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Just another reason why mongodb is trash - does it even go without saying anymore? Every single company I've ever worked for was crushed by the unreliability o

Just another reason why mongodb is trash - does it even go without saying anymore? Every single company I've ever worked for was crushed by the unreliability of mongo. They're ultra-expensive consulting is also a ripoff - in one case the guy came, suggested a bunch of stuff w.r.t. changing up our queries and indexes, left, then a day later the database exploded and we had to roll back everything he suggested. We tried again piecemeal, which eventually lead to the same thing happening again. Eventually spending the cash to train the engineers and admins to be able to do the tuning ourselves - which ended up being completely different than the garbage the consultant suggested. Let me emphasize that this consultant was from the MongoDB company - not some third party. Completely incompetent company at all levels. Mongodb exists to extort money from idiots on their cloud offering where costs balloon out of control. It was easily 40% of our monthly infrastructure bill and what we got out of it definitely did not reflect that. We refused to pay them. Don't ever give Atlas money.

danpalmer 5y ago
I did my masters research project at university on the issues with MongoDB's distributed consensus protocol (or lack thereof). One of my friends suggested the title "Distributed Cisterns". That said, I think that the wire protocol is probably ~fine for a schemaless document store if that's what you want. I know that Apple implements MongoDB with FoundationDB, so that there are much stronger guarantees behind it, but they can still use MongoDB drivers in various languages, and that seems reasonable.
- nextaccountic 5y ago
  Can you share the pdf? Thanks.
  - rjzzleep 5y ago
    Different author but definitely worth a read: https://jepsen.io/analyses/mongodb-4.2.6 https://jepsen.io/analyses/mongodb-4.2.6 https://jepsen.io/analyses https://jepsen.io/analyses Older discussion for an older version of mongodb: https://news.ycombinator.com/item?id=9417773 https://news.ycombinator.com/item?id=9417773
BozeWolf 5y ago
We use mongodb in my current clients cloud product. I agree mongo sucks big time. It has nothing to offer for our relational data (sql please) or for our little search index (elastic, or postgres please). Except for the database, the rest of our architecture is quite alright. What i do not agree on is that their atlas product is bad. It has a very nice and helpful dashboard. Atlas is quite solid when used from google cloud (downtime/slow performance just once in 2 years) and their consultant was very helpful. Not really fast response times, but it was not urgent. Also their offering is not super expensive, but we only have 50-100gb of data. Consultancy was good value for money. Dont give atlas money because you probably want a relational database for relational data and use elastic (or postgres if small scale) for search or statistics. Mongodb also sucks with scaling, it suffers from the same issues as normal databases, except that they dont call it a problem. Which means, you, the developer should fix it. It also sucks with scaling, because expertise on using mongo is scarce. Almost done at this client. Learned a lot about mongo. Would never recommend it to another client. Would recommend running managed sql databases by a cloud provider if their offering was as good as atlas.
- altdataseller 5y ago
  Do you or anyone else have any opinions of Elastic’s Cloud offering?
mkl95 5y ago
I have worked for a couple of companies that swear by Mongo, with similar results. Mongo is just a poorly designed piece of software you shouldn't trust for any mission critical service, unless you are willing to dedicate a lot of resources to constantly put out fires.
- jart 5y ago
  Remember in the early 2010's when every bro on the Internet became an expert on scalability because he used MongoDB? https://youtu.be/b2F-DItXtZs https://youtu.be/b2F-DItXtZs (sort of like how Rust users are security experts today) I've been working on building a better database than MongoDB and it's called redbean. https://redbean.dev/ https://redbean.dev/ It supports web-scale nosql because you can use the executable pkzip structure as a document object store. It also embeds SQLite for SQL too.
- altdataseller 5y ago
  Why do they swear by it then?
  - deleted 5y ago
    [deleted]
  - HideousKojima 5y ago
    Because they don't understand RDBMSes and how to turn them for performance and have bought into cargo cult thinking.
  - mkl95 5y ago
    Sometimes tech companies have the wrong people at C-level. These people constantly make bad decisions, and have their subordinates pay for them. Investors are often oblivious to these details. If the company is not doing as well as expected due to crippling tech debt, high turnover rates, dumb decisions, etc. the CEO will come up with an excuse (since COVID, this is easier than ever).
  - rubyist5eva 5y ago
    Because they drank the kool-aid that joins are bad (so implement them in your application instead!)....oops, mongo has joins now. It's still trash.
FinalBriefing 5y ago
Is there an alternative that is easy-ish to migrate to?
deleted 5y ago
[deleted]
ithrow 5y ago
Same story with Datomic. My conclusion is that databases are hard and require lots of time and resources to be reliable.
lmilcin 5y ago
I am tech lead for for large scale trade processing system based on MongoDB for one of the largest banks in the world. We have billions of documents and tens of terabytes of data, which is all processed both daily in huge batches as well as in real time, for various reasons (regulatory, for example). MongoDB is an immature product, yes. But it is good at some things. As long as you learn what things it is good at and what things it is not good at it can be quite viable solution, depending on your problem. Learn and plan accordingly.
- rubyist5eva 5y ago
  > As long as you learn what things it is good at and what things it is not good at it can be quite viable solution, depending on your problem. My experience is that the things that mongo is "good at", there are competing products that are just as good. Mongo downsides - such as not giving a crap if you lose data - make it a non starter when there are so many better products that actually protect your data.
  - lmilcin 5y ago
    > My experience (...) So what is your experience? I have stated mine. > My experience is that the things that mongo is "good at", there are competing products that are just as good. So what does that mean? Nothing. Every product is a set of compromises. The one that is suitable doesn't need to be perfect in every (or any) respect. It just needs to have the set of compromises that suits your project. > Mongo downsides - such as not giving a crap if you lose data - make it a non starter when there are so many better products that actually protect your data. Database do not (typically) "protect" data. There are some database that make it impossible to remove data once stored, but in general if you count on your database to prevent data loss, you are just waiting for a junior engineer to make a blunder and remove half your database, whether it is MongoDB or Oracle. What all this means is that you cannot count on any database to prevent data loss and you have to organize some kind of way to protect your data. This usually means some kind of backup, snapshotted replica, redo log, etc.
    - 5y ago
Thaxll 5y ago
"Don't ever give Atlas money." Atlas works fine and it's reliable, on the consultant thing I can't comment, but MongoDB as it is today is a good DB.
ksec 5y ago
But somehow they are fifth in DB Ranking [1]. So despite all the hate on HN, they are quite widely deployed. The same goes to MySQL as well. [1] https://db-engines.com/en/ranking https://db-engines.com/en/ranking
- rubyist5eva 5y ago
  Just because something is popular doesn't make it good. Especially in web development where even the fads have fads. Managers and non-techs also eat up the sales pitch and force it on teams that don't know any better.

