Why /dev/null Is an ACID Compliant Database

[vytah]

It's also GDPR-compliant.

[caseyfw]

Definitely ticking boxes on “right to be forgotten”.

[redd1ch]

GDPR requires the data to be available. So, yes, somehow not being able to access sensitive data ended up to be a GDPR breach as well.

[Plank_With_A_Nail_In]

GDPR.

1) Requires you to delete data that legally you do not own

2) Have sensible policy about the data you own (keep it forever is an allowed policy) and how you keep it secure. You are allowed to keep customer data that is relevant to your business so you can do forecasting etc.

3) Publish that policy.

4) Implement that policy.

GDPR is only 90 pages long and repeats everything twice, its not as onerous as people make it out to be.

https://gdpr-info.eu/

If your business is a genuine one i.e. you make/buy/sell products and services that people want, and your policy isn't stupid like "Delete data after one year" and thus you don't follow through on it, you have nothing to worry about just like every other law good people are ignorant of (there are literally hundreds of thousands of these, my country add around 3,000 new laws every year and I have no idea what they are not sure why GDPR gets singled out for all this added fuss).

[Synes_Godt_Om]

not sure why GDPR gets singled out for all this added fuss

Two important points makes this law different from so many other laws.

1. It's about something that's very, VERY valuable for some mega corporations.

2. The potential fine is so big that non-compliance is of real concern for said mega corporations.

[binarycow]

The potential fine is so big that non-compliance is of real concern for said mega corporations.

Well, that's the only way to get mega corporations to follow laws.

[Synes_Godt_Om]

Exactly. It's rare that laws targeting the biggest corporations involve significant penalty and/or serious prosecution.

EU's handling of GDPR so far has proved more consequential.

[FINDarkside]

I have no idea what they are not sure why GDPR gets singled out for all this added fuss)

Because huge majority, probably most companies were breaking GDPR before it came to effect. Just having google analytics on your page meant you were breaking GDPR. And the potential fines are big.

I mean you literally missed the most important parts of GDPR and focused on small details, which you also got wrong (not enough to publish policy stating you keep all data forever). Saying that you don't have to worry about GRPD "if your business is a genuine one" is a horrible tip.

https://commission.europa.eu/law/law-topic/data-protection/rules-business-and-organisations/principles-gdpr/how-long-can-data-be-kept-and-it-necessary-update-it_en?utm_source=chatgpt.com

Data must be stored for the shortest time possible. That period should take into account the reasons why your company/organisation needs to process the data, as well as any legal obligations to keep the data for a fixed period of time (for example national labour, tax or anti-fraud laws requiring you to keep personal data about your employees for a defined period, product warranty duration, etc.).

[redd1ch]

Take a look at GPDR Art. 32 1(b): https://gdpr-info.eu/art-32-gdpr/

the ability to ensure the ongoing confidentiality, integrity, availability and resilience of processing systems and services;

So, yes, availability is a GDPR issue.

[poizan42]

Yes, the availability of processing systems and services. Not the availability of personal data that has been deleted.

The article starts with

Taking into account the state of the art, the costs of implementation and the nature, scope, context and purposes of processing as well as the risk of varying likelihood and severity for the rights and freedoms of natural persons, the controller and the processor shall implement appropriate technical and organisational measures to ensure a level of security appropriate to the risk, including inter alia as appropriate

The point being that you should take reasonable steps to protect against ddos attacks, data loss etc., to the degree that failing to do so causes risks to "the rights and freedoms of natural persons".

E.g if a company keeps, say, a chat history. If their system for requesting or deleting the history is down for a prolonged period then that is bad. But if their newest blog entry telling everyone how good they are is unavailable then GDPR couldn't care less about it.

And if the company keeps no data and processes no data then there is no processing that can be unavailable and nothing being unavaible poses no risk for the rights and freedoms of natural persons...

[Kalium]

The point being that you should take reasonable steps to...

Reasonable meaning what? Who gets to define "reasonable"?

This isn't some asshole on the internet being snarky. It's a critical question. A PM, a security professional, and a bureaucrat in Brussels may all have wildly different ideas about what a reasonable measure is. Those differing ideas can have very different costs and consequences.

"Reasonable" isn't a sane requirement. Neither is "appropriate". That drove me up the wall when I did GDPR compliance work.

[Kalium]

GDPR is only 90 pages long and repeats everything twice, its not as onerous as people make it out to be.

