[HN Gopher] Never trust a system that seems to be working
___________________________________________________________________
Never trust a system that seems to be working
Author : pkilgore
Score : 423 points
Date : 2022-10-17 14:10 UTC (8 hours ago)
(HTM) web link (twitter.com)
(TXT) w3m dump (twitter.com)
| gyropop wrote:
| baxtr wrote:
| The tweet has been removed?
| jawadch93 wrote:
| shadowgovt wrote:
| There are two good lessons here:
|
| 1) Robust system design involves identifying the parts of your
| system that are mission-critical and _always_ monitoring them.
| NASA missions have great automation and a 24 /7-staffed mission
| control.
|
| 2) If a system failure _can_ result in massive secondary damage,
| isolate that system. Warehouses receiving orbital payloads should
| probably be nice and far away from the base you care about.
| pjmorris wrote:
| > Warehouses receiving orbital payloads should probably be nice
| and far away from the base you care about.
|
| As mentioned elsewhere in the thread, shades of 'The Moon is a
| Harsh Mistress' by Heinlein.
|
| All your base are belong to dust.
| shadowgovt wrote:
| Sorry, having never read that story (nor played Factorio
| since it went interplanetary) I don't understand the
| reference.
| xani_ wrote:
| > 1) Robust system design involves identifying the parts of
| your system that are mission-critical and always monitoring
| them. NASA missions have great automation and a 24/7-staffed
| mission control.
|
| You should _alert_ on critical parts but you should _monitor_
| anything and everything you can. It might be critical in
| finding out why system broke later on. Easier said than done
| for hardware but easy for software
| sharno wrote:
| Threadreaderapp of the tweets (still live):
| https://threadreaderapp.com/thread/1581643415850098688.html
| Darkphibre wrote:
| Reminds me a lot about the fascinating read of Knight Capital,
| and the $440M-in-28-min bug that lost them 75% of their equity.
|
| Reminds me a lot about Knight Capital bug that cost them $440M in
| 28 min.
|
| > Rogue orders seemed originated from the new RLP router code,
| but no one could pinpoint the bug.... they reverted to last-
| stable.... and even _more_ trades executed than before.
|
| https://www.henricodolfing.com/2019/06/project-failure-case-...
|
| I remember a PDF that went into even greater detail, was a very
| good read.
| snapcaster wrote:
| Great article, made this exact same mistake in space exploration
| before learning to transmit demand and not supply. There are so
| many principles like this I learned from playing through the
| game. One area I've been focusing on improving is trying to
| anticipate how any given subsystem might go wrong and add even
| simple circuitry to detect condition and alarm/signal to the
| factory dashboard. Has cut down on the times where I realize some
| part of factory hasn't been working properly for like 5 hours.
| Applying this to software development has made me better about
| getting better about how I use rollbar logging
| mshenfield wrote:
| Also a good reminder why exceptions and optionals exist. Bonkers
| that "I didn't get a response" defaults to 0.
| a_shovel wrote:
| It's not that "no response" defaults to 0, it's that in
| Factorio's circuit network, "no signal" and "signal with a
| value of 0" are exactly synonymous.
| 1-more wrote:
| 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_.
| Laremere wrote:
| In this case, instead of, say, an int, you could have the
| field be a pointer to an int.
| manicennui wrote:
| And now you've traded one problem for another.
| skeletonjelly wrote:
| Wonder why it was deleted
| neonate wrote:
| https://news.ycombinator.com/item?id=33238679
| dtjohnnymonkey wrote:
| This is a very dramatic illustration of one of the benefits of a
| pull vs push-based architecture.
| 1970-01-01 wrote:
| Isn't the lesson NO SIGNAL != 0
|
| More universally, 0 isn't null.
| joshstrange wrote:
| While I have not really played SE (past initial launch, it was
| too daunting to build the ship in space, etc) I have run into
| these kind of "issues" in Factorio. While they can have
| disastrous effects, I often really enjoy finding the core problem
| and finding a solution to make it "fail-safe".
|
| Sometimes I wish I could go back and wipe all my Factorio
| knowledge and start from scratch again, most importantly refusing
| to use blueprints from the internet except for basic things like
| balancers. Finding early/mid/late game malls/blueprints sort of
| ruined the game for me. Min/maxing is fine by myself but once I'm
| "competing" against the internet or feel obligated to find the
| most efficient/best green/red/blue circuit factory, or science
| packs, etc it really ruins the game for me and makes it feel more
| like a job.
|
| I got a good thousand or two hours out of the game before I hit
| that point and someday I want to try playing it again with self-
| enforced limits on what I'm "allowed" to get from the internet
| and what I need to just figure out on my own. The first game I
| played was pure bliss (and I played with Bob's mods and a number
| of others, yes that was stupid for my first playthrough but damn
| it was fun), I'd love to recapture that.
| aaronscott wrote:
| I want to reinforce your plan. Somehow I played factorio for a
| few hundred hours before finding online communities and
| blueprints. It was a wonderful experience of discovery and
| exploration. I came up with a few "novel" designs during that
| time that I'm still proud of.
|
| Once comparing my own work to the best online it took a lot of
| joy out of the game. But I found that the memory was short
| lived, once I cut myself off from those online communities it
| was easy to fall back into the "let me pull out my sketchbook
| and solve this problem" mindset. I think half the fun is that
| design process.
|
| I'm well north of 1000 hours now, and still discovering new
| ways to play and solve problems. I've come full circle and now
| build spaghetti bases because they are so visually fun.
| joshstrange wrote:
| I've heard this story repeated many times now and I'm glad to
| hear people are able to get back into it after having the joy
| sucked out. I think next time I play I will refuse to use a
| "main bus" until much later in the game if at all. That was
| the one of the biggest joy-killers, trying to plan for a
| mega-base essentially from the very start. It's not fun to
| plan out your bus and leave lots of room for red/blue
| circuits or more science packs while you are still building
| MK1-level things. That or trying to setup production lines
| with room for MK2-MK3+ versions of things from the start.
| It's complete overkill especially since there is no advantage
| to having a bus next to where you start. Better to situate it
| further away where minerals are more dense/plentiful and
| later in the game when it actually makes sense. Looking back
| I can't believe how stupid it was for me to setup 4 lanes of
| iron, 2 of copper, and a handful for each circuit type from
| the very start of the game, it sucked all the fun out but I
| didn't notice the reason.
|
| The game largely felt like I was stuck in the same cookie-
| cutter, always trying to never have to tear up lines or
| rebuild elsewhere (trying to do it perfectly from the start).
| That was easily half the fun of my initial runs, realizing I
| needed to expand or rebuild instead of trying to perfect the
| build order.
| vineyardmike wrote:
| > I think next time I play I will refuse to use a "main
| bus" until much later in the game if at all.
|
| I mostly played through without any internet advice until I
| shared with a friend who _did_ use internet advice and the
| main bus was his advice. Thankfully I already had a base so
| I tried this for a specific process /product (rockets ofc
| but still). I think a lot of "late game" stuff by
| experienced players will likely converge towards a bus
| since you'll be already learned scale and order by then,
| but maybe with less precision in layout. The problem is
| that you can't un-see it once you start building with it
| once.
|
| I agree that fuck perfect from the start, build at the
| right scale at the right time. It's way more fun.
| Conversely, if you like multiplayer games, this is a game
| where it's really fun to play with people who are new. You
| can use their naivete to override your knowledge or build
| completely different looking based each time. It's fun to
| guide them through rediscovery (eg wtf why did all the
| trains dead lock!)
| neonate wrote:
| https://web.archive.org/web/20221017155814/https://twitter.c...
|
| https://archive.ph/cToUl
| piaste wrote:
| A more narrow lesson: this is why all SQL statements involving
| NULL are always false.
|
| > in any case, losing power means the transmitter stops
| transmitting.
|
| > and here's the fun part: your circuit which controls that
| inserter is set to insert "if [ICE] < 8000"
|
| > and GETTING NO SIGNAL AT ALL counts the same to it as ICE=0.
|
| > 0 is < 8000.
| branko_d wrote:
| A CHECK constraint treats NULL as true.
| sidpatil wrote:
| In industrial automation, one old and popular analog signal
| scheme is the 4-20 mA current loop [1]. Why 4mA instead of 0mA?
| Because that way, you know 0mA specifically indicates a fault
| caused by a failed sensor, break in the line, etc.
|
| [1] https://en.wikipedia.org/wiki/Current_loop
| [deleted]
| [deleted]
| dekhn wrote:
| My favorite is, after fixing a system in prod, asking "how did
| that possibly work in the first place?"
| ziml77 wrote:
| I've totally asked that many, many times. But sometimes the
| answer is actually quite simple: no one was ever paying
| attention to the outputs of that piece of the system.
| dekhn wrote:
| well, I'm the sort of person who digs around logs of
| ostensibly working systems just to find problems, which has
| been very useful in identifying long-tail problems (like, 1%
| of your network cables are blipping but the application just
| runs slower instead of failing).