danpalmer 5y ago

I did my masters research project at university on the issues with MongoDB's distributed consensus protocol (or lack thereof). One of my friends suggested the title "Distributed Cisterns". That said, I think that the wire protocol is probably ~fine for a schemaless document store if that's what you want. I know that Apple implements MongoDB with FoundationDB, so that there are much stronger guarantees behind it, but they can still use MongoDB drivers in various languages, and that seems reasonable.

nextaccountic 5y ago
Can you share the pdf? Thanks.
- rjzzleep 5y ago
  Different author but definitely worth a read: https://jepsen.io/analyses/mongodb-4.2.6 https://jepsen.io/analyses/mongodb-4.2.6 https://jepsen.io/analyses https://jepsen.io/analyses Older discussion for an older version of mongodb: https://news.ycombinator.com/item?id=9417773 https://news.ycombinator.com/item?id=9417773

BozeWolf 5y ago

We use mongodb in my current clients cloud product. I agree mongo sucks big time. It has nothing to offer for our relational data (sql please) or for our little search index (elastic, or postgres please). Except for the database, the rest of our architecture is quite alright. What i do not agree on is that their atlas product is bad. It has a very nice and helpful dashboard. Atlas is quite solid when used from google cloud (downtime/slow performance just once in 2 years) and their consultant was very helpful. Not really fast response times, but it was not urgent. Also their offering is not super expensive, but we only have 50-100gb of data. Consultancy was good value for money. Dont give atlas money because you probably want a relational database for relational data and use elastic (or postgres if small scale) for search or statistics. Mongodb also sucks with scaling, it suffers from the same issues as normal databases, except that they dont call it a problem. Which means, you, the developer should fix it. It also sucks with scaling, because expertise on using mongo is scarce. Almost done at this client. Learned a lot about mongo. Would never recommend it to another client. Would recommend running managed sql databases by a cloud provider if their offering was as good as atlas.