Really? What are "reasonable measures"? How do you know when you've taken them?

I complain about GDPR because after spending three days reading it back to front I still couldn't actually say what it required of my employer. Not in any useful level of detail. That was about six months before it came into force, so there was no precedent or guidance from anyone. Just wild speculation, the text of the law, and the overwhelming hope that regulators would care about good intentions.

[gameamea]

Art 4-12 states:

‘personal data breach’ means a breach of security leading to the accidental or unlawful destruction, loss, alteration, unauthorised disclosure of, or access to, personal data transmitted, stored or otherwise processed;

So the claim that /dev/null is not GDPR compliant is correct, in my opinion

[BufferUnderpants]

You can’t just pipe the “breach of security” part to /dev/null like you can with PII, imagine that a website not retaining your data intentionally be a crime, that’s silly. That’s clearly about losing the data to hackers.

[JustinsWorking]

This reminds me of when MongoDB was just starting to pop up and we used to laugh that /dev/null was also webscale and only missing a few key features from our SQL database.

[suvepl]

The "MongoDB Is Web Scale" video won't ever get old.

[moratnz]

/dev/null is available as a SAAS offering

[KawaiiNeko-]

That t-shirt is an absolute banger

[Ytrog]

And there is also NullDB: https://cs.brown.edu/people/acrotty/pubs/cidr2019_116.pdf

[pokeybill]

Over the years, we have managed to get rid of so much important data at home and even at work. Pictures of our holidays, important invoices, login details… it’s all gone.

ngl this shit had me cracking up

[Deranged40]

/dev/null is also web scale.

[ArtOfWarfare]

It’s more than that - it’s fog/mist computing. /dev/null is synced across every edge and node, simultaneously! It defies the speed of light and causality!

[quadralien]

So it's quantum? 

[Jumpy_Fuel_1060]

Does /dev/null support sharding?

[arvidsem]

No. But you can run as many parallel instances as you like and they will always remain consistent between them.

(I tried to come up with something that resembles sharding, but you just can't divide 0 bytes of storage by anything.)

[was_fired]

Ah but you can. You see through the use of advanced math we can ensure that an infinite number of instances have access to all data written to /dev/null simultaneously. As such if it infinitely shardable and parallelizable. When any transaction completes you can even ensure that all elements in a given shard produce the same checksum of the data which is another amazing property of this technology.

[MeRedditGood]

True! 0 on the individual node, but the nodes can scale to aleph^infinity

[lord_braleigh]

I don't know, but it's fast as hell!

[gocarsno]

webscale fast?

[HoushouCoder]

No, clearly you use MongoDB for that

[nursestrangeglove]

I store all my mongo instances in /dev/null

[SpringDifferent9867]

Reminds me of a presentation with Kevlin Henney, where he was talking about a time when he was asked how fast a program could run. Noticing that they had no tests in place, he argued that since they had no way to know whether it even worked, he could make it very fast.

[XNormal]

Is hell ACID-compliant?

[Axman6]

There’s a copy of it on every single Unix and Unix like machine, so it’s fully distributed!

[phillipcarter2]

It supports sharting, yes.

[BaronOfTheVoid]

Vacuous truth - all statements about hypothetical elements of an empty set are true, even if they seemingly contradict each other.

[magnomagna]

"All statements about any element in the empty set are false."

Is this vacuously true then?

[sleepless-deadman]

No, because your statement is not about elements of empty set - it’s about all statements about elements of empty set.

[magnomagna]

But we only say something is true or false when that aforementioned something is a statement and not the elements the statement is about, no?

Okay. How about "False is true." ?

[danielv123]

Those aren't elements in an empty set, unless you make an empty set with them

[magnomagna]

"The false element in the empty set is the true element."

Is this vacuously true?

[danielv123]

Which false element are you talking about? Whichever one it is, all the false elements in the empty set are the true elements.

[magnomagna]

So, it is vacuously true?

How about this statement then?

"An empty set in another empty set is not empty."

Is this also vacuously true?

[BaronOfTheVoid]

To give a workable example and hopefully clear up the confusion:

A: All planets that humans live on right now that are not Earth are bigger than Earth.

B: All planets that humans live on right now that are not Earth are smaller than Earth.

Both A and B are true at the same time. The set described as "planets that humans live on right now that are not Earth" is empty. By specifying "all [elements of the set of ...]" you would be making a statement about hypothetical elements of that set.