| known wrote:
| lordnacho wrote:
| Same goes for work. If you join a well oiled machine that just
| seems to be working great, you may never understand how it works,
| since you won't be exposed to various people diagnosing issues.
| Join a place that used to work and is now creaking, or a place
| that never worked, and there's more pain but also more learning.
|
| Also when does a Factorio system ever work? There's permanently a
| pressure for it to do more, stuff stuck on the wrong belts, not
| enough of some input...
| roflyear wrote:
| I think this is the classic "when it is working well, no one
| notices"
| nostrademons wrote:
| If you use a calculator and then carefully design out the
| logistics & geometry of your factory, you can build stuff that
| basically "just works" once you iron out the missing inserters
| & power poles. You get bottlenecks when you focus on one
| product at a time instead of looking at how the system as a
| whole functions.
| georgyo wrote:
| > Also when does a Factorio system ever work? There's
| permanently a pressure for it to do more, stuff stuck on the
| wrong belts, not enough of some input...
|
| Sounds like a growing SaaS company.
| michaelmior wrote:
| Whenever I write a non-trivial amount of code that appears to
| work the first time, I'm immediately suspicious. I probably spend
| more time testing that code than I would have if I had broken and
| fixed some things along the way.
| deworms wrote:
| He's mad we're not indulging in his fantasy
| dang wrote:
| You've been using HN repeatedly for ideological battle. We ban
| accounts that do that, so please stop doing that. It's not what
| this site is for, and it destroys what it is for.
|
| https://news.ycombinator.com/newsguidelines.html
| raldi wrote:
| Tests that output booleans (pass/fail) are an antipattern.
|
| Tests and their dashboards must distinguish "the testing system
| worked and the test failed" from "the testing system failed".
| danuker wrote:
| Most testing frameworks distinguish between failure (aka
| assertion violation) and error (invalid or nonexistent test
| result).
|
| But there may be mistakes writing the tests (false success
| result). To check the tests, I break the implementation, then
| check that they fail.
| sgtnoodle wrote:
| I dunno, I think regression tests are inherently boolean.
| Either it passed or it didn't. The code path that the system
| takes to get to a green light or not is arbitrary. If you start
| using an enum to return the result of the test, folk tend to
| add more and more enums over time until it's overly
| complicated. Processes return an 8 bit integer, but 99% of the
| time all anyone checks is whether it was 0.
|
| There's certainly practical benefit to being able to quickly
| triage a test failure. Tests that _only_ output booleans are
| annoying. When there is a failure, it 's helpful to have some
| out-of-band information about why it failed. That's typically
| provided via console output, but you can make whatever complex
| logging system you want.
| raldi wrote:
| If a regression test fails, you alert the programmer who
| kicked it off and maybe roll back the checkin.
|
| If the regression testing system has an error while running a
| test, you page the oncall SRE and maybe try to rerun it. You
| certainly don't roll back any checkins.
| LastTrain wrote:
| Which can be loosely translated to "Never trust a system" Also,
| never trust someone who cites "The Moon is a Harsh Mistress",
| which can be loosely translated to "Never trust a self-described
| Libertarian"
| vaidhy wrote:
| I think that should have gone over my head as I do not remember
| anything in the book to be libertarian. Maybe the final part
| where they are trying to set up the lunar government, where the
| libertarian stuff fails in practice?
| dang wrote:
| " _Eschew flamebait. Avoid generic tangents._ "
|
| https://news.ycombinator.com/newsguidelines.html
| potatototoo99 wrote:
| What does it have to do with Factorio?
| Tomte wrote:
| You mean apart from the Factorio screenshots and the Factorio
| gameplay specifics?
|
| The thread's start is here, btw:
| https://mobile.twitter.com/Foone/status/1581643197427523584
| tslater2006 wrote:
| The linked tweet is part of a larger thread which details an
| issue with how they set up transmitters in factorio which led
| to the destruction of the entire base. The thread then pivots
| to how it applies to other areas.
| potatototoo99 wrote:
| Ah thank you, that makes sense now. I'm not too used to how
| Twitter is organized.
| [deleted]
| Arainach wrote:
| Tweet seems to be deleted now. A brief summary of what it was:
|
| * In Factorio (game) you can have space stations that send
| supplies to your ground base
|
| * If the supplies are not caught, then they cause damage to your
| base
|
| * To avoid sending supplies that cannot be caught, you can use
| logic controls
|
| * A common approach is to have the station say "if (ground supply
| < X) send"
|
| * This fails if the ground supply loses power, as no signal is
| interpreted as 0 and 0 < X
|
| * Thus, the system will appear to work until your ground base
| loses power, at which point it will be destroyed
|
| * A better system is to have the ground base use logic to say "if
| supply < X send signal" and the station to say "if signal
| received, send". This way, a power failure fails safe instead of
| fails active.
|
| With a fun callout to
| https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress
| foone wrote:
| It was deleted because it was posted here.
| deworms wrote:
| NateEag wrote:
| Would you be willing to explain why you chose to delete the
| tweet after a link to it appeared on HN?
| TaylorAlexander wrote:
| https://news.ycombinator.com/item?id=33238680
| sjs382 wrote:
| Needing to run through this discussion every time HN gains
| interest in one of their posts is a compounding reason, I'm
| sure: https://news.ycombinator.com/item?id=33238680
| irskep wrote:
| Some people dislike interacting with the HN community for
| one reason or another. I imagine that's the case here. This
| person definitely isn't the only one.
|
| Getting a post or tweet picked up by a large community who
| doesn't see your stuff regularly can be a lot more
| stressful than speaking directly to your audience (in this
| case, direct Twitter followers) who have a lot more context
| on your work.
| CaliforniaKarl wrote:
| In this case, there's no need to imagine. Their latest
| Tweet has the answer.
| jstanley wrote:
| I can only see 1 comment in this thread that uses "he" to
| refer to a person, and it refers to a different person,
| so I'm not sure I follow.
| tbodt wrote:
| There are plenty, but you may have to turn on showdead
| and scroll to the bottom and uncollapse to see them.
| unsupp0rted wrote:
| It seems to be about misgendering on HN?
|
| I never understood why it's such a big deal. When people
| guess wrong about my gender, ethnicity, preferred spoken
| language, etc, I correct them.
|
| I guess if they were to argue with me about the
| correction and insist their guess was right, that would
| get old fast and I'd be as frustrated as foone.
| ranger207 wrote:
| It happens much more frequently by people with malicious
| intent to them. All you have to do is say once that
| misgendering is annoying and them trolls will latch on
| and do it intentionally to harm you
| bentcorner wrote:
| bobsmooth wrote:
| Why is discussion on a different website so distressing? Are
| there people from HN harassing you on twitter?
| quitspamming wrote:
| It's trendy to hate HN by some on Twitter.
|
| *edit to provide context. this isn't unique to twitter/hn.
| it's trendy on reddit to hate tiktok and instagram. it's
| trendy on 4chan to hate reddit.
| zelse wrote:
| Sure, except in this case foone has explained exactly why
| they dislike their stuff showing up on HN.
| quitspamming wrote:
| i edited my comment to provide a little more context but
| just because someone provides reasons doesn't mean it's
| not influenced by the trend. reddit's trend to dislike
| tiktok has valid points but it's also fueled by the
| trend. i've criticized hn here on hn so this isn't me
| trying to defend the site.
| remram wrote:
| They also seem to hate Factorio itself, which is the
| reason that while they play it and tweet about it so
| much, they mangle its name. I don't understand it, but
| everyone is free to remove what they want from their own
| Twitter I guess.
| xani_ wrote:
| That's also easier way to design it in Factorio. When I was
| playing with Space exploration mod that's precisely what I did,
| the base sent "shopping list" and the provider sent stuff on
| that shopping list
| csours wrote:
| If your code has side effects, it only ever seems to be working.
|
| ----
|
| > the newbie says "aww, why isn't it working?"
|
| > the intermediate says "yay, it's working!"
|
| > the expert goes "hmm, why is it working?"
|
| I've also seen this as
|
| My thing isn't working and I change X and now I get error J
| instead of error K, so now I have to change X back because it's
| still not working.
|
| Where K is a "better" error than J, such as K = failed to connect
| and J is Server 500 error. With J you are at least talking to a
| webserver.
| hinkley wrote:
| No news is bad news.
|
| I don't like code that compiles cleanly or runs cleanly on the
| first try. The worst is when I know that code isn't close to
| done yet. Without errors my list of actionable tasks is low. I
| know there are a certain number of problems, and if I can't see
| any it's because they're invisible, not because I don't have
| any.
| Taywee wrote:
| I came here to say this exactly. There's nothing more
| stressful to me than when a lot of freshly-written C++
| compiles without error or warning on the first try, and then
| seems to run without issues. I get the distinct feeling that
| there is a problem that I'm just not seeing yet.
| xani_ wrote:
| Eh, that heavily depends on language. Some have better
| tooling to get most of the typical errors out before the
| compile.
