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Jepsen Disputes MongoDB's Data Consistency Claims

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Re: Jepsen Disputes MongoDB's Data Consistency Claims

#281

Post by kirstenbirgit »

OOPMan wrote: post #254
camgunz wrote: post #187

Earlier quoted context omitted.

It's not a type constraint. It's a hint to SQLite to try and coerce values when it can. Here's what that link parent posted says: > As far as we can tell, the SQL language specification allows the use of manifest typing. Nevertheless, most other SQL database engines are statically typed and so some people feel that the use of manifest typing is a bug in SQLite. But the authors of SQLite feel very strongly that this i…

That doesn't change the fact that it's not a good idea.

Why?

Re: Jepsen Disputes MongoDB's Data Consistency Claims

#282

Post by __Joker »

nieve wrote: post #209
ceocoder wrote: post #96

Earlier quoted context omitted.

Ah I see, we are going with “well technically it stores something therefore it is database joke”. Now I’m fully onboard :) Back when I worked in LA my CTO used to joke that most places use Microsoft Outlook as a database and Excel as BI tool.

If memory serves the original EToys.com code treated the filesystem as tree-structured database using atomic operations (though no transactions). It worked just fine, then the rewrite with an RDBMS that should have been stabler and faster resulted in the famous meltdowns. Admittedly this is cheating a bit since you can name folders & files with semi-arbitrary or internally structured string keys. By 1997 standards pu…

Interesting, is there a blog around discussing this in detail ? If not would be kind enough to go more into detail.

Re: Jepsen Disputes MongoDB's Data Consistency Claims

#283

Post by kyberias »

erulabs wrote: post #273
isatty wrote: post #208

Earlier quoted context omitted.

> You can learn a lot about a developer by asking "What do you think about Mongo, JavaScript, or PHP", and if their response isn't a shrug, they're probably more concerned with what editor is correct than if the product they're building is useful. It's an exceptional filter to reject zealots and find pragmatists. Sure, if they’re being rude about it. A developer saying that it will not fit the use case or talking abo…

Yes, I couldn't agree more. Didn't mean people can't have opinions of course - just that they shouldn't be scoffing/laughing at tools - to me its a particularly red flag. Not wanting to use a particular tool is totally fine!

> just that they shouldn't be scoffing/laughing at tools

Why on earth would that be a problem? Why are you sensitive about tools? Do the tools have feelings?

Re: Jepsen Disputes MongoDB's Data Consistency Claims

#284

Post by codecamper »

This corruption is brought on by the stock market.

Have a look also at Shopify. They go and tack on 2% fees when customers use Google Pay or Apple Pay to checkout with. They recently announced that FB would be pulling ecom sales within app, and yet Shopify plans to charge 2% on top of FB fees. That's what I could gather despite the pricing being rather opaque.

Is this a step forward or backwards? Charging 2% / transaction for modern Internet protocols running on cheap hardware across a public network?

Re: Jepsen Disputes MongoDB's Data Consistency Claims

#285

Post by tincholio »

OOPMan wrote: post #246
madhadron wrote: post #27

In the circles I run in, MongoDB is regarded as a joke and the company behind it as basically duplicitous. For example, they still list Facebook as their first user of MongoDB on their website, for example, but there is no MongoDB use in Facebook hasn't been for years (it came in only via a startup acquisition). I had the misfortune to use MongoDB at a previous job. The replication protocol wasn't atomic. You would f…

As a skateboarder I've always found the name itself rather amusing as the term mongo has relatively negative connotations in skating.

It also does in Spanish, it's a (rather old, but still used) shortened version of "retard" (from "mongólico", originally used to describe people with Down's syndrome).

Re: Jepsen Disputes MongoDB's Data Consistency Claims

#286

Post by akamaozu »

nieve wrote: post #209
ceocoder wrote: post #96

Earlier quoted context omitted.

Ah I see, we are going with “well technically it stores something therefore it is database joke”. Now I’m fully onboard :) Back when I worked in LA my CTO used to joke that most places use Microsoft Outlook as a database and Excel as BI tool.

If memory serves the original EToys.com code treated the filesystem as tree-structured database using atomic operations (though no transactions). It worked just fine, then the rewrite with an RDBMS that should have been stabler and faster resulted in the famous meltdowns. Admittedly this is cheating a bit since you can name folders & files with semi-arbitrary or internally structured string keys. By 1997 standards pu…

I was thinking of doing something similar as a lightweight embedded datastore: apply structure to the file system like you would a redis key.

Would love to talk to anyone on the EToys team or anyone who has done something similar.

I'm @akamaozu on twitter.

Re: Jepsen Disputes MongoDB's Data Consistency Claims

#289

Post by nieve »

akamaozu wrote: post #286
nieve wrote: post #209

Earlier quoted context omitted.

If memory serves the original EToys.com code treated the filesystem as tree-structured database using atomic operations (though no transactions). It worked just fine, then the rewrite with an RDBMS that should have been stabler and faster resulted in the famous meltdowns. Admittedly this is cheating a bit since you can name folders & files with semi-arbitrary or internally structured string keys. By 1997 standards pu…

I was thinking of doing something similar as a lightweight embedded datastore: apply structure to the file system like you would a redis key. Would love to talk to anyone on the EToys team or anyone who has done something similar. I'm @akamaozu on twitter.

Unfortunately eToys imploded a couple of years later (2001) and there were only a few people involved at that stage so it's possible none of them are in the industry anymore. You might start by looking at email servers, I believe there are a few that use a deeply nested directory heirarchy for much the same reasons. IIRC Apple also does something similar with the interior of the sparsebundles used in Time Machine backups, but I don't know if any of that code is opensource.

Re: Jepsen Disputes MongoDB's Data Consistency Claims

#290

Post by thaumasiotes »

jen20 wrote: post #177
kyllo wrote: post #128

Earlier quoted context omitted.

I was floored by this comment yesterday from one of their Developer Relations people: > Did any of you actually read the article? We are passing the Jepsen test suite and it was back in 2017 already. So, no, MongoDB is not losing anything if you know what you are doing. https://twitter.com/MBeugnet/status/1253622755049734150?s=20 Can you imagine saying the phrase "if you know what you are doing," in public, to your u…

Firstly let me point out that this response is neither intended as a defence of MongoDB defaults which are atrocious, or of the company, who are arguably duplicitous. However I can _quite easily_ see how a non-native English speaker could use the phrase “if you know what you are doing” to mean “if you are careful”.

> I can _quite easily_ see how a non-native English speaker could use the phrase “if you know what you are doing” to mean “if you are careful”.

This kind of thing is a scourge. I had a Chinese friend respond to something I said once by saying "that's nice". It looks so innocent... but it's really hard to overlook the fact that "that's nice" is a serious insult coming from a native speaker. I had to ask them to please never use that phrase to me again.

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