/dev/null is an ACID compliant database

(jyu.dev)

365 points | by swills 12 hours ago ago

116 comments

  • jihadjihad 8 hours ago

    In a similar vein, this is one of the most interesting things I’ve come across on HN over the years:

    https://www.linusakesson.net/programming/pipelogic/index.php

    Past HN post: https://news.ycombinator.com/item?id=15363029

    • jmux 4 hours ago

      I hadn’t seen this before, this is sick! thanks for posting it here :)

  • gchamonlive 10 hours ago

    Best stack cloud providers don't want you to know about, /dev/null for db and https://github.com/kelseyhightower/nocode for the backend.

    • nomel 9 hours ago

      I've never had a single issue with any user after moving our databases to /dev/null.

    • quietbritishjim 10 hours ago

      WTF is going on with the issues and pull requests for that repo?

      • sundarurfriend 9 hours ago

        The less substance there is to it, the easier it is to talk about.

        The Chinese comments ("issues") also seem to be the same kind of jokes as the English ones, "no code means no bugs, perfect", etc., from the few I tried getting translations of. I imagine this went viral on Chinese social media, which makes sense since it's the sort of joke that's easy to translate and doesn't depend on particular cultural assumptions or anything.

      • thelastgallon 7 hours ago

        Looks like the code for MCP support is reviewed and merged: https://github.com/kelseyhightower/nocode/pull/5540

      • gchamonlive 10 hours ago

        In nocode you fix nothing and you don't change anything, that's why issues and pull requests are a mess, they literally cannot be dealt with by design.

      • gchamonlive 7 hours ago

        This commit is interesting, it used to support /dev/null natively, but for the sake of supporting windows you now have to use /dev/null externally by writing nothing at all

        https://github.com/kelseyhightower/nocode/commit/80f38e0f103...

      • fennec-posix 10 hours ago

        Had to see for myself, and yeah... that's a whole lot of chaos. I'm sure I'd get the joke if I could read Chinese though.

        • eru 7 hours ago

          Ask Google Translate?

      • SanjayMehta 10 hours ago

        They're using it to communicate in code to each other.

        • QuantumNomad_ 9 hours ago

          Well they should stop that and start communicating in nocode instead.

    • bravetraveler 4 hours ago

      1.0.1 update: more nothing

  • pyuser583 11 hours ago

    I've used /dev/null for exactly this purpose. I have output that needs to go somewhere, and I don't want to worry about whether that somewhere can handle it.

    Later on in deployment, it will go somewhere else. Somewhere that has been evaluated for being able to handle it.

    In that way, /dev/null is to storage what `true` is to execution - it just works.

    • CaptainOfCoit 11 hours ago

      Bug free software is a pipe dream, but if there is anything I've never encountered any bugs with, /dev/null and true is certainly in the top 3.

      • noir_lord 10 hours ago

        Joking aside I can’t ever remember seeing a bug in either bash or zsh, never seen either crash or segfault and anytime I’ve had weirdness it’s always turned out to be me missing something.

        Both (along with a lot of the standard utilities) are a testament to what talented C programmers plus years of people beating on them in unintended ways can achieve in terms of reliability/stability.

        • 1718627440 9 hours ago

          Programs not outputting a final newline to stdout leave a prompt that doesn't start on column 0, and readline seams to not takes this into consideration, but still optimizes redraws and overwrites so you get an inconsistent display. This bugs seam to exist in a lot of shells and interactive programs. The program causing the issue isn't POSIX conform though.

          • latexr 8 hours ago

            > seams

            The correct spelling is “seems”. I first assumed it was a typo, but since you did it twice I thought you might like to know.

        • rkeene2 8 hours ago

          I had a fun bug where bash would run scripts out of order!

          This would lead to impossible states, like

          if cat foo | false; then echo hmm; fi

          Producing output sometimes, depending on whether or not `cat foo` or `false` return value was used

          [0] https://lists.gnu.org/archive/html/bug-bash/2015-06/msg00010...

          • lhmiles 3 hours ago

            This was an interesting read.

        • gucci-on-fleek 10 hours ago

          > I can’t ever remember seeing a bug in either bash

          Shellshock [0] is a rather famous example, but bugs like that are rare enough that they make the news when they're found.

          [0] https://en.wikipedia.org/wiki/Shellshock_%28software_bug%29

        • AdieuToLogic 7 hours ago

          > Joking aside I can’t ever remember seeing a bug in either bash or zsh, never seen either crash or segfault and anytime I’ve had weirdness it’s always turned out to be me missing something.

          Given that this statement begins with "joking aside", I have to assume it is either a meta-joke or an uninformed opinion. Taking the subsequent sentence into account thoroughly reinforces the former.

          Well played. :-)

        • PokestarFan 9 hours ago

          I've been able to trigger a segfault in zsh with certain plugins, a directory with a lot of files/folders, and globs with a bunch of * characters.

        • qwertox 10 hours ago

          Amen.

      • MartijnBraam 6 hours ago

        Ah you've never encountered /dev/null not existing yet, so when you try to trash data it will actually create a normal file there so every other program that uses it will actually append that file.