|
| That being said I'm always suspicious and start to fiddle
| with them if I see test + code pass on first time
| bee_rider wrote:
| Working with beginning programming students, "Yay, now we have
| an error message that makes sense" has become my catchphrase.
| csours wrote:
| "Read the error message, no wait don't close that go back"
| when helping people is a definite feeling.
|
| Take a deep breath. Take off your headset. Go outside. Never
| look at a computer again. Start driving a bulldozer. Life is
| good.
| alexchamberlain wrote:
| It's amazing the number of junior engineers I've taught to
| simply read the error message properly.
| macintux wrote:
| I've lamented here before, but the number of _technical_
| people who absolutely freeze up at the sight of an error
| message is daunting. Being able to interpret errors
| correctly is a huge step up in this industry; to me it
| feels like table stakes, but clearly isn't.
| JoshTriplett wrote:
| > I've lamented here before, but the number of technical
| people who absolutely freeze up at the sight of an error
| message is daunting.
|
| "freeze" is still a _much better_ reaction than "quickly
| dismiss without paying attention". I can understand
| "freeze"; it's possible to learn and train from there to
| "good, well done, now read everything and think". I _do
| not understand_ "quickly dismiss without reading and
| paying attention".
|
| (I know about the studies for "people dismiss something
| that isn't getting them their goal", but I still don't
| understand the _mindset_ that can dismiss something like
| that even when theoretically trying to figure something
| out.)
| atomicnumber3 wrote:
| Part of the problem is that we've trained everyone,
| _especially_ nontechnical people, to ignore and dismiss
| stuff.
|
| You're using a program. A thingy pops up or unexpectedly
| shows up that interrupts you.
|
| 80% chance it's some stupid ad or newsletter thing.
| Dismiss with prejudice.
|
| 19% chance it's a "oopsie poopsie we did and whoopsie,
| the server monkeys are working VERY HARD to fix this,
| sowwy!!" and then the app still works apparently just
| fine, or if it doesn't you just force close and re-open
| the app.
|
| 1% of the time it's an ad again.
|
| In the remaining floating point error's worth of %, it's
| an actual actionable thing a user could action to fix the
| issue.
|
| I don't really blame people for just predicting that a
| pop up will be useless because it probably will be.
| SilasX wrote:
| Similarly, the joke that the engineer's second worst nightmare
| is, "it doesn't work but it should", while their worst
| nightmare is, "it works but it shouldn't".
| hinkley wrote:
| That's the surest way to nerd snipe some people. This code
| doesn't work, and yet it does. After reading the commit
| history, it in fact never worked, and yet it has been up
| until yesterday. What in the actual fuck.
| xani_ wrote:
| The buggy behaviour of A caused buggy behaviour of B that
| caused buggy behaviour of C, just so happened to align
| enough to "look like it is working".
|
| Double fuckup if the thing is backups and your data is
| gone. Reason why we check not only "does the backup job
| finished" but also "does the size looks right", because
| backup with 0 files still returns OK...
| SilasX wrote:
| Haha yeah, been there. I forget all the details, sadly,
| but there was some long-present bug with how the frontend
| architecture word in the dev environment that would keep
| the changes from being propagated. But every member of
| the team had set up a workaround so that, on their
| machine, it would load the correct assets some other,
| undocumented way, so they wouldn't notice the bug.
| csours wrote:
| I used to do industrial tech support and this gives me the
| raging anxieties.
| beckingz wrote:
| I have an exceptional ability to fix things: often I can
| fix things before determining why they are not working.
|
| This is immensely frustrating because I like to understand
| mechanical and electrical devices and take pride in my
| craft, so if I fix something too easily I don't trust that
| the fix will hold without a mental model of the thing.
| 0xbadcafebee wrote:
| 2 thoughts:
|
| 1. wow there's a game where you become a sysadmin
|
| 2. how many tweets are there just to make his point? 200? nobody
| thinks "maybe this will be more coherent on a single page"? I
| don't get social media
| Sebb767 wrote:
| Foone also has a few hundred Tweet Twitter rant about why they
| are using Twitter, so at least they are consistent.
| city17 wrote:
| Was thinking the same. Once you exceed like 5 tweets in a
| thread, it becomes a small article and you would've been better
| off just writing an article in the first place. If you check
| the thread reader below you can see just how unstructured and
| incoherent it is compared with a simple article.
| fknorangesite wrote:
| If you're genuinely curious:
|
| > I have ADHD: it makes writing blogs hard but Twitter easy.
| So it gets quickly tiring that every time I'm posted there
| [to HN] that the comments immediately go "why isn't this a
| blog? Twitter is a bad site for this kind of writing and I
| hate it blarg"
|
| https://twitter.com/foone/status/1440695857699962893
|
| This exact comment of yours is a prime example of why foone
| hates it when their tweets are posted here.
| city17 wrote:
| Thanks, that's interesting. I can see why it's easier for
| him to tweet in that case. But still doesn't change the
| fact that an article is easier to consume for the reader.
| zelse wrote:
| Foone is a them, not a him.
|
| And yeah, you're right, it's definitely easier for the
| reader, but the author isn't required to make it easy for
| their audience -- if it was, Judith Butler wouldn't
| Judith...Butle and James Joyce wouldn't James Joyce.
| Foone writes tweets, 149k people have chosen to read
| their tweets. Personally, while I agree a blog'd be nice,
| I'm just glad foone makes their knowledge available.
| conradfr wrote:
| How does that make sense? You write the same amount of text
| in the end.
| ranger207 wrote:
| The dopamine hit from click the send button can help
| overcome the ADHD tendency to wander off task. Plus, even
| if you have half an essay posted to Twitter and still get
| bored, it's much more difficult to just leave it halfway
| finished than to leave an unposted blog post in your
| drafts. And besides that, I'm really not sure why people
| get so upset at people putting content into the world.
| Wasn't the point of the internet to make it easier for
| people to share their knowledge with the world?
| conradfr wrote:
| Personally I don't care too much.
|
| But on the other hand I have ADD and there's a chance I
| get bored with a twitter thread and move on before
| finishing it while a blog post allows me to keep it open
| in a tab and read it in steps.
| positr0n wrote:
| What drama with the Factorio devs is he talking about at the end
| (and namesearchers?.. I don't get Twitter sometimes)
|
| I've never heard anyone say anything about the Factorio devs
| except praise their productivity and professionalism.
| shp0ngle wrote:
| One dev said in one post that they like Uncle Bob.
|
| I think that's it.
| teraflop wrote:
| Well, that and a number of follow-up comments from the same
| developer, such as this one: https://www.reddit.com/r/factori
| o/comments/o2ly6f/friday_fac...
|
| A lot of people have (understandably) lost patience with the
| "just asking questions" style of rhetoric, and don't
| appreciate others making excuses for it.
| conradfr wrote:
| I don't get what's bad or "anti-trans" in this post?
| shp0ngle wrote:
| adhoc_slime wrote:
| The Uncle Bob from clean code(er)?|architecture?
| unsafecast wrote:
| Yes.
| pjc50 wrote:
| > "saying the name of the game uncensored is going to get
| namesearchers and I have a transflag in my name so guess what
| kind of response I'd immediately get?"
|
| I believe kovarex made some anti-trans statements once, and
| gamers in general are prone to making abuse pile-ons, so it's a
| mitigation against that.
| mschuster91 wrote:
| > I believe kovarex made some anti-trans statements once
|
| Nah, publicly advertised for and defended some right-wing
| Youtuber. [0]
|
| [0] https://knowyourmeme.com/memes/subcultures/factorio
| [deleted]
| taink wrote:
| Uncle Bob? Stating he is just "some right-wing youtuber"
| sounds mildly reductive, the guy co-authored the agile
| manifesto[0].
|
| I won't go as far as defending his views, but recommending
| his talks and books seems pretty normal to me.
|
| [0] https://en.wikipedia.org/wiki/Robert_C._Martin
| arsome wrote:
| He doesn't even have a whole "getting cancelled" section
| on his Wikipedia page yet, can't be that bad.
| Sakos wrote:
| Might as well cancel most programmers while we're at it.
| It's insane to lambast him for this when all he did was
| recommend some of Uncle Bob's videos on project management
| and programming.
| [deleted]
| mplewis wrote:
| Kovarex promoted Uncle Bob in the past, who has generated a
| drama vortex of his own.
| yottabyte47 wrote:
| foone's pronouns are they/them
| freedomben wrote:
| We once learned a good lesson about this, as well as recognizing
| the real threat that ESD poses. We once had a terrible failure
| that was the result of a main signaling line being damaged by ESD
| such that it had much higher resistance than it should have. Our
| signal levels were too close such that it danced over the line a
| few times and got interpreted as the opposite value, but only
| sometimes. It also taught a good lesson that when the robots _do_
| become self-aware and take over the world, it 's gonna hurt like
| hell.
