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Why Do Computers Still Crash?

geoff lane asks: "I've used computers for about 30 years and over that time their hardware reliability has improved (but not that much), but their software reliability has remained largely unchanged. Sometimes a company gets it right -- my Psion 3a has never crashed despite being switched on and in use for over five years, but my shiny new Zaurus crashed within a month of purchase (a hard reset losing all data was required to get it running again). Of course, there's no need to mention Microsoft's inability to create a stable system. So, why are modern operating systems still unable to deal with and recover from problems? Is the need for speed preventing the use of reliable software design techniques? Or is modern software just so complex that there is always another unexpected interaction that's not understood and not planned for? Are we using the wrong tools (such as C) which do not provide the facilities necessary to write safe software?" If we were to make computer crashes a thing of the past, what would we have to do, both in our software and in our operating systems, to make this come to pass?

67 of 1,224 comments (clear)

  1. Simple ... by Vilim · · Score: 4, Insightful

    Well, basically as software systems get more complex there is more things to go wrong. That is why I like the roll-your-own-kernel of linux. Don't compile the stuff you don't need and fewer things can break.

    --
    History will be kind to me, for I intend to write it - Sir Winston Churchill
    1. Re:Simple ... by Transient0 · · Score: 4, Insightful

      More specifically... As hardware gets more complex, software gets more complex to fill the available space. More complex software not only means more things to go wrong but also means that the hardware never really gets a chance to outpace the needs of the software.

      Also, as I'm sure someone else will point out, it is very hard to right code that will not crash under any circumstances. Even if you are running a super-stripped down linux kernel in console mode on an Itanium, you can still get out of memory errors if someone behaves rudely with malloc().

    2. Re:Simple ... by cscx · · Score: 4, Funny

      Actually the Zaurus he mentions crashing in the article runs a roll-your-own Linux kernel... ;)

    3. Re:Simple ... by The+Analog+Kid · · Score: 5, Interesting

      Yes, on my parents computer, which has 2000 on it(tried Linux it didn't work for them). I set most of the services to manual that aren't needed. Disabled Auto-update. Put it behind a router ofcourse. The only problem remained was Internet Exploder, well I just installed Mozilla with an IE theme, haven't noticed a difference). I think killing most of the services keeps it up. Haven't had a problem with it. This was done before KDE 3.1.x so who knows Linux might work after all.

    4. Re:Simple ... by orbbro · · Score: 5, Funny


      And, when the cocaine that let's YOU do all these things wears off, you'll crash!

      --
      "It's an erotic, spectacular scene that captures the thrusting, violent, vibrant world Bohemian spirit..."
    5. Re:Simple ... by fishbowl · · Score: 5, Insightful


      "However, if I'm trying to download a huge file while opening and closing lots of windows, programming some web pages, uploading them to the web, listening to some tunes, talk to 80 different people on AIM, and enjoying a flash animation at the same time, the computer might crash."

      Was it, or was it not, designed to be used in this way? If it was not, why does the system let you try it?

      --
      -fb Everything not expressly forbidden is now mandatory.
    6. Re:Simple ... by DarkZero · · Score: 5, Insightful

      Was it, or was it not, designed to be used in this way? If it was not, why does the system let you try it?

      Your microwave isn't designed to let you put an AOL CD or a piece of tinfoil in it and turn it into a box-shaped firecracker, but it still lets you try it. So the simple answer would be that it lets you do it because it can't control absolutely everything that it interacts with. A download manager isn't designed to be run at the same time as an MP3 player, AIM, ten browser windows, an IRC client, and downloads in other programs at the same time, but it still lets you try it because it has no control over those programs, no different than the microwave's lack of control over your hand and your AOL CD.

  2. Easy by PerlGuru · · Score: 4, Funny

    Same reason cars crash.... people ;-)

  3. Whose computers still crash? by fishbowl · · Score: 4, Funny

    Crash? What crash?

    radagast% uptime
    8:56pm up 582 day(s), 12:45, 22 users, load average: 0.00, 0.00, 0.01

    --
    -fb Everything not expressly forbidden is now mandatory.
    1. Re:Whose computers still crash? by Anonymous Coward · · Score: 5, Funny

      load average: 0.00, 0.00, 0.01

      easy to keep a computer up if you never use it ;)

    2. Re:Whose computers still crash? by toddestan · · Score: 5, Informative

      Even with my uptime experiments, which consisted of taking an old but reliable hardware, installing Windows 95/OSR2/98/98SE/ME, and then letting the computer idle and do nothing never resulted in more than about 25 days before I came over and windows was fubar'ed or the computer was simply locked hard.

      Windows 3.1 actually did quite well if I remember right, as it seemed perfectly content sitting idle doing nothing seemly forever. Windows 9x always seemed to randomly thrash the HDD, even after a clean install, which led me to believe that Windows 9x is never truly idle, it's always up to something (virtual memory?), and that something eventually will bring it down.

      Windows 9x actually has a bug in it that would lock the computer after 46 days of uptime, but it took years to catch it because no one ever got close to that mark.

    3. Re:Whose computers still crash? by UserGoogol · · Score: 5, Funny

      Well... in my day I had to write games with just seven transistors and a piece of cheese! And I thought I was lucky. Kids today. Geez.

      Granted, I'm 16, but that's not the point.

      --
      "Never attribute to malice that which can be adequately explained by stupidity." -- Hanlon's Razor
    4. Re:Whose computers still crash? by Dr.+Photo · · Score: 5, Funny

      Reboot? What reboot?

      Now, when was the last time you tested those init scripts? :)


      Init scripts? You heathen!!

      Rebooting is a special occasion, signalling the coming of the harvest season, or the installation of a new kernel. Accordingly, the High Priest shall bring the system up by hand, typing in the ancient incantations from the sacred scrolls.

      Init scripts are for the weak of faith. Let ye not be tempted by the daemons of rc-dot-d!

    5. Re:Whose computers still crash? by Guppy06 · · Score: 5, Funny

      "Accordingly, the High Priest shall bring the system up by hand, typing in the ancient incantations from the sacred scrolls."

      Would those sacred scrolls, perchance, be small, yellow, and stuck all around the monitor screen?

    6. Re:Whose computers still crash? by fucksl4shd0t · · Score: 4, Funny

      Kind of like how my 2 year old daughter carrying dishes to the sink. She's trying to be helpful, but occasionally she drops one.

