be entirely work-around-able and simply a failure of how that job worked, but it was a whole thing .

In this case, instead of, say, an int, you could have the field be a pointer to an int.

Re: Never trust a system that seems to be working

#198

Post by fknorangesite »

serf wrote: post #188
drewtato wrote: post #154

Earlier quoted context omitted.

https://twitter.com/Foone/status/1581662557470806017

the problem is that while it also breaks search for the inflammatory assholes that want to ruin everyone's day, it also breaks search for everyone else . it's a strange problem, to be sure. "I want to speak publicly about something in the market-place square, but in such a way as to avoid the nay-sayers and rabble-rousers.' -- this seems like a problem that was fixed in ye days' of olde by forming secret collectives…

> it also breaks search for everyone else.

Yes, and that sucks. But you can blame the assholes for that; they're the ones who ruin it for everyone else.

Re: Never trust a system that seems to be working

#199

Post by reaperducer »

usrbinenv wrote: post #88

A bit of an off-topic: I only ever saw white traffic lights in the US and Canada (specifically, pedestrian traffic lights) and they confused me a lot at first - the rest of the world uses green. The icons displayed (hands) are confusing too: the rest of the world uses an icon of a man walking or standing.

the rest of the world uses green.

Only if you define the rest of the world to mean the very small percentage of places in the world you have been.

From Wikipedia:

In some countries, instead of "don't walk", a depiction of a red man or hand indicating when not to cross, the drawing of the person crossing appears with an "X" drawn over it.

Some countries around the Baltic Sea in Scandinavia duplicate the red light. Instead of one red light, there are two which both illuminate at the same time.

Re: Never trust a system that seems to be working

#200

Post by alexchamberlain »

mlazos wrote: post #177

It’s really interesting how factorio problems are pretty much the same as multiprocessing/distributed systems problems. It just shows how universal and fundamental the idea of “work” and “workers” are. An engineer on my old team came up with a credit system to solve this problem, the receiver issues credits to the sender, which only sends when there is a credit available - this ends up with the same better failure mo…

That is the Token Bucket [1] algorithm. Variations can easily be coded to be distributed (use Redis), or account for multiple receivers etc.

[1]: https://en.m.wikipedia.org/wiki/Token_bucket

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