| ncmncm wrote:
| Amorymeltzer wrote:
| Just want to note that the novel noted in the first post, _The
| Moon Is A Harsh Mistress_ , is a great read. I think I read it
| after seeing it recommended in Mary Robinette Kowal's Lady
| Astronaut series, but it's a nice balance of technical and
| science fiction with politics, almost like a condensed version of
| KSR's Mars Trilogy. It's mostly (not entirely) devoid of the more
| typical Heinlein sexism/objectification.
| bb101 wrote:
| It seemed to me to be a handbook on how to conduct a
| revolution. Much as Heinlein's _Stranger from a Strange Land_
| was a handbook on how to start a religion (hello
| Scientologists).
| usrbinenv wrote:
| 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.
| Manu40 wrote:
| Don't know about Eastern Canada, but over in Western Canada,
| the only white signal light is the walking person symbol for
| cross walks. Otherwise, it's Red, Yellow, Green lights for the
| traffic, and a red hand or white walker for crossing the
| street.
|
| Just figured I'd mention that.
| gpm wrote:
| I don't know that I've seen all of eastern Canada, but of the
| parts of it that I have seen the exact same is true.
| malloci wrote:
| The hand is to mimic that of a traffic cop. When they want you
| to stop, they hold up their hand to indicate that you need to
| stop.
|
| It used to be that you had to know english in order to
| understand them as well...many of the signs used to use the
| words "walk" and "don't walk"
| oangemangut wrote:
| :D I have a few of the "Walk" (in white) and "DON'T WALK" (in
| orange) signals around me in PNW.
| usrbinenv wrote:
| 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 from the rest of the world and had no idea how others
| were doing things. I don't quite understand it.
| Lukas_Skywalker wrote:
| 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).
| samatman wrote:
| 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.
| Lukas_Skywalker wrote:
| The term _reflex_ has changed over the years.
|
| Back in 1649, when Descartes formulated the concept of a
| reflex, it was used to describe lower animals, to support
| his notion that they were automata without a mind on
| their own. The word _reflex_ originated from the
| "reflection" of the sensory input into a response. The
| physiological backgrounds were not yet known.
|
| In the early 19th century, Hall narrowed the definition
| of a reflex to be a "involuntary action of a muscle or
| gland in response to the stimulation of a receptor
| neurone which does not depend on the existence of
| consciousness".
|
| Sherrington, in 1904, narrowed the definition further,
| introducing the concept of the "reflex arc", a hardwired
| pathway between receptors and effector muscles.
|
| Pavlov later did a strange thing and _widened_ the
| definition, which is the source of some confusion.
| Nowadays, Pavlov 's _Conditioned Reflexes_ are mostly
| called _Conditioned Responses_ , to avoid this exact
| confusion. NB: there are people arguing that
| _conditioned_ is a mistranslation, and that it should
| mean _conditional_ , which makes more sense in the
| context.
|
| Pretty much every current publication uses the term
| "reflex" for involuntary, inborn responses, detected by
| receptors, transported to the spinal cord by afferent
| nerve fibers, processed there, and the motor signal sent
| through the efferent nerve fibers to the effector
| muscles. I only found the term "conditioned reflex" in
| papers discussing Pavlov's experiment.
| ianferrel wrote:
| >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)?
|
| In many cases the US were _the first_ to mass-manufacture
| things to some kind of standard, so the question is really:
| why did the rest of the world choose a different standard.
| Often they have a good reason (better design, maybe), but
| the US also has a good reason for not switching (inertia,
| existing tooling, people understand the existing standard).
|
| The US was the first place that traffic light and crossing
| signals were installed. The reason they didn't go with the
| standard the rest of the world uses is that it didn't
| exist.
| throw827474737 wrote:
| > In many cases the US were the first to mass-
| manufacture..
|
| Traffic lights? Not so many actually?
| romwell wrote:
| The curse of innovation: you might end up being stuck
| with it while the rest of the world learns from your
| mistakes.
|
| Case in point: Ma Bell. And things like signing the
| credit card receipt.
| zoover2020 wrote:
| And standards don't adapt? To me this feels wrong and
| backwards
| ianferrel wrote:
| They do sometimes.
|
| Like, the WALK / DONT WALK crossing signals that were
| around in my youth were slowly replaced with the HAND /
| WALKING PERSON ones, I'm sure because they're better for
| people who don't read English.
|
| But also there is a cost to change, and it's often not
| worth doing if the benefit from the new system or
| standard isn't _a lot_ better than the old.
| randomdata wrote:
| They do when there is good reason, but there isn't always
| good reason.
|
| In fact, a theoretically better standard could actually
| be worse in some situations if people are accustomed to a
| different standard. Imagine if America had settled on red
| for go and green for stop, and then tried to change the
| standard to match the rest of the world. It would be a
| calamity as some drivers continued to adhere to the old
| standard that they knew.
|
| Stop signs were originally yellow, so such a change isn't
| unprecedented, but in that case they also contained the
| word STOP so the colour wasn't critical to understanding
| the sign. Standards can more easily change when there is
| backwards compatibility available. More recently, some
| jurisdictions have started adopting traffic light shapes
| (square = stop, diamond = caution, circle = go) but
| retain coloured lights for backwards compatibility.
| creeble wrote:
| Indeed, sometimes they do and sometimes they don't.
|
| Why doesn't the rest of the world (outside the US) have a
| 3rd middle brake light (CHMSL), as was mandated in the US
| in 1986?
|
| My guess is because, despite measurements of ~22% crash
| avoidance at the time, that number turned out to be
| between 0% and 4% in practice. Maybe the rest of the
| world didn't care about 4%, or maybe they thought it was
| as stupid then as it turned out to be.
|
| But the CHMSL standard in the US has refused to die.
| greycol wrote:
| When ATMs were first implemented they would dispense
| money before or at the same time as giving your card
| back.
|
| This resulted in premature conclusion errors. They went
| to the ATM to get money. They got their money so they
| left... forgetting their card.
|
| When ATMs were updated they fixed the design error. Now
| the card popped out and had to be removed before money
| would dispense. This resulted in a spike of people
| leaving with money hanging out of the ATM because they
| had been trained that removing their card was the end of
| the task. (Which is why money now gets sucked back into
| the machine if it hasn't been removed fast enough).
|
| The point of the anecdote (other than that you hire HCI
| experts before implementing an interface) is that
| implementing a new and objectively better system doesn't
| necessarily result in an objectively better outcome when
| replacing an incumbent worse system.
| metabagel wrote:
| "It's as if the western hemisphere was completely cut off
| from the rest of the world and had no idea how others were
| doing things. I don't quite understand it."
|
| Seems like you understand it fairly well. I can't speak for
| Canada, but the U.S. mostly ignores how other parts of the
| world do things.
| [deleted]
| knorker wrote:
| And they call it "green", despite the fact that it's obviously
| white.
|
| I agree with you. When I'm in the US I keep scanning for a
| green light, so it takes me a while to find "the white man"
| telling me it's OK to cross.
| yamtaddle wrote:
| I would think you'd specifically want to avoid displaying
| lights of the same color as "go" for auto traffic, for purposes
| other than telling auto traffic to "go". So I'd be inclined to
| avoid green for pedestrian "go", if I were designing such a
| system. But maybe that's not actually a problem, IDK.
|
| > The icons displayed (hands) are confusing too: the rest of
| the world uses an icon of a man walking or standing.
|
| Is a hand held up, palm-out, not a signal for "stop" in places
| other than the US or Canada? I wouldn't assume it's universal,
| but I'd expect it's got broader reach than that.
|
| Besides, again, I'd personally assume it'd be better to have
| _very_ different icons for "walk" and "don't walk". Not two
| different depictions of a person.
| layer8 wrote:
| It can also mean "Greetings, Earthling".
| kevincox wrote:
| 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.
| mdavidn wrote:
| I always assumed the pedestrian light was white to avoid
| confusion with the green traffic light for parallel drivers.
| Arainach wrote:
| 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.
| jrumbut wrote:
| 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.
| lostcolony wrote:
| I find them far less distinct than a walking person and a
| hand...and if I was colorblind that would be a large
| problem for me (and colorblindness was the reason for
| distinguishing the shape in the first place, so makes sense
| to have very different shapes rather than both "stick
| figure with hat").
| callalex wrote:
| The white crossing indicator lead to a hilarious situation for
| me once. I am colorblind and always assumed the walking guy is
| green just like car signals. One day when a person I was
| hosting from Indonesia was walking in downtown San Francisco
| with me, we were talking about traffic conventions. He said to
| me "Here things are very easy. You just wait for the white man
| and then you cross!" I thought he was making an poor-taste joke
| about following the locals when traveling, and it took quite a
| while to clear everything up! And I learned something new about
| my own country's traffic signals.
| dang wrote:
| We detached this subthread from
| https://news.ycombinator.com/item?id=33235298.
| MBCook wrote:
| I've never seen a white traffic light, but pedestrian crossing
| lights are often white/red still.
| wongarsu wrote:
| 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?