      HEh. My daughter's 4 and she's never accidentally dropped a dish. That doesn't mean she's never broken one, though....

      My son's two, and it's impossible to tell if he drops dishes on purpose or on accident, because he does it so much.

      Should've named my daughter Linux and my son Windows. Now we're having another one, what should I name him? BSD? What's he gonna do? Sit there and whine about how nobody loves him 'cuase he's the only true eunich left? Or is he gonna spend his time crying because right after he's born they're gonna cut him into three pieces and each person will claim their piece is better than the whole?

      Wow, first time I've ever trolled BSD. I feel strangely liberated...

      --
      Like what I said? You might like my music
  4. AS LONG AS YOU CAN TEST EVERY STATE... by drink85cent · · Score: 5, Insightful

    As I've always have heard with computers you can't prove something works, you can only prove it doesn't work. As long as there are an almost astronomical number of states a computer can be in, you can never test for every possible case.

    1. Re:AS LONG AS YOU CAN TEST EVERY STATE... by innosent · · Score: 5, Insightful

      Not exactly. Assuming that the hardware is ok, you can prove that a system is reliable for any given finite input (including, most importantly, all possible finite substrings of inputs, however it is not possible to test all possible inputs, since a portion of those are infinite), it's just that doing so in large systems takes enormous amounts of time, and of course, time = money. Take Microsoft, for example. It takes a team years to develop a product like Windows XP, run a few test cases, and fix the major bugs. But just think how long it would take to go through every possible input substring of a given length (and by substring/string I am including non-character inputs [mouse, network, etc]).

      Consider a simple program that inputs 10 short strings of text and does some computations on those strings. Say for example that the system that has only a keyboard as input, that all input functions are guaranteed only to input A-Z (caps only), the space bar, and 0-9 (regex ((A-Z)*(0-9)*)*( )*), not to overflow, and that there are 10 inputs with exactly 10 characters for each input (spaces fill end of string). This means that there are 37 possibilities for each digit, totaling 37^100 unique possible inputs, about 6.61E156 possibilities, each 100 characters. Typing a million characters per second would take 2.094E145 years! Keep in mind that this is an extremely simple system.

      Therefore, it is not possible to test ALL input cases of any nontrivial program, only a few selected cases, which most will agree is far from proving a program correct. Instead, developers should have detailed mathematical descriptions of how a program is to behave at each incremental step, and verify that the program follows those descriptions accurately. Programs can only be proven correct in the same manner that any discrete mathematic concept can be proven correct, with one of the most common methods of a functionality proof being mathematical induction. Based on a few basic assumptions (like that the functions you call work as documented), the rest of the system can be proven by proving the trivial parts and cases first, and then constructing a complete proof based on the trivial parts.

      The problem with this is that a small change can have a big impact on the proof, and nobody actually takes the time to verify that everything still works. Companies don't often spend money on making their software 100% correct, they just need to add the nifty new features that their customers want before their competitors do. I'd be willing to bet that 90% of the bugs found in XP can be traced to a "nifty new feature" that broke code that may have been proven correct at some point.

      In other words, the short answer is yes, if you can test every state, you can prove a program correct, but since that's usually impossible, it becomes the developers' responsibility to incrementally prove the system, which is far easier if all functionality is planned ahead of time, but still too time/money consuming for most software companies to bother with. Microsoft doesn't care if your computer crashes, you'll probably still pay them, and as much as I'd like to think otherwise, OSS isn't much different (although it's usually more time than money there).

      --
      --That's the point of being root, you can do anything you want, even if it's stupid.
  5. Human Error by Obscenity · · Score: 5, Insightful

    All programs (for the most part) must be written by people. People crash, they're buggy and they dont have a development team working on them. Computers crash because people cant catch that one little fatal error in 10,000 lines of code. Smaller programs are less succeptable to errors and big scary warning messages that make even the most world-hardend geek worried about his files. Yes, it's getting better with more and more people working on something at once. Mozilla (www.mozilla.org) has a feedback option to help them debug, many software companies are including this. But even with that in place, there is always that small human error, that will screw something up.

    --
    OMG OMG OMG WTF OMG WTF BBQ STFU RTFM, OMFG OMG OMG OMG ROFL LMAO OMG WTF STFU ROFLMAO
    1. Re:Human Error by Malcontent · · Score: 5, Insightful

      "People crash, they're buggy and they dont have a development team working on them. Computers crash because people cant catch that one little fatal error in 10,000 lines of code. "

      While this statement is true it's also a cop out. In the last twenty years there have been tremendous amount of advances in computer science and languages and yet everybody still programs in C.

      That is the reason why programs crash. Why don't people use languages that make programs more failsafe and make programmers more productive.

      It would be interesting to do a study of the "bugginess" of programs written in python, java, scheme, smalltak, lisp etc. My guess is that programs written in C crash the most.

      Where are all the programs written in scheme or smalltalk or ML?

      Use better languages and crash less.

      --

      War is necrophilia.

    2. Re:Human Error by Uller-RM · · Score: 4, Insightful

      Java programs can still crash -- and believe me, grade homework for undergrad CS students for a few years and you'll see plenty of it. The only difference is that Java tosses an exception that isn't handled, and C either asserts and calls exit(-1) or segfaults.

      I don't think it's fair to say that any one language is "safer" than another -- once you reach a certain level of expertise, one can write a stable and robust program in C or C++ or Java or Haskell (my preference) with equal effort. The effort is mental: being persistent enough to define solid logical definitions for each part of the program, failure conditions, etc. and then execute them to the letter in the language of choice. If the program behaves logically, you can prove that it works using logical principles -- induction and so on. (And if you ever do govt contracting or any other project that calls for requirement tracability, you'll need to.)

      The difference between languages is merely the way the code is expressed. Java and C++ have exceptions; C does not. For some situations, return codes are better than exceptions, and for some situations the opposite is true. Java has robust runtime safety -- C and C++ do not. C and C++ have templated containers -- Java's just now getting such genericity. All languages and all approaches to problems have tradeoffs: the mark of a good programmer is knowing those tradeoffs and picking which is best for the situation.

    3. Re:Human Error by JohnsonWax · · Score: 4, Interesting

      "All programs (for the most part) must be written by people. ... Computers crash because people cant catch that one little fatal error in 10,000 lines of code."

