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Ask HN: Do you still use MongoDB?

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Re: Ask HN: Do you still use MongoDB?

#61

Post by myth2018 »

Hippocrates wrote: post #42

Unfortunately. And devs are still doing triple lookups (joins) like they’re using sql, forgetting to add indices and designing/evolving schemas sloppily. Data is a mess and there’s an outage every few weeks. It’s also expensive af (probably due to improper use). It’s flexible when you’re trying to “get going” but creates pain later on. I like SQL because it is way more expressive and helps you answer questions you di…

> I like SQL because it is way more expressive and helps you answer questions you didn’t know you would have

That's precisely one of my points against using object-oriented approaches to model domain data in business-related, ERP-like applications. I always go for simpler data structures representing relational database records instead. Way more flexible.

Re: Ask HN: Do you still use MongoDB?

#62

Post by dreur »

There is a very recent Jepsen report on MongoDB. http://jepsen.io/analyses/mongodb-4.2.6

> Jepsen evaluated MongoDB version 4.2.6, and found that even at the strongest levels of read and write concern, it failed to preserve snapshot isolation. Instead, Jepsen observed read skew, cyclic information flow, duplicate writes, and internal consistency violations. Weak defaults meant that transactions could lose writes and allow dirty reads, even downgrading requested safety levels at the database and collection level.

Re: Ask HN: Do you still use MongoDB?

#63

Post by heliodor »

josephg wrote: post #27

No. Every time I've used mongodb we've ended up regretting it for one reason or another. And migrating to a different database after launch is a huge hassle. I've done a couple projects where we kicked off with postgres using JSONB columns for early iteration. Then we gradually migrated to normal SQL columns as the product matured and our design decisions crystallized. That gave us basically all the benefits of mongo…

Yep, just regret and misery.

Back in 2010 when the MongoDB hype was high, the well-known company where I was working at the time decided to build the next version of the product using MongoDB. I was on the analytics team and had to code a whole bunch of intricate map-reduce jobs to extract summary data out of Mongo. I'd repeatedly head to the product team and ask them to explain the edge cases I was seeing in the data and they would not be able to give me an answer because the data was on the third or fourth version of their mentally-stored schema and no one knew anymore. All in all, misery.

Re: Ask HN: Do you still use MongoDB?

#64

Post by scarface74 »

dreur wrote: post #62

There is a very recent Jepsen report on MongoDB. http://jepsen.io/analyses/mongodb-4.2.6 > Jepsen evaluated MongoDB version 4.2.6, and found that even at the strongest levels of read and write concern, it failed to preserve snapshot isolation. Instead, Jepsen observed read skew, cyclic information flow, duplicate writes, and internal consistency violations. Weak defaults meant that transactions could lose writes and…

Then don’t use the defaults? Sql Server use to have an empty password as a default for the Sa user and it was trivial to find servers exposed on the internet with the default password. While part of the blame was MS’s, it’s always on the person who does the installation to know what they are doing.

Re: Ask HN: Do you still use MongoDB?

#65

Post by scarface74 »

frankjr wrote: post #53

Yes. We have applications running on both PostgreSQL and MongoDB and I find that working with MongoDB is just more pleasant. I think it mostly boils down to my preference of document databases as opposed to relational ones. It feels much more natural to me to embed / nest certain properties within a document instead of spreading it across several tables and then joining everything together to get the complete data. M…

And if you’re using C#, the MongoLinq library makes using Mongo with Linq just as easy as using EF with an RDMS. We were able to easily support both in a product just by passing Linq expressions to different repository classes and the expressions were translated to either Sql or MongoQuery by the appropriate provider.

Re: Ask HN: Do you still use MongoDB?

#66

Post by scarface74 »

heipei wrote: post #39
Beefin wrote: post #33

Earlier quoted context omitted.

Atlas makes sharding easier, it's just one button where you define your partition key.