| smolder wrote:
| Possibly. I think people in the US strongly associate
| "traffic" with cars and don't generally think of the
| crosswalk indicators as "traffic lights".
| andirk wrote:
| Best choices to pick on captcha are not what you think is
| pictured but what you think most people think is pictured.
| MBCook wrote:
| 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?
| wongarsu wrote:
| Since about 60% of the visitors of most English-speaking
| websites are American, I assume that requires finding the
| American answer. But that requires me to jump not just a
| language barrier but also a cultural barrier to figure
| out nuances like "what constitutes a traffic light? Do
| pedestrian lights count? Do the poles and cables count,
| or just the light-emitting part?" "What constitutes a
| street sign" "Is a Mecedes Sprinter with windows a bus
| (it's one of wikipedia's example of a minibus)?".
|
| In the end the known unknowns aren't that bad, just
| assume laziness and choose whatever checks the least
| boxes. But the unknown unknowns are regular culture
| shocks. Like pedestrian lights not being considered
| traffic lights.
| djhn wrote:
| Buses are bad, but I feel trucks are even worse. Or
| actually vehicles in general. What does a Venn diagram of
| cars and trucks look like? Are Vespas and trikes
| motorcycles?
| reaperducer wrote:
| _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.
| smoochy wrote:
| I've been to all continents except maybe Australia. Only
| North America has the weird white light for pedestrians and a
| red palm (which also blinks, which is very counter-
| intuitive). I can assure, most countries of the world use red
| and green icons of man standing/walking for pedestrians.
| reaperducer wrote:
| _I 've been to all continents except maybe Australia_
|
| Maybe Australia? You don't remember if you've been to
| Australia?
|
| Congratulations! I've never been so drunk that I didn't
| know which continent I was on.
| kevin_thibedeau wrote:
| It's a retrofit of the older WALK/DONT WALK signs.
| matchagaucho wrote:
| Not familiar with this particular game. But in real-world systems
| design the default should be (?) boolean deliver
| = false; while( polling ){ deliver =
| readyToReceive(); if( deliver ) { send();
| } }
| outworlder wrote:
| If 'readyToReceive()' returns a bad value you could have the
| same problem. Imagine it is an async external call, it fails,
| and whoever wrote the error handling did "return 'error'".
|
| Now you have the same problem.
| TaylorAlexander wrote:
| As I and others have previously pointed out [1] foone uses
| they/them pronouns and feels particularly frustrated when their
| posts get featured on HN, because users here seem unable to honor
| this simple preference of theirs. It looks like they deleted
| their tweet out of frustration with todays latest round of
| misgendering.
|
| I hope people on HN will learn to respect all members of our
| community. Yes that involves not assuming every person online is
| a man!
|
| [1] https://news.ycombinator.com/item?id=32978438
| throwawayallday wrote:
| endianswap wrote:
| > no one is getting dehumanized
|
| [citation needed]
| dang wrote:
| " _Don 't feed egregious comments by replying; flag them
| instead._"
|
| https://news.ycombinator.com/newsguidelines.html
| throwawayallday wrote:
| dang wrote:
| We've banned this account for ideological flamewar. Please
| don't create accounts to break HN's rules with.
|
| https://news.ycombinator.com/newsguidelines.html
| [deleted]
| tbodt wrote:
| I did a quick search on the comments page for "he"+"him" and
| found nothing referring to foone, and was about to congratulate
| HN for getting it right, and then thought to scroll to the
| bottom of the page and found a dozen dead/autocollapsed
| comments, most including the wrong pronouns. At least they're
| where they belong.
| tiborsaas wrote:
| Oh cool, a random tweet from the middle of a twitter rant.
|
| Unleash the chaos monkey's just in case, not to get too
| confident.
| elteto wrote:
| Wow, Factorio is approaching Full Time Job levels of detail and
| work required to keep everything running. Incredible game that I
| will never play, I feel I'm back at my job!
| hardolaf wrote:
| For most of these things, you just make a blueprint and stamp
| it down repeatedly.
| ambicapter wrote:
| Exactly why I stopped playing the game fairly quickly.
| dysoco wrote:
| Usually games or hobbies that feel like a job are much more fun
| because there's nothing wrong happening if you fail at it, or
| if one day you decide not to show up.
| ridgered4 wrote:
| And you don't have to fill out a bunch of paperwork whenever
| you do or change anything.
| elteto wrote:
| Definitely with you on your second point, but not on your
| first. Failing is extremely stressful for me!
| nostrademons wrote:
| Jobs get pretty fun too if nothing seriously bad happens if
| you fail at it. That's why so many people who are financially
| independent keep working.
| Kiro wrote:
| This is a mod that seems extremely boring and tedious. The base
| game is not like this.
| rcxdude wrote:
| Space exploration is a mod which has extra automation
| challenges compared to the base game, and it's probably got
| some of the most interesting ones compared to other mods
| which tend to just have the same basic concepts as the base
| game, just with many more steps piled on, which are probably
| more on the tedious side (pyanodons mods being the most
| infamous in this regard).
| thelopa wrote:
| It definitely can be. I don't think it needs to be as long as
| it is. With 5 space science categories, each with 4 tiers,
| and each tier requiring 4 unique data cards with one common
| ingredient and one catalog recipe for the tier, one insight
| per category, there are ~125 intermediate products to
| manufacture that don't really pose any new interesting
| logistical challenges. For example, once you set up iridium
| processing, the 20 intermediates you need to manufacture to
| finish all 4 tiers of materials science are pretty
| straightforward. Sure, dealing with the scrap generated in
| the process of making those intermediaries is a logistical
| challenge that becomes harder the deeper you progress, but
| they probably could have presented that logistic challenge
| without requiring you to set up production for 25 separate
| products -- most of which are ONLY useful for making
| materials science packs.
|
| I have really enjoyed the puzzles it has posed in the form of
| circuit network logic for automating rockets and spaceships.
| The issue described in TFA is just the tip of the iceberg. My
| factory has deadlocked in a number of interesting and unique
| ways over the course of the 600 hours I've played thus far.
| I've enjoyed the mod. It has some very interesting ideas and
| challenges. It's a shame those puzzles are hidden behind so
| much slog.
| outworlder wrote:
| > This is a mod that seems extremely boring and tedious.
|
| It doesn't have to be, though. I'm currently playing Space
| Exploration + Krastorio 2. Krastorio modifies the early/mid
| game, Space Exploration meddles a little with the early game,
| but most of it is late game.
|
| There are a few more inputs required for things so they can
| get more complicated. And with Krastorio the early game is
| extended (you have "burner" versions of the science lab and
| assembly machines). So yes, earlier game is a little slower.
| On the other hand, it gives you stuff to make up for it. You
| don't require as much science(at least, before space) and
| there are things like core miners, which provide infinite
| resources so you don't have to keep moving miners. Also new
| power generation.
|
| I guess that it depends on what you want to do. Base Factorio
| you either play until you launch the rocket, or you move on
| to megabases. If you want to do that, it's perfectly fine.
| However if you want to keep playing, it's a lot of the same,
| only bigger. Space Exploration essentially _starts_ once you
| launch the rocket. I don't want to do megabases so it seems
| ok with me.
|
| Also, spaceships :)
| speeder wrote:
| Burner things is from space exploration too. Krastorio
| doesn't change the very early game.
| Chico75 wrote:
| That's very subjective. It also adds a ton of new gameplay
| components that push factorio players to better think about
| how to manage their logistics which is fun for some players
| (not all for sure)
| soneil wrote:
| To be fair - this specific issue is with Space Exploration, a
| mod that's specifically for people who decided that Vanilla
| didn't hurt quite enough.
| civilized wrote:
| Statisticians learned long ago that "missing" needs to be treated
| special. It should be either an entirely separate signal or a
| "sentinel value" riding on the existing signal that everyone
| knows and couldn't possibly be a normal operation value. Which is
| why sentinel values are usually a huge bunch of 9's or the
| maximum possible value of the field or something.
|
| Interesting that the sentinel value is zero in this case. In data
| analysis that's usually a terrible sentinel value, but here it's
| the most practical one.
| sharno wrote:
| This sounds close enough to Golang where a null value is
| basically a zero value. I think that would be another million
| dollar mistake that would need fixing later in the language
| alexfromapex wrote:
| I think "never" is too polarized, maybe "be skeptical of" is a
| better suggestion.
| encoderer wrote:
| I've built a pretty successful software monitoring business off
| of this basic premise.
| throwawaymaths wrote:
| Someone just figured out how erlang's gen_servers work and why
| you should use call instead of cast unless you really know what
| you're doing
| camdenlock wrote:
| ricardobeat wrote:
| carry_bit wrote:
| Full thread unroll:
| https://threadreaderapp.com/thread/1581643197427523584.html
| Tao3300 wrote:
| mlazos wrote:
| 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 mode that the article
| discovers and allows you to overlap communication with work.