      All bridges (for the most part) must be built by people. Bridges collapse because people can't catch that one little fatal error in one or two million components.

      The shit coders put out there, I swear... The reason software crashes is that by-and-large it's hacked together, not engineered. You hack a bridge together, and yes, it'll fail. You engineer software, and yes, it will run reliably. It's not fun to do - no easter eggs, no cool tricks, no cramming features in weeks before ship.

      I'm stunned at the amount of code that goes out that was written by interns, by unexperienced coders, by people that just don't have a clue. The software industry really has no concept of best practices, no leadership, no authority body. The fact that buffer overflows still happen is stunning.

      It's not small projects that work well because out of dumb luck they happen to not fail, or larger projects that work okay because we have 34,000 people looking at the code. If that's 'best practices', then we're doomed.

      "Mozilla (www.mozilla.org) has a feedback option to help them debug, many software companies are including this."

      Uh huh. Let's translate that to my car: "Hi. Yeah, I'd like to report a bug. I have a Saturn Ion, version 1.1v4. Yeah, when I turn on the left turn signal and then turn on the lights, the car catches on fire. You might want to fix that in the next version. Just though you might want to know. Bye."

    4. Re:Human Error by GlassHeart · · Score: 4, Insightful
      It would be interesting to do a study of the "bugginess" of programs written in python, java, scheme, smalltak, lisp etc. My guess is that programs written in C crash the most.

      Even that is a worthless statistic. Assuming that bad programs are written by bad programmers, the language that more bad programmers choose will appear the highest in your study as the buggiest language. Bad programmers choose the language du jour, thinking it will land them a cushy job.

      You'll have to disprove the assumption to correctly blame the language.

      Use better languages and crash less.

      Try dividing by zero in your better language of choice.

    5. Re:Human Error by ojQj · · Score: 4, Insightful
      Disclaimer: I haven't programmed in Java since my undergrad, but I learned it before C++. I've been programming in C++ professionally for 3 years straight now, not counting internships and class assignments before that.

      I'd rather have an exception than a crash. It gives me more information about what I did wrong. A crash that's not reliably repeatable and only happens in your release version under Windows OT systems with IE 4 installed, is next to impossible to find and fix -- in C++ it's only worse.

      Not only that, but memory management is more than just a nuisance. Just yesterday, I wanted to move some code from one class to another to improve the object-oriented structure of some code which I've taken over from another developer. In that code were a couple of news, and I couldn't find the deletes which matched them. So I asked the original developer. Turns out the deletes were in a base class of the class that I was moving the code to. If I had been programming in Java, this would have been a cut and paste job finished in 30 seconds, plus 15 minutes for testing the change before checking in. In C++, it was 15 minutes trying to find the deletes myself, 15 minutes waiting for the other developer to get to a break point in his work and another 15 minutes assuring myself that the deletes really were called for all cases, and another 15 minutes for testing the change before checking in. That's a factor of 3-4 (depending on if I have something else I can do while waiting) for the C++ program.

      Memory management and other unnecessary tasks which C++ saddles the developer with do make an impact on either development time, program stability, or both. And that is also true for experienced C++ programmers.

      They also make an impact on language learning time, which is not to be underestimated with the number of newbies today, and people moving up from still worse languages like Cobol. In addition, even for an experienced C++ programmer, they make a difference in the time it takes to understand code which was programmed by another programmer.

      I agree with you that there are situations where every language, including C++, is the most appropriate for the problem in question. I just think that C++ is over-used, thus reducing the average stability of modern programs and the average productivity of modern programmers.

  6. In my CompSci class.. by ziggy_zero · · Score: 4, Insightful

    ...I remember my teacher saying "Computers do exactly what they're told, not necessarily what you want them to do."

    I think the root of the problem is time. Microsoft doesn't have the time to spend going through every possible software scenario and interaction, or every possible hardware configuration. If they did do that, it would probably take a decade to pump out an operating system, and by that time hardware's changed, and it's a neverending cycle.....

    We just have to accept the fact that the freedom of using the hardware components we want and the software we want, all made by different people, will result in unexpected errors. I, for one, have come to grips with it.

    --
    I belong to the ______ generation.
    1. Re:In my CompSci class.. by KrispyKringle · · Score: 4, Funny

      And just when being into computers was starting to get "cool" (think The Matrix, Hackers, or Swordfish) someone like you comes along and start talking about Dungeons and Dragons. There go my chances of getting laid. There go all our chances of getting laid.

  7. because someone was very curious and decided to... by null-sRc · · Score: 4, Funny

    *0;

    never follow the null pointer they said... what are they hiding there????

    --
    -judging another only defines yourself
  8. Reliability and complexity by woodhouse · · Score: 4, Insightful

    Because reliability is inversely proportional to complexity. Systems these days are generally a lot more complex than those of 10 years ago, and in complex systems, bugs are much harder to find. The fact that you say stability hasn't changed is in fact a pretty impressive achievement if you consider how much more complex hardware and software is nowadays.

  9. It's not the need for speed by Jeremi · · Score: 5, Insightful
    It's the need for new features. Every feature that gets added to a piece of software is a chance for a bug to creep in.


    Worse, as the number of features (and hence the amount of code and number of possible execution paths) increases, the ability of the programmer(s) to completely understand how the code works decreases -- so the chances of bugs being introduced doesn't just rise with each feature, it accelerates.


    The moral is: You can have a powerful system, a bug-free system, or an on-time system -- pick any two (at best).

    --


    I don't care if it's 90,000 hectares. That lake was not my doing.
    1. Re:It's not the need for speed by WasterDave · · Score: 5, Insightful

      Thank you, at least somebody got it fucking right.

      Software doesn't have to crash, but for a given quantity of development resources there's a fairly simple tradeoff between feature-richness and stability.

      You want reliable? Strip back features left right and centre, design an elegant architecture, then unit test properly.

      Dave (in a ranty mood)

      --
      I write a blog now, you should be afraid.
  10. Don't forget the hardware... by MightyTribble · · Score: 5, Insightful

    Some crashes aren't the fault of the OS. Bad RAM, flaky disk controllers, CPU with floating-point errors (Intel, I'm looking at *you*. Again. *cough* Itanium *cough*)... all can take down an OS desite flawless code.

    That said, some Enterprise-class *NIX (I'm specifically thinking of Solaris, but maybe AIX does this, too) can work around pretty much any hardware failure, given enough hardware to work with and attentive maintainence.

