Microkernel?

By: Andrey (andrey.semashev.delete@this.gmail.com), March 21, 2021 9:34 am
Room: Moderated Discussions
iz (iz.delete@this.nothing.com) on March 21, 2021 2:58 am wrote:
> Andrey (andrey.semashev.delete@this.gmail.com) on March 16, 2021 10:06 am wrote:
> > It's not just about restoring previous state and continuing from there. Most workloads involve
> > repetitive activities, like processing many more-or-less similar user requests or processing
> > similar data bundles or whatever. If a piece of software crashed on one iteration then it
> > is very likely going to crash after restart on the next similar activity.
>
> Only if it is exactly the same in a specific way, either in
> unexpected content, or in unexpected timing (or both).
>
> But even if it may crash next time, you want to at least try it again, right? Or would
> you rather have everything stop because one user request tripped it over? And surely
> you agree that restarting the software should be possible to begin with?

Yes, restarts usually do have a positive overall effect. My point was that that effect will be most often not satisfactory enough. I mean, depending on your active user base and the nature of your service, failing even a small percentage of user requests can be devastating.

> > There are, of course, cases when the software crashes every once in a while, when Moon
> > is in the right position. Restarts do help to keep the system mostly running when these
> > happen. However, such cases are more rare than the other, more "stable" kind of bugs.
>
> Not in my experience. I guess it depends on how well your software is tested before deployment.

In the modern conventional software (and even not so conventional, such as OS kernels and firmwares), the "release often, release early" approach won, for better or worse. Developers tend to rely on automated testing tools and unit tests these days, while manual and integrated testing becomes less and less common. This means your users will likely be your guinea pigs.

> So let's rephrase to: Yes, those easy bugs are more common before deployment, but the rare bugs are more common
> after deployment. The opposite is only true if your customers test your software better than you do.

Exactly, on the latter sentence.

You are lucky if you can cover all the common use cases in your internal testing, but that is often either too expensive or impractical, especially if it requires special hardware setups and third party licenses. There is software that is supposed to be compatible with third party components (addons/plugins/whatever), so you can't possibly test it with every one of them. Of course, there are lots of other specifics, and more complete testing is easier for some software than the other. But if you are unlucky (or unmotivated, or poor, or time constrained, or just lazy) then you can only hope you did good while designing and coding your software and it will not fail. And sometimes that hope does not hold true, and you get those "stable" crashes in production.