| alexchamberlain wrote:
| 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
| righttoolforjob wrote:
| Semaphore, Dijkstra, around 1962-1963
| KMnO4 wrote:
| eenell wrote:
| For what it's worth, the author of the twitter thread hates it
| when his threads get linked on HN.
| [deleted]
| yottabyte47 wrote:
| foone's pronouns are they/them
| grimmn wrote:
| [deleted]
| gyropop wrote:
| lawrenceyan wrote:
| In the self-driving context, this reminds me strongly of Tesla
| Autopilot. Good enough to work most of the time, but likely would
| end up in greater overall injuries/accidents per mile if actually
| enabled at scale.
|
| Waymo, Cruise, Aurora, and others are doing it the right way.
| Jupe wrote:
| Well, I was driving home yesterday, and the integrated
| navigation map of my car was randomly rotating 180 degrees
| every few moments, just long enough to be noticeable on-screen,
| but then flipped back.
|
| I have no idea why (something in the compass integrated in the
| car? was GPS being hacked?). But the thought I kept having was
| "If I had a self-driving car, what would be the impact of
| this?". All I could think of was horrendous disasters for me
| and the other cars around me on the road.
| freeqaz wrote:
| "This Tweet has been deleted" -- does anybody have a mirror?
| Maybe @dang can update the main link to that.
| bombcar wrote:
| https://threadreaderapp.com/thread/1581643415850098688.html
|
| https://archive.ph/cToUl
|
| but foone doesn't like the orange site so we probably shouldn't
| link (another advantage to running your own site, you can make
| refers you don't like see goats)
|
| https://threadreaderapp.com/thread/1582089029096382464.html
| tightlips wrote:
| Karellen wrote:
| 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 "fundamental failure mode theorem" will provide
| interesting further insights on this.
| AceJohnny2 wrote:
| Thanks! I read this years ago and have been sharing the concept
| with colleagues, but couldn't remember where it came from.
|
| It's a really useful concept to keep in mind when designing or
| maintaining complex systems.
| MichaelZuo wrote:
| 'complex systems usually operate in a failure mode' has a
| somewhat different meaning from "complex system always operates
| in a failure state".
|
| They usually operate in a failure mode because it's easy to be
| deceived by the superficial appearances of complex systems,
| thus it seems like a big bother to drill down the layers, until
| a failure has occurred. As excellently demonstrated by this
| 'Factorio' player.
| [deleted]
| msluyter wrote:
| Thank you for introducing me to this rabbit hole. Here's a
| NYTimes article from 1976 -- note, many issues with the OCR,
| but still interesting and entertainingly written:
|
| https://www.nytimes.com/1976/12/26/archives/why-nothing-work...
| selestify wrote:
| Same author wrote an entire book, The Systems Bible, on the
| topic.
| pengstrom wrote:
| 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.
| Karellen wrote:
| One of the consequences of this is when something goes very
| wrong, and the people involved say it really shouldn't have
| because something like 4 separate things have to fail at the
| same time for that to have happened.
|
| What they don't realise is that, thanks to the FFT, 2 of
| those 4 things actually failed over a year ago and the system
| has been continuing to work ever since without anyone ever
| noticing. One of the other things actually fails
| intermittently a couple of times per month, and while a
| couple of people have noticed that and reported it, either
| it's not been investigated at all, or when it was
| investigated everything looked fine and the report was put
| down as an unexplained glitch. All that was actually needed
| was for the 4th thing to fail, to cause this "can't happen"
| failure mode to suddenly ruin everyone's day.
| salawat wrote:
| All of this is further exacerbated by the modern business
| take on capitalism of "optimize away work that doesn't
| positively produce".
|
| Just because you're paying someone to go check and they
| don't find anything 99% of the time, you don't get rid of
| that. If you do, there goes the pnly sensor capable of
| propagating that signal to the rest of the control network.
| Applies equally well in electronics/circuits/or human
| domains.
| EricMausler wrote:
| If only C-levels and Boards viewed such jobs as a good
| excuse to provide someone with a living as opposed to
| poor worker utilization hurting their bottom line
| chinabot wrote:
| 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.
| kbenson wrote:
| 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 things you can manually fix or ignore, and fit a
| frequency level you can live with.
|
| Until the stuff you're managing becomes too large for that to
| make sense anymore, because that only scales so far (but
| surprisingly far for diligent admins). Then you need to move
| to something more complex, which is a big job and requires an
| entirely different way of reviewing (like Prometheus). You're
| probably better doing that from the beginning, but it's time
| and effort but everyone can take, or may not have existed at
| that time.
| outworlder wrote:
| > 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
| history. K8s pod logs some data. That is eventually noticed
| by fluentd, which is watching the filesystem. Fluentd sends
| to our logging servers over the network. That goes to
| kafka, then is shipped to the system that actually does the
| indexing. And then, there's a query running, which will
| then count the number of times that string appeared and
| updates a counter.
|
| All of which could have been avoided if the apps just added
| +1 to a counter, and exposed that as /metrics so Prometheus
| could scrape.
| retzkek wrote:
| 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.
| renlo wrote:
| I don't know if we worked for the same company but your
| logging pipeline sounds almost identical to the logging
| pipeline at my last company. That said, logs are
| definitely abused often, usually all it takes is an
| engineer to say to themselves "well, I know this gets
| logged 1000x a second per host, but, someday during an
| outage I could potentially use this!", without realizing
| that one log call can cost thousands or more a month.
| Tools like ElastAlert unfortunately dont help in that it
| makes people comfortable using logs as a fail signal. It
| seems like the best way to get teams to limit their
| logging is to give them the exact dollar amount their log
| call costs; ie, "this one log line accounts for 5% of all
| log traffic, well that costs $X a month, and it's only
| been queried for N times"
| AndrewKemendo wrote:
| This is so spot on it's universally true
| rdoherty wrote:
| Also related: How Complex Systems Fail
| https://how.complexsystems.fail/
| TeeMassive wrote:
| The number of interactions of a system with n components
| increases according to O(n^2).
|
| The probability of an interaction _not_ going wrong decreases
| exponentially with each interaction.
| gyropop wrote:
| stavros wrote:
| Hmm, what does he mean "I woke up the next day"? Did he leave
| Factorio running, or did it get an online component while I
| wasn't looking?
| SmooL wrote:
| Probably left it running? I've definitely left my factory to
| idle to build up resources while I'm gone, when I'm playing on
| peaceful mode.
|
| You could also run headless version of the game on a server and
| just connect to it for the same effect.
|
| Remember - Factorio is just an idle game with extra steps.
| stavros wrote:
| Ah, makes sense, thanks.
| alephaleph wrote:
| *they, this is why they hate their tweets being posted here
| grimmn wrote:
| stavros wrote:
| pjc50 wrote:
| Go around your office using "she" to refer to your male co-
| workers and see how long before someone gets cross.
| stavros wrote:
| orf wrote:
| TobTobXX wrote:
| The chance you get the gender correct when you know the
| real name, the voice, the look and the behavior of a
| person is significantly higher. Thus it makes more sense
| to raise an eyebrow when someone misgenders in real life.
| ranger207 wrote:
| It's done by some people intentionally to be offensive, and
| it's impossible to tell if someone doing it is doing it as
| an insult or out of ignorance. And, believe it or not,
| there's enough people out there that do it intentionally
| that assuming ignorance would be incorrect more often than
| it'd be correct
| stavros wrote:
| Really? Huh, that's shitty.
| horsawlarway wrote:
| ClassyJacket wrote:
| spillguard wrote:
| Side note, does anyone know why the author has written "F*ctorio"
| instead of "Factorio"?
| drewtato wrote:
| https://twitter.com/Foone/status/1581662557470806017
| serf wrote:
| 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 and 'meeting down by the docks', I guess
| that's akin to what federated services offer?
|
| note : I find federated social networks to have the same
| flaw, it's my belief that good things should be archived and
| catalogued for the public good -- so I have a hard time
| getting behind the idea of federated spaces that are
| protected from archival efforts -- but I do acknowledge that
| curation of a group is one of the best ways to reduce
| harassment.
| fknorangesite wrote:
| > 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.
| [deleted]
| tksiden wrote:
| They don't teach that in college.
| [deleted]
| ben_w wrote:
| Reminds me of Jurassic Park (book, I think?); nobody realised
| that dinosaurs were loose and breeding, because the system was
| doing:
|
| if dinosaurs < expected { alert("escaped dino!"); }
|
| and nobody anticipated dinosaurs > expected
| dudeinjapan wrote:
| "Life, uh, finds a way." Dr. Ian Malcolm anticipated it, but
| the park science lackeys dismissed his idea.
| smugkot wrote:
| If I remember correctly, Malcom did nothing but harp
| endlessly about how the park was doomed to failure due to
| various vague non-sequiturs.
|
| All we know is that he predicted fence integrity would fail
| somehow. We don't know what else he predicted, maybe he just
| got that one right by chance. We don't know if Hammond
| changed the park after the paper to invalidate Malcom's
| reasons for predicting fence integrity failure; if he had
| done this, Malcom would be wrong despite having predicted
| fence integrity failure.