  11. Touchy subject by aarondyck · · Score: 5, Interesting

    I remmeber years ago having a conversation with an IT manager at IBM. We were talking about the inability of computer programmers to make their code foolproof. His point was that we don't see problems like this with proprietary hardware. When was the last time someone crashed their Super Nintendo? Of course, with a PC platform (or even Mac, or whatever else) there are problems of unreliability. His idea is that this is because of sloppy programming. The reason we were having this conversation is that I had a piece of software (brand new, I might add) that would not install on my computer. You would think that a reputable software company (and this was a reputable company) would test their product on at least a few systems to make sure that it would at least install! The end result was that I ended up never playing the game (not even to this day), nor have I purchased another title from that company since that time. Perhaps that is the solution to the root problem?

  12. Scientific American... by Hanji · · Score: 4, Interesting

    Scientific American actually had an article on a similar topic. Basically, they seem to be accepting crashes as ineveitable, and were focusing on systems to help computers recover from crashes faster and more reliably...

    They also propose that all computer systems should have an "undo" feature built in to allow harmful changes (either due to mistakes or malice) to be easily undone...

    --
    A Minesweeper clone that doesn't suck
  13. Complexity, my dear Watson by T5 · · Score: 5, Insightful

    It's all about the bits. There are just so many more of them now, and a great deal more pressure in the marketplace to bring ever newer software and hardware to market. Back in the day of the IBM 360 and the VAX, even though we were mesmerized by the capabilities of these machines, they were years and years in the making, debugged much more thoroughly than we can hope for today, and much, much simpler.

    And let's not forget that this was the exclusive realm of the highly trained engineer, not some wannabe type that pervades the current service market. These guys knew these machines inside and out.

  14. Essence of Software Engineering by Zach+Garner · · Score: 5, Insightful

    Read "No Silver Bullet: Essence and Accident of Software Engineering" by Brooks. A copy can be found here.

    Software is extremely complex. Developed to handle all possible states is an enormous task. That, combined with market forces for commercial software and constraints on developer time and interest for free software, causes buggy, unreliable software.

  15. Microsoft by eht · · Score: 5, Insightful

    Microsoft has made an extremely stable OS, it's called Windows 2000, as long as you use MS certified drivers the OS should never crash, individual programs may crash under Windows, but you can hardly blame Microsoft for that. I have had Windows machines with months of uptimes and no problems, went down 8 days ago due to power failure too long for my UPS's to handle, which also took down my FreeBSD machines, uptime is matched for all of them, and will one day again be measured in months.

    Yes I should probably patch some of my Windows machines, but I have my network configured in such a way that for the most part I don't need to worry and you don't have to worry about my network spewing forth slammer or other nasty junk.

    1. Re:Microsoft by VTS · · Score: 5, Interesting

      Some time ago I would have agreed with you, but not anymore, If media player crashes playing some video then the whole system becomes unstable and then even doing something like sending a file to the recyclebin freezes the UI...

      --
      --- No 16-bit support in Vista? Half of our modules still use it! ---
    2. Re:Microsoft by CognitivelyDistorted · · Score: 4, Interesting

      Yes, NT5+ is very stable. MS is working on the driver problem. SLAM is a tool for verifying drivers. Given a requirement, e.g., after acquiring a kernel lock the driver must release it exactly once on all control paths, and some driver source code, SLAM can find all the ways the driver can fail the requirement. They have specifications for various driver types and are using them to test some drivers. It's a research project by the Software Development Tools group in MSR, but they're working on getting it stable and powerful enough to verify more drivers. If they can get it to work well enough, they'll supply it to hardware vendors.

  16. Economics? by iso · · Score: 5, Insightful

    While it's not the whole story, something definitely has to be said about the fact that while people are willing to pay for features, they're rarely willing to pay more for stability. Quite frankly there's little economic incentive to make software that doesn't crash.

    If your market will put up with the ocassional crash, and never expects software to be bulletproof, why bother putting the effort into stability? Until people start putting their money into the more stable platforms, that's not going to change.

  17. The ultimate solution by dsanfte · · Score: 4, Interesting

    The ultimate solution to the problem is to let computers write the software themselves. Give them a goal, set up evolutionary and genetic algorithms, and let them go at it on a supercomputer cluster for a few months.

    Of course, you'd need to make sure the algorithms that humans wrote aren't flawed themselves, but once you got that pinned down, you would be more or less home-free.

    Even if you didn't take this drastic a step, another solution would be computer-aided software burn-in. Let the computer test the software for bugs. A super-QA Analysis if you will. Log complete program traces for every trial run, and let the machine put the software through every input/output possiblity.

    --
    occultae nullus est respectus musicae - originally a Greek proverb
    1. Re:The ultimate solution by Jeremi · · Score: 5, Interesting
      The ultimate solution to the problem is to let computers write the software themselves. Give them a goal, set up evolutionary and genetic algorithms, and let them go at it on a supercomputer cluster for a few months.


      That only works if you can write a fiteness algorithm that can tell whether the program did the correct thing or not -- otherwise, you have no way to decide what to "breed" and what to throw away. And for many types of program, that fitness algorithm would be more difficult to write than the program you are trying to auto-generate...


      Of course, you'd need to make sure the algorithms that humans wrote aren't flawed themselves, but once you got that pinned down, you would be more or less home-free.


      All you've done is replace a hard problem ("write a program that does X") with a harder problem ("write a program that teaches a computer to write a program that does X"). No dice.


      Even if you didn't take this drastic a step, another solution would be computer-aided software burn-in. Let the computer test the software for bugs. A super-QA Analysis if you will. Log complete program traces for every trial run, and let the machine put the software through every input/output possiblity.


      For most modern programs, there isn't nearly enough time left before the heat-death of the universe to do this. Hell, for programs other than simple batch-processors, the number of possible input and outputs is infinite (since the program can do an arbitrary number of actions before the user quits it)

      --


      I don't care if it's 90,000 hectares. That lake was not my doing.
  18. Re:Not always the softwares fault: by Jeremi · · Score: 4, Insightful
    I've found in my years of repairing pc's that the majority of software problems have their root cause in hardware.


    Wow, your experiences are much different from mine, then. I'd say 95%+ of my computer problems are caused by software bugs.


    Software errors are repeatable. The exact same situation should produce the exact same error.