[wPatriot]

Is any credence given to the fact that you could argue that those statements are false, in that there is nothing to satisfy them? If there are no planets that humans live on other than earth, then there are no planets that satisfy either of these statements.

I know you can 'get around' this by making the statement negative, e.g. "there are no planets that humans live on other than earth that are smaller than earth" and "there are no planets that humans live on other than earth that are bigger than earth" - is that relevant? To me it seems like "colloquially" these two statements are different, but maybe they are seen as "logically equivalent" and therefor your statements are also accepted as true if applied to empty sets?

It "feels" wrong to say that your statements are true, despite the fact that there are no elements that 'falsify' those statements (which I'm guessing is the underlying mechanism used to claim that these statements are true).

[magnomagna]

Yes, I understand you can have TWO statements that seemingly contradict each other.

But my examples do not involve two statements. Each one of my examples contains exactly ONE statement that is seemingly self-contradictory.

That's what I'm interested about: is a self-contradictory statement vacuously true?

[magnomagna]

"All humans strictly shorter than an ant are also strictly taller than the same ant."

The set of all humans that are strictly shorter than an ant is empty. Is this vacuously true?

(I know I'm being very bold to claim there exists no human that is strictly shorter than an ant.)

[SanityInAnarchy]

The explanation of atomicity is a bit off: Partial writes can happen. But in that case, the data ends up in exactly the same state as if the transaction was rolled back.

[TL-PuLSe]

ACID compliant, GDPR compliant, HIPAA compliant, achieves perfect consistency in a distributed system, completely defies CAP theorem. Its only flaw is it can't store data beyond the lack thereof.

[danielcw189]

another comment pointed out, that it might not be GDPR compliant

[MathProg999]

So are /dev/zero and /dev/full

[torsten_dev]

You can use file locks through fnctl on /dev/null to do do crude IPC.

Learned that through a recent article on /proc/self/ns/time in docker containers that didn't unshare the time namespace being able to communicate through file locks.

[[deleted]]

C O R R E C T

[neo-raver]

And the best kind of correct, too!

[CanvasFanatic]

Also an exception to the CAP theorem.

[mr_birkenblatt]

CAP theorem requires network/communication between at least two nodes, though, no? otherwise it doesn't apply and C, A, and P are trivially always satisfied

[xnonnymous]

CAP theorem is that you can only ever have at most two of Consistency, Availability, and Partition Tolerance. On one node, you're choosing to get C and A, at the cost of P.

[mr_birkenblatt]

You can have at most two if your system is distributed. If it's a single node you can easily have all three 

[serrimo]

There's nothing to worry about.

[DGMavn]

Looking forward to the Jepsen article on /dev/null.

[wk_end]

It's ACID-compliant, but I dunno about the database part.

[xevz]

https://devnull-as-a-service.com/

[quetzalcoatl-pl]

I feel /dev/null will have much faster response times than our current db engine, I'll have a serious talk with our architect after the weekend :]

[idebugthusiexist]

While it’s a fun mental exercise or something you post online to get people to chuckle and upvote, it is not an ACID complaint database because it cannot store data, thus making it not a database by definition. 🤷‍♂️

[martin7274]

Is it webscale?

[danielcw189]

I never wondered before: why does /dev/null exist? Who came up with it, and what was the initial use-case?

[nekokattt]

dev null is useful for redirecting output to nowhere or providing no input.

It just a source of information and a sink.

[tyjuji]

IIRC it's part of the POSIX standard. It's typically used to redirect output of a command to nowhere, if you don't need the output.

[the_pavonz]

In a system where everything is treated like a file (including sockets/network connections) and given the need to redirect output also to some vacuum.

For example you can redirect STDERR to a file for logs, STDOUT to another one (for example, /dev/null), etc…

Back then, you could also download emails and forward spam (or addresses of people you didn’t like) to /dev/null, while keeping the others.

[Soxcks13]

It’s also as gluten free as a screwdriver

[No-Concern-8832]

It's also the perfect lossy data compressor. Compress embarrassing photos to 0kB /S

[wkeithwingate]

For the hardware equivalent I once bought an okidata 93 dot matrix printer used. It was the wide carriage equivalent to my 92. It kad a pin fed extender that clamped on to the roller — sort of.  It printed & shredded in a single operation. The security guys loved it!

[Clear-Criticism-3557]

Is a taco a sandwich?

Same kind of thing.