No offense, but if I wanted to have managed MongoDB I might as well use AWS DocumentDB. I honestly believe that this is a key differentiating feature for many databases. ElasticSearch, ScyllaDB, others too work the same way: Every node is equal and in order to scale you just keep adding more boxes, end of story. Compare that with what you have to do with MongoDB.

And DocumentDB is built on top of the same, proven, data storage tier as Mysql/Aurora and Postgres/Aurora.

Re: Ask HN: Do you still use MongoDB?

#67

Post by scarface74 »

doublesCs wrote: post #58
Beefin wrote: post #17

Earlier quoted context omitted.

much of the anti-mongo sentiment is around people who used it in 2009-ish. it's useful to point out that when using the early version of any software, there will be bugs. that's a trade-off early adopters always need to contend with. unfortunately, it hasn't sat well over time despite every one of the concerns being addressed since.

> much of the anti-mongo sentiment is around people who used it in 2009-ish. So? I think this is a very plausible way of measuring how much you should trust something. There had to be a downside to the "move fast and break things" that mongodb subscribes to (i.e., add features now, think about reliability later). As it turns out, they moved fast and broke their reputation.

You make technical decisions based on what happened a decade ago? Do you make all decisions based on ten year old information?

Re: Ask HN: Do you still use MongoDB?

#68

Post by tmlee »

heliodor wrote: post #63
josephg wrote: post #27

No. Every time I've used mongodb we've ended up regretting it for one reason or another. And migrating to a different database after launch is a huge hassle. I've done a couple projects where we kicked off with postgres using JSONB columns for early iteration. Then we gradually migrated to normal SQL columns as the product matured and our design decisions crystallized. That gave us basically all the benefits of mongo…

Yep, just regret and misery. Back in 2010 when the MongoDB hype was high, the well-known company where I was working at the time decided to build the next version of the product using MongoDB. I was on the analytics team and had to code a whole bunch of intricate map-reduce jobs to extract summary data out of Mongo. I'd repeatedly head to the product team and ask them to explain the edge cases I was seeing in the dat…

While there are many people here who are sharing their bad experience with MongoDB, just curious if you all find the experience with DynamoDB similar?

Since they are both of the NoSQL family.

Re: Ask HN: Do you still use MongoDB?

#69

Post by asah »

StavrosK wrote: post #49
nailer wrote: post #38

Earlier quoted context omitted.

I'm the most popular non-MongoDB-employee answer at 'to what extent are 'lost data' criticisms still valid of MongoDB?' My answer contains a history of my experiences with MongoDB that is pretty similar to yours: https://stackoverflow.com/a/18269939/123671 I feel like MongoDB now is actually a pretty stable product simply through time and investment, however I will never trust the company for using our data to beta t…

That's my attitude as well. RethinkDB, in comparison, had a much better attitude of "reliable first, fast later". Unfortunately, it turned out that when you're a database, it doesn't matter how much data you lose, only how fast you are while losing it.

The PostgreSQL community is a nice counterexample - perfectly gigantic and growing marketshare, and very very reliable.

Re: Ask HN: Do you still use MongoDB?

#70

Post by pritambaral »

scarface74 wrote: post #64
dreur wrote: post #62

There is a very recent Jepsen report on MongoDB. http://jepsen.io/analyses/mongodb-4.2.6 > Jepsen evaluated MongoDB version 4.2.6, and found that even at the strongest levels of read and write concern, it failed to preserve snapshot isolation. Instead, Jepsen observed read skew, cyclic information flow, duplicate writes, and internal consistency violations. Weak defaults meant that transactions could lose writes and…

Then don’t use the defaults? Sql Server use to have an empty password as a default for the Sa user and it was trivial to find servers exposed on the internet with the default password. While part of the blame was MS’s, it’s always on the person who does the installation to know what they are doing.

> Then don’t use the defaults?

>> ... even at the strongest levels of read and write concern, it failed to ...

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