    For a significant percentage of software errors, that statement is false (at least misleading), because it's nearly impossible to reproduce "the exact same situation". For example, take any multithreaded program with a race condition bug -- the chances of the two threads getting the exact same time-slices on two different executions of the program are approximately zero. The result: a crash that happens only sometimes, at random, even given the exact same starting conditions.

    --


    I don't care if it's 90,000 hectares. That lake was not my doing.
  19. For those who are willing to pay... by PseudononymousCoward · · Score: 5, Insightful

    The number of bugs is smaller. Think of the systems used by the telcos, or NASA. Are they perfect? No, but they are much, much more stable than Win32, or Mac, or Linux. The reason is simple, the owners demand them to be.

    There are costs associated with fixing bugs and reducing crashes. The more stable an operating system is to be, the more time and money that must be devoted to its design and implementation. PC users are not willing to pay this amount for stability, either in explicit cost, or in hardware restrictions or in trade-offs for other features.

    As Linux evolves over time, its stability will always improve, but it may still never reach the stability of, say, VMS. Why? Because even with the open source model of development, there are still tradeoffs to be made, tradeoffs between new features and stability, mostly. And successive bugs are harder and harder to fix, requiring greater and greater amounts of time. At some point, the community/individual decides that they would rather spend their time going after some lower-hanging fruit.

    Just my $0.02

    Actually, IAAE.

    1. Re:For those who are willing to pay... by dghcasp · · Score: 4, Interesting
      Think of the systems used by the telcos, or NASA. Are they perfect? No, but they are much, much more stable than Win32, or Mac, or Linux. The reason is simple, the owners demand them to be.

      This reminds me of a story I read in the internal magazine of a telecomunications equipment supplier that I used to work for. It was about an international toll switch somewhere in the U.K. that had been up for 17 years (or something extreme like that.) Furthermore, this included having all of its hardware upgraded and replaced. Twice.

      Just stop and think about that for a while in PC terms... "I replaced my motherboard with the power on without rebooting my system, while it was serving 10,000 web pages a second."

      Granted, this is a higher level of hardware with full redundancy, but it still boggles my mind.

  20. Mandate memory checking tools by hawkstone · · Score: 5, Interesting

    I'm sure it's harder to accomplish this for kernel level code (it's primarily OSes being pointed at right here) but you can think everything is working hunkey-dorey and not realize something is going wrong under the covers.

    Most errors of this can be found with testing under tools like valgrind or Rational's purify. I'm sure there are others (I've heard of ParaSoft Insure++, ATOM Third Degree, CodeGaurd, and ZeroFault), but the quality of these tools really matters.

    The issue is that tiny errors can cause crashes intermittently, and not immediately. For example:
    uninitialized memory reads -- usually not a problem, but if this value is ever actually used, it will be.
    array bounds reads -- never acceptable, but depending on the structure of memory, may not always cause an immediate crash.
    array bounds writes -- like ABRs, may not be immediately fatal, but these are going to crash your code sooner or later.

    Since they don't always cause an immediate crash, these errors are likely to creep in to released code without use of one of these tools. And if you want to know why we shouldn't always run programs in an environment that checks these kinds of things, try it once; you'll notice a speed hit of usually an order of magnitude. C/C++ is a perfectly acceptable language -- not all debugging has to be done by the compiler/interpreter or only after you notice a problem.

    Anyway, hope that wasn't too pedantic....

  21. Obligatory anti-MS by cptgrudge · · Score: 5, Insightful
    Of course, there's no need to mention Microsoft's inability to create a stable system.

    What exactly is the purpose behind this? Why was it put in here? People are going to need to grow up if people in "our" circle want to be taken seriously. I've used Windows 2000 and Windows XP both. They crash as much as my Red Hat and Debian boxes do. Never. They are all rock solid.

    I work for a public school system. We have a class at the High School that teaches and certifies for A+ (I know, I know). They have all sorts of problems getting stuff to work and to get a system stable. In Windows and Linux.

    It isn't because they are high schoolers.

    It isn't because they are "just learning".

    It's because they buy really shitty hardware. They look for the best cost, and they get their hardware from some loser manufacturer that has fucked up drivers and horrible quality control.

    Properly maintained boxes with quality hardware in them just don't crash anymore. Programs maybe, but not systems.

    Christ, people, this has been beat to death! Microsoft has a great product for an OS now! Get back to making something better than them instead trying to convince yourself that Microsoft is delusional.

    Mod me Flamebait, I don't care.

    --
    Qualitas edurus commercium, nullus penitus net rimor, nullus deus beneficium
  22. A lesson from history by Dr.+Bent · · Score: 5, Insightful

    Back in the Middle Ages, when the Catholic Church wanted a Cathedral built, they would pay a bunch of Freemasons to do it. The Freemasons viewed themselves as creative artisans, and they closely guarded the secrets they used to construct these impressive houses of worship.

    The method they used, however, was less than impressive. Typically, they would start with a general design, and piece together stone and mortar until something collapsed, which happened quite often. Then they would patch the section that collapsed and keep on going until something else fell down, or they finished. Given the level of understanding with regards to Physics and Material Science, those Freemasons has no other choice than to build them this way.

    Now fast forward to the 21st century. The engineering disasters on par with those medieval collapses can be counted on one hand (Tacoma Narrows Bridge and the Hyatt Regency walkway collapse are the only two I can think of). This is directly due to the fact that a civil engineer can determine if a design is structurally sound before they build it.

    Contrast this with modern day software development. We can't even tell if a system is flawed after we build it, let alone before. So software gets written, deployed, and put into the marketplace that has no assurances whatsoever of actually doing what it's supposed to do (hence the 10,000 page EULA).

    You can't have Civil Engineers until you have Physics. And you won't have 100% bulletproof software until you have Software Engineering. And you won't have that until someone can figure out a way to prove that a given peice of software will perform as it's supposed to. JUnit is a step in the right direction, but there's still a long way to go. It's going to take a breakthrough on the order of Newton to make Software Engineering as reliable a discipline as Civil Engineering.

  23. Simple, yes, for other reasons by jabber01 · · Score: 4, Insightful

    Software crashes because it's complex, yes, but that's just part of it.

    Jets are complex too. So is the Space Shuttle. Cruise ships. CARS are pretty complex.