|
| We sent people to the fucking Moon _and_ brought them back
| home. I'll be damned if humans can't solve Jurassic Park.
| TillE wrote:
| Malcolm was an author surrogate for the purpose of going on
| weird abstract rants which were mostly nonsensical even
| before they injected him full of morphine.
|
| I vastly prefer reading books in general, but with Jurassic
| Park they really cleaned up a lot of rough edges in the
| movie. The kids are way less annoying too.
| outworlder wrote:
| That was one of the system's invariants.
|
| assert (dinosaurs <= expected)
| ezekg wrote:
| Spoiler alert! (lol)
|
| I'm in the middle of reading this book and I figured this would
| (finally) happen next chapter. I'll be looking forward to this
| pivotal moment.
| electroly wrote:
| This is why 4-20 mA is a common signaling standard in industrial
| automation. 4 mA means zero and 20 mA means one. 0 mA means
| _broken transmitter_!
| janpot wrote:
| or why we build a stop command with normal-closed contacts. a
| broken wire results in the same signal as a "stop" command.
| mauvehaus wrote:
| If you're doing three-wire control [0], it also means you can
| add additional "stop" buttons by wiring them all into the
| circuit in series.
|
| A nice-to-have addition to your table saw is a big red stop
| button you can reach with your foot so you don't have to take
| your hands off of your work pieces to shut the saw down if
| things have gotten more interesting than you expected them
| to. Three wire control makes this _super_ easy to add (once
| you 've found the big red mushroom-head n/c switch, of
| course).
|
| [0] https://twcontrols.com/lessons/control-wiring-3-wire-
| control...
| phkahler wrote:
| Semantics are really important in these situations. We have a
| system with an E-stop (emergency stop) circuit. Any break in
| the loop and the system will shut off. It needed to work
| together with one particular vendors board that insisted on
| having a "hardware enable" signal that it could control.
| Rather than adding an additional circuit, someone decided to
| have "hardware enable" flip a normally open relay in the
| E-stop circuit. Technically this "works" because enable
| clears the E-stop condition and allows the thing to function.
| From a practical point of view this has caused no end of odd
| problems, particularly when diagnosing issues where things
| fail because the meaning of this signal has been compromised.
| oasisbob wrote:
| This reminds me of what I've seen happen with the internal
| health-check endpoint often added to APIs. Simple at first,
| but eventually there are endpoints to cause the health-
| check to synthetically fail for deployment purposes; the
| health-check is also monitoring downstream dependencies;
| the health-check becomes much more and much less than it
| was intended to be.
| xani_ wrote:
| That's why in our monitoring we used nagios scheme + 1 (0 for
| invalid, 1 for ok, 2 for warning, 3 for crit, 4 for unknown)
| jallmann wrote:
| Also issue with golang (+ protobufs) where you can't
| distinguish a populated zero value from the default "not
| present" value.
| bazoom42 wrote:
| Thats why JavaScript has both undefined and null!
| kortex wrote:
| This drives me absolutely bonkers. We had a situation in a
| machine learning context where we should have been treating
| the output of a detector as NaN (it was deliberately opting
| out), but instead it was falling back to zero.
|
| Last I checked (this was years ago) the way to deal with this
| is to wrap it in a sub-message (which are actually nullable),
| which is just kinda gross.
| krackers wrote:
| I thought proto3 has support for optional scalar fields now
| (https://github.com/protocolbuffers/protobuf/releases/tag/v
| 3....), and proto2 always had it
| hedora wrote:
| It is also why white traffic lights no longer mean "go".
|
| White means "the red glass lens in front of the incandescent
| bulb shattered again".
|
| Related, from train signals:
|
| > _The invention of the track circuit in 1872 by William
| Robinson permitted automatic block signals. Most simply, a low
| voltage battery current runs up one rail and down the other. As
| long as current flows from the battery through one rail to the
| relay and back through the other rail, the relay remains
| energized and routes current from another battery to the green
| lamp of a clear signal. But when a train is present, the
| circuit is short circuited by the steel wheels and axles of the
| cars; a broken rail or an open switch will also break the
| circuit. As a result the relay is opened and the signal
| displays red. The system is arranged so the failure of any
| component results in a red indication or a dark signal (which
| must be interpreted as the most restrictive aspect that signal
| can display)._
|
| https://www.trains.com/trn/train-basics/abcs-of-railroading/...
| martyvis wrote:
| Similarly train brakes are failsafe. They operate by
| compressed air. Being connected to the locomotive and hence
| control allows them to be released. If the carriages become
| disconnected, brakes get applied.
| stewx wrote:
| We have white traffic lights now in Canada for "transit
| advance", when buses are allowed to proceed before the rest
| of traffic.
| qwezxcrty wrote:
| Also common in Europe (CH, D).
| fknorangesite wrote:
| Yes but it's also a different symbol - a vertical line
| rather than the full circle (at least in my experience).
| rkagerer wrote:
| Would they have breaks (gaps) to segment the track into
| distinct stretches of conductors?
|
| How far down the line would the supply voltage run (or how
| far away would a train complete the circuit) before
| resistance losses degrade the system?
| thaeli wrote:
| Yes, insulators were (and still are) used between track
| blocks.
|
| The maximum length of a block with this system (versions of
| which are still used today) varies greatly depending on
| local conditions. I've seen 2k to 10k feet as a general
| performance range.
| acdha wrote:
| Train air brakes are similar in failing safely for the same
| written-in-blood reasons:
|
| https://en.wikipedia.org/wiki/Railway_air_brake
| bombcar wrote:
| Some military trucks are designed the opposite way on
| purpose - because they'd rather have no brakes and be able
| to move than be stuck on the battlefield.
| driverdan wrote:
| Not in the US. US trucks are built using standard truck
| parts, including off-the-shelf air brakes that fail safe.
| m463 wrote:
| they didn't always fail safe.
|
| I remember a house at the bottom of a steep mountain
| grade that got plowed into on a regular basis especially
| during that time.
|
| EDIT: hmm... seems freezing might still be a way to cause
| failure?
| acdha wrote:
| That's a great example of how you always have to design
| for a context.
| bombcar wrote:
| Yeah, any design is going to be various trade-offs, and
| you have to understand them (and how they may relate to
| your mission) when determining what to do and what would
| be a bad decision.
|
| For example, cars have "fail open" brakes but have
| independent cylinders so that it is relatively hard to
| have _all_ four wheels fail at the same time (older cars
| had single master cylinders) - and one of the tradeoffs
| is that people want cars to get going immediately and not
| wait for brake cylinders to "charge up".
|
| As more and more things get computerized, you have more
| options for "intelligent failover" - anyone who used to
| drive an old manual car knew you could slow down using
| the engine - but now the computer could detect brake
| failure and do things for you to help recover.
|
| And as seen from other comments, the modern US military
| prioritizes "on-road safety" over "under ongoing attack
| ability" - partially because of changing strategies I
| suspect, but also from the realization that the US
| military kills more members of the US military each year
| via accidents, etc, than anything else.
| xani_ wrote:
| > For example, cars have "fail open" brakes but have
| independent cylinders so that it is relatively hard to
| have all four wheels fail at the same time (older cars
| had single master cylinders) - and one of the tradeoffs
| is that people want cars to get going immediately and not
| wait for brake cylinders to "charge up".
|
| And emergency brake that's wholly separate circuit.
| Gordonjcp wrote:
| Pretty much every car made since the 1980s has had dual-
| circuit brakes with usually one front and one rear wheel
| cylinder on each circuit. Volvo being Volvo took it
| further with their 2-series cars in the 1970s and 1980s,
| where the front discs had four-pot calipers configured as
| two sets of two-pot calipers. Each braking circuit had
| one half of each front caliper and one rear caliper, so
| in the event of one half of the brakes failing it would
| still stop in a straight line.
|
| You can use engine braking in automatic vehicles too, by
| simply changing to a lower gear.
| bombcar wrote:
| Yeah - but as we saw with the floormat/unintended
| acceleration, many people don't think of it in an
| emergency (all the fatalities could have been avoided by
| shifting into neutral in those cases, might have blown up
| the engine but wouldn't have crashed/killed).
| ddingus wrote:
| There is one subtle difference between automatic
| transmissions and manual ones and that is the manual one
| will allow a shift into a lower gear even when engine
| damage is likely.
|
| An automatic one will not, and will hold the current gear
| until car speed falls within shifting range.
|
| Ask me how I know :)
| bombcar wrote:
| Yeah, newer ones can be too smart for your own good (but
| not theirs) - older ones had no problem with you slamming
| it into reverse or park at freeway speeds - ask me how I
| know!
| nordsieck wrote:
| > Some military trucks are designed the opposite way on
| purpose - because they'd rather have no brakes and be
| able to move than be stuck on the battlefield.
|
| Do you have any details on that? Or a source I could
| read? I'm pretty curious now.