altdataseller 5y ago
Do you or anyone else have any opinions of Elastic’s Cloud offering?

mkl95 5y ago

I have worked for a couple of companies that swear by Mongo, with similar results. Mongo is just a poorly designed piece of software you shouldn't trust for any mission critical service, unless you are willing to dedicate a lot of resources to constantly put out fires.

jart 5y ago
Remember in the early 2010's when every bro on the Internet became an expert on scalability because he used MongoDB? https://youtu.be/b2F-DItXtZs https://youtu.be/b2F-DItXtZs (sort of like how Rust users are security experts today) I've been working on building a better database than MongoDB and it's called redbean. https://redbean.dev/ https://redbean.dev/ It supports web-scale nosql because you can use the executable pkzip structure as a document object store. It also embeds SQLite for SQL too.
altdataseller 5y ago
Why do they swear by it then?
- deleted 5y ago
  [deleted]
- HideousKojima 5y ago
  Because they don't understand RDBMSes and how to turn them for performance and have bought into cargo cult thinking.
- mkl95 5y ago
  Sometimes tech companies have the wrong people at C-level. These people constantly make bad decisions, and have their subordinates pay for them. Investors are often oblivious to these details. If the company is not doing as well as expected due to crippling tech debt, high turnover rates, dumb decisions, etc. the CEO will come up with an excuse (since COVID, this is easier than ever).
- rubyist5eva 5y ago
  Because they drank the kool-aid that joins are bad (so implement them in your application instead!)....oops, mongo has joins now. It's still trash.

FinalBriefing 5y ago

Is there an alternative that is easy-ish to migrate to?

deleted 5y ago

[deleted]

ithrow 5y ago

Same story with Datomic. My conclusion is that databases are hard and require lots of time and resources to be reliable.

lmilcin 5y ago

I am tech lead for for large scale trade processing system based on MongoDB for one of the largest banks in the world. We have billions of documents and tens of terabytes of data, which is all processed both daily in huge batches as well as in real time, for various reasons (regulatory, for example). MongoDB is an immature product, yes. But it is good at some things. As long as you learn what things it is good at and what things it is not good at it can be quite viable solution, depending on your problem. Learn and plan accordingly.

rubyist5eva 5y ago
> As long as you learn what things it is good at and what things it is not good at it can be quite viable solution, depending on your problem. My experience is that the things that mongo is "good at", there are competing products that are just as good. Mongo downsides - such as not giving a crap if you lose data - make it a non starter when there are so many better products that actually protect your data.
- lmilcin 5y ago
  > My experience (...) So what is your experience? I have stated mine. > My experience is that the things that mongo is "good at", there are competing products that are just as good. So what does that mean? Nothing. Every product is a set of compromises. The one that is suitable doesn't need to be perfect in every (or any) respect. It just needs to have the set of compromises that suits your project. > Mongo downsides - such as not giving a crap if you lose data - make it a non starter when there are so many better products that actually protect your data. Database do not (typically) "protect" data. There are some database that make it impossible to remove data once stored, but in general if you count on your database to prevent data loss, you are just waiting for a junior engineer to make a blunder and remove half your database, whether it is MongoDB or Oracle. What all this means is that you cannot count on any database to prevent data loss and you have to organize some kind of way to protect your data. This usually means some kind of backup, snapshotted replica, redo log, etc.
  - 5y ago

Thaxll 5y ago

"Don't ever give Atlas money." Atlas works fine and it's reliable, on the consultant thing I can't comment, but MongoDB as it is today is a good DB.

ksec 5y ago

But somehow they are fifth in DB Ranking [1]. So despite all the hate on HN, they are quite widely deployed. The same goes to MySQL as well. [1] https://db-engines.com/en/ranking https://db-engines.com/en/ranking

rubyist5eva 5y ago
Just because something is popular doesn't make it good. Especially in web development where even the fads have fads. Managers and non-techs also eat up the sales pitch and force it on teams that don't know any better.