    While all these things do suffer catastrophic failure from time to time, it is far from the norm. Defective cars get recalled. Space shuttles ALL get grounded at the mere possibility of defect.

    If Q/A as stringent as this was applied to software, Microsoft - and in fact most of the software industry - would be out of business. Can you imagine a Windows recall?

    There is software out there that does not fail. Mind-bendingly complex software of the sort that "drives mere mortals mad" to boot. It is tested and retested, through all possible situations - not just the "likely 80%" of them. It is proved correct, and then verified again.

    COTS software is crap because neither the market nor the regulatory forces (such as they are, but that's a separate discussion) do not require it to be. Nor could they.

    A 747 Jumbo costs a whole lot, and while much of that cost is in the manufacture of the "big and complex thing" that it is, a significant chunk of that cost is also due to the design process, the testing, the modeling and simulation of it.

    Software is easy to scale, everyone can have a copy of the product once one is built. Cake. But spread out the cost of an error free design - tested to exhaustion, passed through V&V and so on, and you have a completely different market landscape with which to contend.

    Consumers, in the COTS context, don't mind "planned obsolescence" in their software. The current state of things proves this. People would rather have pretty features on a flaky system, than a solid system.

    --

    The REAL jabber has the user id: 13196
    What you do today will cost you a day of your life

    1. Re:Simple, yes, for other reasons by drinkypoo · · Score: 5, Funny
      Can you imagine a Windows recall?

      I must be able to, I'm feeling flushed and my nipples are hard.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  24. STFP by rice_burners_suck · · Score: 5, Insightful

    Software crashes because: Software is an immature field. Good software takes time. Software is unobvious to business managers who want the job done yesterday.

    Businessmen generally do not understand the internal workings of software. They are in a "big-picture" sort of world where software is but one pesky detail that will be taken care of. A computer crash that causes so many thousands of dollars in damages is no different than a truck crash. There is simply a risk to every element of business. If the risk is relatively low, the big shots don't care about it. Grocery stores in earthquake prone areas continue to place glass jars on the edges of shelves. Sure, there will be an earthquake one day, but it's a calculated part of business risk, and the risk is relatively low (the Earth doesn't shake every five minutes).

    Software bugs are a similar risk. It needs to look like it works. It needs to crash (and lose data) infrequently enough that the software will still sell. The business is not concerned with stamping out software bugs. It is concerned with releasing the software and making money. If the need arises, the business will improve the software and make more money. More often than not, this means adding features and shiny graphics. Fixing bugs is not very important to companies because customers do not pay for bug fixes. By the consumer, bugs are viewed as defects and their fixes should be free. By the company, bugs are viewed as a minor risk and fixing them would cost too much to justify. So you'll reboot once in a while or lose an hour's work once in a while. If it fries your hard disk, well, you should have backed up your data.

    Software is also one of the newest fields of human endeavor. Buildings have been built, ships have sailed and farms were farmed, all for thousands of years. No matter how much progress happens in these fields now, they have come so close to "perfection" that continued improvement serves to lower cost, improve safety and increase convenience. It's not a matter of, "Gee, how can we make buildings that actually stand without falling down three times a week?" It's just a matter of, "How wide, how deep, how tall and what color glass do you want on the outside?" You pay X dollars, wait Y months and voila, there is a building. But programming has been around for how long, 50 years? It's an increasingly important but very immature field.

    Buildings, bridges, ships... they're obvious. Everyone knows that if enough lifeboats aren't put on an unsinkable ship, it'll sink on purpose, just to piss you off. Everyone knows that if a 100 story building is going to stand, it has to take 10 years to build it. Everyone knows that a dam has to be pretty damn strong or it'll break and flood half the countryside. The building, shipyard and dam businesses aren't progressing at light speed. It is easy to justify 10 years for an outrageous building design because people KNOW what is involved. But software... Now that's totally unobvious. Software is an idea. It's abstract. It's a bunch of curse words that look like gobbledygook to the uninitiated. A bunch of "noise" characters on a broken terminal. Something done by a bunch of skinny, pimply faced geeks who got beat up in high school, took the ugly girl to prom and didn't have any friends. Why should a manager bother to care that fst_jejcl_reduce() causes a possible NULL pointer in the outer loop if case 32 is activated, which happens if the previous re-sort encountered two items with similar Amount fields, all of which will take a whole day to find and fix and will only happen, say, 2% of the times this particular feature is invoked by the user, which isn't that often? Why should anybody justify spending 2 years to develop some bulletproof program that can be banged out in 3 months, with bugs? What's the problem? Constructor workers are risking their lives, moving heavy things, sweating all day in the hot sun... While geeks are sitting in offices just punching crap on a keyboard. How difficult could it possibly be? To

  25. Turing showed this by martin-boundary · · Score: 4, Interesting
    A crashed computer is a computer that's stopped. Alan Turing proved in 1936 that the halting problem is unsolvable. So, it's impossible to know when and how a computer is going to crash or not under all possible circumstances (inputs).

    Accept it. It's a fact of nature.

  26. all systems crash, not just MS by dirk · · Score: 4, Interesting

    When can we finally give up the FUD of "MS crashes all the time"? Anyone who has used a later MS OS (Win2k or XP) can easily see they crash very rarely. I have had my Redhat install have more problems than my Windows install in the past 6 months, and on the MS system most of the problems have been 3rd party software while on the Linux most of the problems have been the OS itself. The reason systems crash is that there are many pieces, written by many different people, interacting with each other. This is the same whether the OS is Linux of Windows. The harping on the instability of Windows does nothing but hurt the Linux cause, since anyone who actually uses a newer version of Windows knows that the person has no basis in reality.

    --

    "Information wants to be expensive" - Stewart Brand, the same guy who said "Information wants to be free"
  27. Time is Money. by Rimbo · · Score: 5, Interesting

    I think this is basically the right answer.

    A couple of months ago, the company I worked for spent a lot of time and effort developing a robust testing methodology. We had a software product that through blood sweat and tears would not crash unless you basically blasted the hardware in some way.

    But that led to two problems. First, we only had so many people working, and resources spent testing and bugfixing were not being used to add new features. Second, the time it took to get it that robust delayed the product's release beyond the point where we could recover the investment. [Time developing] * [Cost of operating] was greater than [expected number of units sold] * [price per unit].

    What ended up happening was that we lacked the features to justify the price and number of units we needed to sell to cover the cost of developing it. We had no bugs -- and we could be certain of it -- that would crash the machine.