        Luckily it's usually a tmpfs

      • SanjayMehta 9 hours ago

        False.

        Wait: that's just not true.

        Carry on.

  • cluckindan 11 hours ago

    Always instantly consistent, always available, and perfectly tolerant of partitioning.

    Truly, it is the only database which can be scaled to unlimited nodes and remain fully CAP.

    • inopinatus 9 hours ago

      Enterprise DBAs will nevertheless provision separate /dev/null0 and /dev/null1 devices due to corporate policy. In the event of an outage, the symlink from null will be updated manually following an approved run book. Please note that this runbook must be revalidated annually as part of the sarbox audit, without which the null device is no longer authorised for production use and must be deleted

    • eru 7 hours ago

      Not just instantly consistent on one machine, but globally sharded all across the universe.

    • thfuran 11 hours ago

      It's really fast too.

    • tgma 11 hours ago

      Always available? Clearly you have not experienced situations with no /dev mounted.

      • pasteldream 10 hours ago

        One easy way to create such a situation is to use bwrap without --dev.

    • ozim 11 hours ago

      I guess we have a perfect idea for vaporware here. (pun intended)

      I am putting my marketing hat on right now.

    • geoffbp 7 hours ago

      Is there a case where dev null can fail?

      • tgv 3 hours ago

        I can think of two: whe running out of file descriptors or memory. But then /dev/null1 would fail too.

  • mjb 8 hours ago

    Best of all, /dev/null is also serializable (but not strict serializable) under many academic and textbook definitions.

    Specifically, these definitions require that transactions appear to execute in some serial order, and place no constraints on that serial order. So the database can issue all reads at time zero, returning empty results, and all writes at the time they happen (because who the hell cares?).

    The lesson? Demand real-time guarantees.

    • mjb 8 hours ago

      This doesn't work as cleanly for SQL-style transactions where there are tons of RW transactions, sadly.

  • jefftk 9 hours ago

    "The system transitions from one valid state to another" is clearly false: the system only has a single state.

    • mpyne 7 hours ago

      One of the first state machine you'll ever learn about in undergrad permits transitions from a state back to itself, so I don't see this as a barrier.

      • eru 7 hours ago

        And you can implement /dev/null with multiple states, as long as you make them all behave the same way.

  • rezonant 11 hours ago

    But is /dev/null web scale?

    • epistasis 11 hours ago

      Yes, /dev/null can even power sites like zombo.com

      • bottled_poe 11 hours ago

        What’s the I/O throughput of /dev/null ?

        • epistasis 11 hours ago

          Single client, I'm getting ~5GB/s, both on an 8-year-old intel server, and on my M1 ARM chip.

          However with a single server, it doesn't perfectly linearly scale with multiple clients. I'm getting

          1 client: 5GB/s

          2 clients: 8GB/s

          3 client: 8.7GB/s

          • dinkelberg 10 hours ago

            How did you measure this? Do you know that /dev/null is the limiting factor, or could it be the data source that is limiting?

          • fukka42 10 hours ago

            I'm easily reaching 30GB/s with a single client:

                dd if=/dev/zero of=/dev/null bs=1M status=progress
            
            A second dd process hits the same speed.
            • epistasis 10 hours ago

              My artisanal architecture design uses writes with a few characters and uses unix pipes:

                  yes | pv > /dev/null
              
              I hope that in my next rewrite I can advance to larger block sizes.
            • rezonant 10 hours ago

              What's the best hardware for running a /dev/null instance for production?

              • __turbobrew__ 9 hours ago

                A single resistor at ground voltage.

                • eru 7 hours ago

                  That doesn't support expected features like 'stat /dev/null'.

              • epistasis 9 hours ago

                I usually do a kubernetes cluster on top of VMs. But sometimes when I really want to scale the standard cloud server less platforms all support /dev/null out of the box. (Except for Windows...)

                • wowczarek 8 hours ago

                  > Except for Windows...

                  copy c:\file nul

                  It's been there since DOS or more likely CP/M :)

                  • epistasis 6 hours ago

                    Still need an adapter library though! Fortunately there are about 7 competing implementations on npm and most of them only have 5-6 transitive dependencies.

        • CaptainOfCoit 11 hours ago

          You start dealing with Heisen-throughput at that point, it goes as high as you can measure.

    • pasteldream 11 hours ago

      reference for the unaware: https://youtube.com/watch?v=b2F-DItXtZs

    • butteredpecan 10 hours ago
  • tech234a 9 hours ago

    This reminds me of the S4 storage service: http://www.supersimplestorageservice.com/

    Discussed on HN a few times, but apparently not for a few years now: https://hn.algolia.com/?q=http%3A%2F%2Fwww.supersimplestorag...

  • sph an hour ago

    It's ACID compliant. But it's not a database.

    • ozim 41 minutes ago

      W just need R&D money to solve reading back from it, but that's just a matter of time we can definitely solve it in a year or two.

      This tech is just around the corner I promise, then we will be first to the market and all the big tech companies will want to buy us out, imagine how much we can earn.