The irony is that all those heisenbugs tend to be caught quite well early by various sanitizers, valgrind and whatnot during the automated testing, while the design bugs that only manifest themselves in certain conditions tend to crop up much later, when the software is used in the field. A user will always find a way to surprise the developer.
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TopicPosted ByDate
x86 - why unite when you can fragment?anonymou52021/03/12 06:16 PM
  x86 - why unite when you can fragment?Linus Torvalds2021/03/13 01:18 PM
    x86 - why unite when you can fragment?Jon Masters2021/03/13 07:25 PM
      x86 - why unite when you can fragment?Jon Masters2021/03/13 07:44 PM
        x86 - why unite when you can fragment?Yuhong Bao2021/03/13 08:49 PM
        x86 - why unite when you can fragment?tt2021/03/20 09:30 AM
    x86 - why unite when you can fragment?Andrey2021/03/14 04:15 PM
      x86 - why unite when you can fragment?Linus Torvalds2021/03/14 04:58 PM
        x86 - why unite when you can fragment?anonymou52021/03/14 05:31 PM
          x86 - why unite when you can fragment?anon22021/03/14 08:07 PM
        Microkernel?Anon2021/03/14 11:49 PM
          Microkernel?none2021/03/15 12:37 AM
            Microkernel?Anon2021/03/15 01:56 AM
          Microkernel?anon22021/03/15 01:58 AM
            Microkernel?Simon Farnsworth2021/03/15 03:12 AM
              Microkernel?anon22021/03/15 04:53 AM
                Microkernel?Simon Farnsworth2021/03/15 06:56 AM
                  Microkernel?iz2021/03/15 08:10 AM
                    Microkernel?Anon2021/03/15 09:05 AM
                      Microkernel?iz2021/03/16 01:25 AM
                        Microkernel?Andrey2021/03/16 02:54 AM
                          Microkernel?iz2021/03/16 08:36 AM
                            Microkernel?Andrey2021/03/16 10:06 AM
                              Microkernel?anonymou52021/03/16 11:44 AM
                              Microkernel?iz2021/03/21 02:58 AM
                                Microkernel?Andrey2021/03/21 09:34 AM
                  Microkernel?anon22021/03/15 08:31 AM
                    Microkernel?Simon Farnsworth2021/03/16 04:42 AM
            Microkernel?Gabriele Svelto2021/03/15 03:21 AM
              Microkernel?anon22021/03/15 04:56 AM
                Microkernel?Gabriele Svelto2021/03/15 10:41 AM
                  Microkernel?anon22021/03/15 08:00 PM
                    Microkernel?Gabriele Svelto2021/03/16 07:23 AM
                      Microkernel?anon22021/03/16 05:13 PM
                        Microkernel?anon22021/03/16 05:16 PM
                    Microkernel?Gian-Carlo Pascutto2021/03/16 01:40 PM
                      Microkernel?anon22021/03/16 05:53 PM
                        Microkernel?Linus Torvalds2021/03/16 07:25 PM
                          Microkernel?Doug S2021/03/17 09:30 AM
                            Microkernel?Linus Torvalds2021/03/17 10:30 AM
                              Microkernel?Brendan2021/03/17 10:56 PM
                                Microkernel?Michael S2021/03/18 03:47 AM
                                  Microkernel?Brendan2021/03/18 09:07 AM
                              Microkernel?Jose2021/03/18 09:35 AM
                            Microkernel?zArchJon2021/03/18 05:42 PM
                          TransputerRichardC2021/03/17 09:47 AM
                          Microkernel?dmcq2021/03/17 11:15 AM
                            Microkernel?Linus Torvalds2021/03/17 11:59 AM
                              Microkernel?dmcq2021/03/17 12:38 PM
                              Microkernel?Adrian2021/03/17 01:00 PM
                              Microkernel?Ana R. Riano2021/03/18 04:33 AM
                              Microkernel?2021/04/30 04:52 PM
                          Microkernel?NvaxPlus2021/03/17 11:48 AM
                            Microkernel?Michael S2021/03/18 03:32 AM
                              Microkernel?Adrian2021/03/18 04:12 AM
                                Microkernel?dmcq2021/03/18 06:30 AM
                                  Microkernel?dmcq2021/03/18 06:55 AM
                                  Microkernel?Adrian2021/03/18 08:35 AM
                                    Microkernel?---2021/03/18 09:49 AM
                                    Microkernel?dmcq2021/03/18 10:59 AM
                                      Microkernel?dmcq2021/03/18 04:09 PM
                              Microkernel?---2021/03/18 09:27 AM
                          Microkernel?Kalle A. Sandström2021/03/20 06:34 AM
                            Microkernel?---2021/03/20 08:35 AM
                            Microkernel?anon22021/03/21 05:29 PM
            Microkernel?dmcq2021/03/15 04:06 AM
              Microkernel?anon22021/03/15 04:59 AM
                Microkernel?dmcq2021/03/15 11:51 AM
                  Microkernel?anon22021/03/15 08:31 PM
                    Microkernel?dmcq2021/03/16 09:17 AM
                      Microkernel?Jukka Larja2021/03/16 11:22 AM
                        Microkernel?dmcq2021/03/16 04:06 PM
                          Microkernel?Jukka Larja2021/03/17 03:42 AM
                            Microkernel?dmcq2021/03/17 07:00 AM
                      Microkernel?anon22021/03/16 05:26 PM
                    Microkernel?---2021/03/16 10:07 AM
            Microkernel?-.-2021/03/15 08:15 PM
              Microkernel?anon22021/03/15 09:18 PM
                Microkernel?Foo_2021/03/16 03:37 AM
                  Read the thread (NT)anon22021/03/16 05:27 PM
                    Already did (NT)Foo_2021/03/17 02:55 AM
                      Already didanon22021/03/17 03:46 AM
                        Already didEtienne Lorrain2021/03/18 02:31 AM
                Microkernel?-.-2021/03/17 05:04 AM
                  Microkernel?Gabriele Svelto2021/03/17 08:53 AM
                    Microkernel?-.-2021/03/17 02:43 PM
              Microkernel?dmcq2021/03/16 08:40 AM
        x86 - why unite when you can fragment?Konrad Schwarz2021/03/17 10:19 AM
    x86 - why unite when you can fragment?anonon2021/03/15 07:37 AM
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