    As of last month, the company could no longer afford to pay me. I'm not there any more.

    The moral of the story is that trying to make a bug-free product will bankrupt your company, especially a startup. Software tools have improved, but the benefit largely goes towards adding new whiz-bang features that sell the product for more money, not to being able to fix more bugs.

    What we should do as engineers and managers of software products is to not be afraid of getting the product out the door with a few bugs in it if we want our company to do well; this business reality is ultimately why bugs will a big part of software for the forseeable future.

  28. Re:C and C++ are the problem by Anonymous Coward · · Score: 5, Insightful

    A commonly held notion, but not really well thought through.

    Sloppy programmer accesses through bad pointer in C. OS traps task.

    Sloppy programmer accesses beyond array bounds in MySafeLanguage. Runtime system traps tasks.

    In either case, your program "crashes", and the user isn't going to be any happier if you tell them that it's the "MSL virtual run time environment" that painted the blue screen of death than if it's the "operating system". The crappy program still ate my data.

    The two actual causes, IMO:

    1) People always code on the bounds of manageable complexity. Think about the programs people wrote 25 years ago. Nice as they were at the time, and they were on the bounds of manageble complexity, they have what would now be considered a laughable number of features and capabilities. As tools and processes and programmers get better, you don't get a better version of the same old thing you always had. You get something new and different that's just now become possible.

    2) Users (customers) get what they deserve. I have yet to meet a real customer that will actually wait longer and pay more for a higher quality system. Instead, they'll pay less to the guy that gets there cheaper or sooner. Everyone rants about quality, but they turn around and reward time-to-market and corner-cutting on development. If any significant proportion of users really insisted on quality, they'd get it, and probably at a much higher price. (Some, but not all, embedded development falls into this category.) Instead, they want it now and cheap, and the company that takes longer and cost more simply goes out of business.

  29. What are you smoking? by Jerk+City+Troll · · Score: 4, Interesting

    My OS X box, which I use for web browsing and word processing, crashes about once every three days.

    The Ti PowerBook G4 I am writing this post on is running Mac OS X 10.2.x. It goes in an out of sleep on an irregular basis, and not always when it is idle. I swap PCMCIA cards in and out. It hops from network to network. I do a lot more than browsing and word processing.

    According to my Konfabulator uptime widget, I have 83 days, 23 hours, 20 minutes. My load average at the moment is 1.7. It has not been rebooted since I installed OS X (I did it myself after buying it just for messing around purposes).

    You sir are either lying, have bad hardware, or you've severely corrupted your installation. This operating system (which is BSD) is solid as a rock.

  30. Re:Computers don't crash by Anonymous Coward · · Score: 5, Interesting

    The current issue of Scientific American states that 51% of crashes are due to user error. 15%=software error. 34%=hardware error. Refer to article for further info.

    You made a little "user error" there yourself-- the article says that 34%=software error and 15%=hardware error.

    Oh, and those figures are just for Web applications, not software applications in general.

    It's an interesting article. Unfortunately, they're not very clear about what constitutes a "user error." I've filled out Web forms that gave me an "error" when I included hyphens in my phone number or credit card number. That's far from an error, it's just poor user interface design.

    In my opinion, something the user does should never cause a program or operating system crash. If this can occur, it is the developer who is at fault, not the user.

    Apple's Human Interface Guidelines are a nice introduction to user-fault tolerance, even if you're developing for other platforms.

  31. Re:And by jdray · · Score: 4, Funny

    Isn't that "restore him from backup?"

    --
    The Spoon
    Updated 6/28/2011
  32. Debian. by twitter · · Score: 4, Funny

    Debian tested in every state, works good everywhere. I have yet to prove that it does not work anywhere in any way. I can not say the same thing for any other software I've ever run on a PC.

    --

    Friends don't help friends install M$ junk.

  33. Re:Computers don't crash by abirdman · · Score: 5, Insightful

    I'm afraid if a user error causes the program to crash, I've got to call it a software error. It's not that hard to write the error handling handling routines, it's just never in the budget. And the users are invariably able to discover new frontiers of errors the programmer(s) never dreamed of. No matter. If clicking the wrong box, entering the wrong data, plugging in the wrong mouse, or installing the wrong screensaver causes a program to crash it's not the users fault (bless them, for they know not), it's the programmers and design engineers fault.

    Hardware errors are another problem altogether. Luckily, it's usually quick to diagnose, and it's usually cheaper to replace hardware than software. It's great how I've been using Microsoft error reporting for about 6 months now, and it's never been their fault. They must be getting better. \snicker>

    --
    Everything I've ever learned the hard way was based on a statistically invalid sample.
  34. OT: Electric overconsumption by maynard · · Score: 5, Insightful

    I used to leave all sorts of machines running 24/7 in my apartment. Several Suns, a couple PCs running Linux and BSD, an SGI, blah blah blah. I did take care to turn monitors off though. I kept this up until I turned off all my systems (except the mail server) for a two week vacation: I was shocked to discover the next electric bill arrived a good $80 cheaper. I've since cut back to a single machine which I turn off at night. No more crazy uptimes, but honestly - I'll take the money. I wish there was consumer demand for low power destop computing. I guess I'll just have to migrate to a good laptop for the low power option. But you're absolutely right: a few computers can suck up a lot of power, with damaging results to one's electric bill. --M

    1. Re:OT: Electric overconsumption by doorbot.com · · Score: 5, Interesting
      I wish there was consumer demand for low power destop computing.

      My mail/web server would run fine off of something rediculously small, like a Sharp Zaurus. Here are my requirements, and I will pay for one if it is available.

      1. Non-x86 hardware designed for lower power -- extra speed is nice, but not required; Pentium 200 speeds or better
      2. Low power, with 9V or AA-based battery backup (changeable while system is running)
      3. 3" - 4" LCD (with manual switch to turn off) at 640 x 480, or some sort of LED array/VFD, because all I really need is a low power terminal supporting 80 x 24 characters.
      4. USB port for keyboard
      5. Serial port
      6. Two or three 10/100 NICs
      7. Full (Debian) Linux support of all hardware
      8. Some sort of expansion (PCMCIA maybe, or via USB)
      9. Support for CompactFlash for backups
      10. Hardware encryption would be a nice goodie but not required


      Yes, I could probably build this with PC104 components, but I want a pre-built product, and I'm willing to pay for it (maybe $300 - $400).
  35. it DOES cause an error by ChrisCampbell47 · · Score: 4, Interesting
    Interesting that the first two posts in the thread had English syntax errors in their first sentences. We can still understand it, but compilers/CPUs would have problems. Seems that the real problem is the difference in the natures of wetware and hardware.