      /s

      • sph 11 minutes ago

        If you have infinite time, you can find your data in /dev/random

  • yard2010 3 hours ago

    I love vacously truths (not sure if this is how you say it in English)

    All the people I've met in London were androids.

    • tczMUFlmoNk 3 hours ago

      The term is correct. Grammatically, we would say, "I love vacuous truths", or, "I love vacuously true statements". (To my ear the second version sounds very slightly more appropriate, because in mathematics "vacuously true" is a bit of a set phrase, but both are fine.)

  • simultsop 5 hours ago

    You need an FAQ section, we have so many questions for this marvellous solution.

    Is it portable to all linux distros?

    Where is the ubuntu command to install it?

    What license does it use, is it free or else?

    Is it really open source or source only?

  • theandrewbailey 8 hours ago

    /dev/null is the ultimate storageless function. It's like serverless, but for PII, and deployable anywhere!

  • raggi 3 hours ago
  • imcritic 11 hours ago

    How does a disaster recovery plan with it look like?

    • tadfisher 11 hours ago

      There is never a disaster; reading from /dev/null will return the same result before and after any external event.

    • wolrah 10 hours ago

      /dev/null is globally redundant across almost every *nix-ish system in operation. Just reinstall your software on whatever is convenient and all the same data will be there.

    • mpyne 7 hours ago

          sudo mknod /dev/null c 1 3 && sudo chmod 666 /dev/null
      
      might do it on many systems
  • novoreorx 4 hours ago

    What a weird title, you can say it's ACID but it's not a database

    • sevg 4 hours ago

      > What a weird title, you can say it's ACID but it's not a database

      You’re right, we should ban jokes that aren’t 100% correct!

      • novoreorx an hour ago

        Sorry if you feel my words mean. I'm not criticizing the joke, I just think it could make a better title, even for a joke, by adding quotes around "database" or calling it a "storage service," since it does allow data to be read. A good joke is both entertaining and difficult to deny.

  • hmokiguess 10 hours ago

    I guess it is also idempotent then

  • 1970-01-01 9 hours ago

    So if you could somehow get something stuck in /dev/null would it cause a panic or what happens?

  • yuppiemephisto 7 hours ago

    And the axiom of empty set is an inaccessible cardinal axiom

  • hshdhdhehd 7 hours ago

    It is also local first, low latency, data residency compliant, SOC2 compliant, zero dependency and webscale.

  • keithnz 9 hours ago

    took a while to pipe my multi-terabyte db to /dev/null but now that I have I'm saving a ton of money on storage.

  • Perz1val an hour ago

    Don't forget to feed your void. `dd if=/dev/zero of=/dev/null bs=500M count=1`

  • ramon156 an hour ago

    I'm gonna be that guy, tyop at the bottom

    > entreprise

  • johnfn 9 hours ago

    Not only that, it provides all 3 components of CAP!

    • _joel 8 hours ago

      The Jespsen tests pass quickly too!

  • BiraIgnacio 8 hours ago

    A strong business opportunity right there.

  • layer8 9 hours ago

    Not on Windows.

  • DeathArrow 4 hours ago

    More than that, /dev/null is infinitely scalable.

  • bitwize 9 hours ago

    Yes, but does it support sharding? Sharding is the secret ingredient in the web scale sauce.

  • idontwantthis 9 hours ago

    This reminds me of how I would write a HashCode implementation on intro CS exams in college:

    ‘return 5’

  • justinhj 6 hours ago

    Add an mcp server and I'm in

  • dheera 7 hours ago

    I guess /dev/null is also an excellent source of investment advice, you are guaranteed to not lose money

  • doublerabbit 10 hours ago

    Idea: NaaS. Null as a service.

  • tonyhart7 5 hours ago

    it looks promising but what about AI /dev/null usage????

  • blourvim 7 hours ago

    I love this

  • charcircuit 10 hours ago

    /dev/null is not a database. By this logic is a hard disk a database, is a CD a database. No. They are storage mediums. You could store a database on them, but they themselves are not a database.

    Considering there is no way to read back data written to /dev/null it will not be useful for storing database data.

    • jonathrg 9 hours ago

      You can store any data as long as it doesn't contain any ones

      • saltcured 7 hours ago

        And, you don't depend on it remembering how many zeros you wrote last.

    • chrisweekly 9 hours ago

      seems you've missed the joke

      • charcircuit 9 hours ago

        It's not a funny one if it was one. Of course something is going to be a bad database if it's not a database.

        • brobbin 8 hours ago

          It's nerd humor. You're not supposed to find it funny, but nod along approvingly while noticing how awfully clever you are for noticing the attempt at being funny.

        • voidfunc 8 hours ago

          "Its not funny" says the one guy in a room where literally everyone else is laughing and riffing on the joke.

          Your humor unit might be defective.

        • jfengel 8 hours ago

          It's not a great joke, to be sure. But the essence of it is that it's a good database, by relevant but inappropriate standards.

          • tgv 3 hours ago

            Insufficient/incomplete rather than inappropriate, perhaps?

  • QuiCasseRien 11 hours ago

    Fast and easy to read, funny and fuckingly true !

    best post of the week ^^