|
| I drove trucks in the military - specifically, FMTV,
| HEMTT, HMMWV, and 5 tons. None of them had the reverse
| brakes you describe.
| bombcar wrote:
| The deuce/half air-over-hydraulic brakes fail open (loss
| of air pressure leaves you with hydraulic brakes alone,
| loss of hydraulic leaves you with no brakes at all).
| However, there is a failure mode that leaves the brakes
| full on if the air cylinder jams.
|
| At the time it was an acceptable trade-off; later
| military vehicles have more in common with trucks than
| tanks, I suspect.
| thaeli wrote:
| Losing brake boost in a failure condition is the typical
| failure mode in most vehicles with hydraulic brakes. A
| hydroboost failure in modern medium trucks reduces
| braking performance just as much as an air pack failure
| in the deuce and is just as scary..
|
| The brakes, unboosted, are supposed to still be capable
| of stopping the vehicle. This is also why hybrid and
| electric vehicles with regenerative braking, that
| normally use brake-by-wire with a pedal feel simulator,
| fail through to using the PFS as a direct unboosted
| hydraulic cylinder.
|
| Losing all brakes in a hydraulic circuit failure is just
| because those trucks are so old they only have single
| circuit hydraulic brakes. Part of the A3 upgrades was
| changing over to a modern dual circuit hydraulic system.
|
| So basically, the issue is that medium trucks are in a
| weird in-between. Not heavy enough to require full air
| brakes, but heavy enough that some of the safety
| assumptions we make about light vehicles are potentially
| less true.
| invalidator wrote:
| That's one reason, but the big one is that it makes it easy to
| remote-power the sensors. It gives them a 4mA budget to Do
| Their Thing even when outputting a zero.
| Unklejoe wrote:
| Another example is how garage door opener trip-beams work (the
| sensors that detect if something is in the way before lowering
| the door).
|
| The transmitter and receiver are wired in parallel and
| connected to a power supply through a series resistor. When the
| receiver receives the signal from the transmitter, it pulls the
| supply voltage down, which then causes the transmitter to stop
| transmitting, which then causes the receiver to stop pulling
| the supply down, and the cycle continues. The end result is
| that if there's no obstruction, the supply voltage pulses and
| the system checks for this. If there's any other type of
| condition, the signal is either 0 or VCC. Basically, the system
| is designed so that false positives are extremely unlikely
| since that's the worst case scenario.
|
| There's some capacitors in the transmitter/receiver to control
| the frequency.
| Gordonjcp wrote:
| Gas central heating boilers use something similar to control
| the gas solenoid - the solenoid is fed through a biggish
| capacitor, which has a diode and a capacitor to "smooth" the
| pulses from the microcontroller. If the microcontroller
| output latches itself on, the capacitor charges fully, there
| are no more pulses, and the solenoid drops out.
| crgwbr wrote:
| Interesting. That makes sense, but what's the reason for using
| current instead of voltage as the variable?
| akelly wrote:
| High impedance (low current flow) signals are more prone to
| electrical interference. This is particularly bad when you're
| running long wires across a factory with big electric
| machines running. And if your signals are low impedance
| (significant current flow), then you get voltage drop across
| your long wire, so you can't use voltage-based signaling.
| tfigment wrote:
| 1-5 V is also common. You can convert between the 2 with a
| resistor.
| mschuster91 wrote:
| Current flow is independent of wire length, the sender only
| has to turn up the voltage high enough to overcome the wire
| resistance.
| adrian_b wrote:
| This happens because the real insulators are better
| approximations of ideal insulators, than real conductors
| are approximations of ideal conductors.
|
| In electrical circuits made with normal conductors and
| insulators, e.g. copper wires and organic polymer
| insulators, it is possible to ignore the currents that
| branch from the wires and close through the insulators,
| because they are extremely small (e.g. in the femtoampere
| range), but frequently it is not possible to ignore the
| voltage drops along the copper wires, which are caused by
| the resistances of the wires, and which may be in the
| millivolt range.
| BenjiWiebe wrote:
| You will also get voltage drops from the sensors using
| power along your current loop as well, no? Whereas
| current will be the same along the entire loop all the
| time.
| lisper wrote:
| I have a bachelors degree in electrical engineering and
| work experience in hardware design and in the back of my
| mind I've always known this to be true, but this is the
| first time in my life I've ever heard anyone say this
| explicitly. EE pedagogy is badly broken in places.
| freedomben wrote:
| Indeed, when discussing theory we love pretending that
| there's no voltage drop from the wires, which can really
| bite you when you get into design or deep failure
| analysis. All good technicians and engineers learn this
| reality fairly soon, and it's one of the things we check
| especially when dealing with indeterminate failures.
|
| As much as I love academia, I really wish there were more
| instructors with real experience that could say things
| like, "for math purposes assume a zero-loss conductor"
| while still emphasizing that real life is not so simple.
| deepspace wrote:
| Maybe it has to do with the culture at specific schools.
| As I mentioned in another comment, my instructors loved
| to include wire resistance in their problems, and always
| explicitly stated the zero-loss assumption when
| applicable.
|
| We did have a healthy incubation program, where
| instructors helped companies with product development, so
| perhaps that is what brought the real-world experience.
| deepspace wrote:
| As another EE, I had the opposite experience. Voltage
| drops due to wire resistance and transmission losses were
| drilled into our heads at any possible opportunity.
| hermitdev wrote:
| Difference between focusing on digital vs analog, maybe?
| As another EE, I vaguely recall this being pounded into
| us more in power systems than any of my digital
| electronics courses.
| mschuster91 wrote:
| > EE pedagogy is badly broken in places.
|
| Generally, the biggest problem with math, physics and
| chemistry is that if you miss just _one_ lesson (no
| matter if you physically miss it, or in worst case miss
| out understanding a concept for a couple minutes), you
| can easily end up "left behind" for _years_. With
| history, arts, languages, a number of computer science
| topics or most of biology you can either skip out on a
| certain subject or catch up easily on your own, but not
| getting a specific part in math /physics/chemistry and
| lacking the resources to follow up is setting oneself up
| for _exponential_ learning gap later on.
|
| The societal problem is that we've not set up schools or
| universities to deal with this "failure mode". Privileged
| kids can have after-school teaching or siblings helping
| out, but most will sooner or later resign and hate these
| subjects for the rest of their lives - and that is
| incredibly sad.
| sjruckle wrote:
| Also, there's greater immunity to interference and poor
| connections.
| SnowHill9902 wrote:
| Charge is conserved whereas voltage (i.e. electric field
| differential) is not.
| mananaysiempre wrote:
| Also why a standard keyboard has a Break key: used to be that a
| telegraph station would have a bell that rang if it detected a
| broken connection (a "break condition"), then people figured
| that deliberately inducing a break was a handy way to alert the
| remote operator. I think the first automated telegraph systems
| actually used current-loop signalling, but I'm not sure about
| the first _practical_ ones; in any case, the concept carried
| over into modern (well, 70s-vintage) asynchronous lines--most
| UARTs nowadays have a break interrupt that you can enable.
| sneak wrote:
| I have a standard keyboard and it has no break key.
| mananaysiempre wrote:
| To clarify, by a "standard" keyboard I mean a (usually US)
| QWERTY PC keyboard with 101 to 105 keys (depending on the
| amount of Win/Super and Menu keys and the presence of an
| additional punctuation key to the left of Z). Those have
| three rows of three keys each above the arrows (not
| counting any "media keys" such as Power); the topmost one
| of those is PrintScreen / SysRq, Scroll Lock, and Pause /
| Break, though some of those labels may be omitted. I
| honestly have never seen a full-size PC keyboard without
| those. (How am I supposed to hit Ctrl-Break or Win-Break
| otherwise?)
|
| Strictly speaking, there is no Break key in the same sense
| that there is no SysRq key--there are only special Break
| and SysRq scancodes that AT and PS/2 keyboards send instead
| of Pause and Print Screen when Ctrl or Alt respectively is
| depressed (thus the combined labels), while USB keyboards
| don't even have those, they just send normal modifier
| sequences. But I don't think that's what you had in mind :)
| sneak wrote:
| I know what you meant. I was implying that a 101-105 key
| keyboard has not been standard for a decade or more.
|
| I would be willing to bet that none of the ten most
| popular/best-selling computers in the country for the
| last 5-10 years have had a key that says "break".
| cafeinux wrote:
| It's also named "Pause key", but one could argue that if
| your keyboard doesn't have any of these two keys, it cannot
| really be called "standard".
| [deleted]
| peterleiser wrote:
| Alarm systems use the "End of Line" resistor concept. The alarm
| triggers when a sensor is opened and current flow stops. Closed
| is ambiguous because it could mean power is flowing through all
| closed sensors OR there is a short (alarm panels handle
| shorts). A resistor allows the panel to consider 0 Ohms a short
| and some specific number of Ohms as closed and working. It
| apparently also provides a way to detect tampering of the
| wires.
|
| https://www.alarmsystemstore.com/pages/all-about-resistors
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