    Actually, "syntax errors" like this DO cause a problem for wetware systems -- they cause the brain (well, mine at least) to kind of glaze over and take the remainder of the sentence/thought much less seriously. Kind of like aborting/returning out of a subroutine.

    Here in the Slashdot world of "definately" and "righting", I've learned that any posted comment that makes high-school-level grammatical or spelling errors is not worth my time and I immediately skip the post. I've been doing this quite rigorously lately -- blah blah blah "seperate" PAGE DOWN.

    OK now, everybody nod and think I'm talking about someone else's posts ...

    1. Re:it DOES cause an error by fucksl4shd0t · · Score: 4, Funny

      Here in the Slashdot world of "definately" and "righting", I've learned that any posted comment that makes high-school-level grammatical or spelling errors is not worth my time and I immediately skip the post. I've been doing this quite rigorously lately -- blah blah blah "seperate" PAGE DOWN.

      You are just asking for it. :) Yes, you are. So here it is:

      "high-school-level" should not be hyphenated. That is a High School level grammatical error.

      That sound you hear is the toilet flushing your shit away.

      --
      Like what I said? You might like my music
  36. Containing the Damage by Salamander · · Score: 4, Informative

    A lot of people are answering the question of why there are bugs at all, and it's an important question, but I'd like to take a different angle and consider why there are so many visible bugs. Why does a bug in a driver, or even an application, bring down a whole system? In addition to reducing the incidence of actual bugs, IMO, we should also do a better job of containing the bugs that will inevitably exist even if we all use the latest whiz-bang code analysis tools (which rarely work for kernel code anyway). Some of the semi-informed members of the audience are probably thinking that's the job of the operating system; I'd argue that our entire current notion of operating systems is flawed. There are way too many components in a typical computer system that "trust each other with their lives" in the sense that if one dies all die. Memory protection between user processes is great, but there should be memory protection between kernel entities, and other kinds of protection, as well. One of the basic services that operating systems need to provide going forward is greater fault isolation and graceful instead of catastrophic degradation.

    The Recovery Oriented Computing project at Berkeley has gotten some press recently for trying to address this issue. Many here on Slashdot don't seem to "get it" because they've never worked on systems in which a component failure was survivable; they don't realize that rebooting a single component - perhaps even preemptively - is better than having the whole system crash. "Software rot" is a real problem, no matter how hard we try to wish it away. ROC isn't about saying bugs are OK; it's about saying that bugs happen even though they're not OK, and let's do the best we can about that. Another project in the same space, with more of a hardware/security orientation, is Self Securing Devices at CMU. There, the idea is to find ways that parts of a system can work together without having to share each others' fate. While the focus of the work is on security, it shouldn't be hard to see how much of the same technology could be applied to protect a system from outright failure as well as compromise. There are plenty of other projects out there trying to address this problem, but those are two with which I happen to have personal experience.

    The key idea in all cases is that current OS design forces us to put all of our eggs in one basket, and that's really not necessary. Designing fault-resilient systems is tough - few know that better than I do - but that's only a reason why we should do it once instead of devising ad-hoc clustering solutions for each specific application. Lots of people use various forms of clustering as a way to achieve fault containment and survive failures, but the solutions tend to be very ad-hoc and application-specific. Do you think Google's solution works for anything but Google, or that a database transaction monitor is useful for anything that's not a database? Fault containment needs to be a fundamental part of the OS, not something we layer on top of it.

    --
    Slashdot - News for Herds. Stuff that Splatters.
  37. Re:Whoops, bullshit alert. by rabidcow · · Score: 4, Informative

    Microsoft says so.

    Actually it's in some driver, not the core OS, so it's not surprising that it doesn't happen to everyone. (There's a few other things with similar problems.)

  38. Re:Computers don't crash by NetCurl · · Score: 5, Insightful

    Personally I don't think not giving the user the option of defining any settings which could cause malfunction to be the answer. The reason? Well it's pretty simple, when set properly those same settings give flexibility, added functionality, and performance (at least one, sometimes two, often all three of the above).

    See, that's the thing. I like Apple's OS because at surface level, you can't get access to those features that could really break things if you screwed with them too much. If you really want to muck around with those settings, they are there and ready to be played with through various means (Terminal -- it's a freaking BSD system, Third-Party, and power-user know-how). I would like to respectfully disagree with your statment and say that by default they don't offer the option of defining settings that may cause malfunction, but in OS X they have left almost complete wiggle-room to in fact screw EVERYTHING up; if you know what you're doing. I think it's more genius than anything...
    --

    It's only when we've lost everything, that we are free to do anything...

  39. Re:Computers don't crash by TheOldFart · · Score: 4, Funny

    Eliminate the user. That takes care of half of the problems...

  40. Re:Computers don't crash by digital+photo · · Score: 5, Insightful

    I would agree. Properly and well written code will gracefully handle runtime errors.

    Translation: Short of the user fubar'ing the program or data files themselves, the program should handle all user input in a graceful way.

    The problem though is that to do this would require quite a bit of extra work.

    Progammers are caught in a situation of getting something ready for market at a time dictated to them by a department which doesn't understand the underlying issues or saying "Screw it" and making the code solid.

    That only describes one way in which the problem is caused.

    The bigger problem is the attitude people have about computers which allows for this kind of shoddy programming. People are, for the most part, okay and even expectant of their computers to crash at some point in time.

    This in turn makes it okay to release bad code which will be "fixed later".

    I say that whenever we get a crash or a problem, we report it to the company and we post it to our websites and to review sites.

    I say that the users should make it a big fat noticable problem to the companies whenever their software breaks.

    why? because it means that whenever someone who's never used the software before searches on Google for that software or software company's name, they will find page after page of complaints, dissuading them from using the software.

    the flip side is, if the software works, post to your sites and review sites. Give the people and companies who produce good software credit when it is due.

    As users and consumers, we should find ways to encourage the producers and companies to produce solid code.

    Solid stable code shouldn't be the exception to the rule.