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0 pointsAtlasBarfed2y ago0 comments

Last I heard of MongoDB it was getting utterly buried by the Jepsen guy, and for anyone that follows distributed systems at some technical level, that is damning. He finds stuff wrong with everything, but that one was particularly damning.

MongoDB has always seemed to place write consistency secondary to other priorities (mostly sales / read / features) which is frankly a crap way to do a database, much less a distributed one. And I am so sick of MongoDB basically saying "no it's fixed in the new version" which is always a major red flag.

Right now it's getting its lunch eaten by Postgres's document interface from what I can tell.

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threeseed2y ago

a) Every distributed database has had serious issues with Jepsen.

b) MongoDB has been growing revenue ~40% year on year for the last few years.

c) PostgreSQL is only a serious competitor for MongoDB if you have small datasets. After all these years PostgresSQL still is ridiculously poor when it comes to clustering, replication etc. Everyone's solution of "just buy a bigger instance" is just laughable.

KptMarchewa2y ago

Growing revenue of a owner company as a argument for database? We have an Oracle fan here.

AtlasBarfedOP2y ago

Jepsen does find stuff with everything. Thus you have to know what is being discussed is serious and blatantly bad, or just the usual "wow distributed is hard".

Which is why his papers are so great.

But the MongoDB one was "wow this is bad".

threeseed2y ago

Every distributed database has been "wow this is bad".

I assume you have an example of one that wasn't ?

AtlasBarfedOP2y ago

"MongoDB’s default level of write concern was (and remains) acknowledgement by a single node, which means MongoDB may lose data by default."

Cassandra doesn't do that, consistency level is fundamental to the documentation and user guide. That is AWFUL.

"Curiously, MongoDB omitted any mention of these findings in their MongoDB and Jepsen page. Instead, that page discusses only passing results, makes no mention of read or write concern, buries the actual report in a footnote, and goes on to claim:

    MongoDB offers among the strongest data consistency, correctness, and safety guarantees of any database available today.

That is fraud. That is clownshow. Enjoy your increasing revenue.

1 more reply

doctor_eval2y ago

Although it was some time ago and I may be misremembering, I seem to recall reading the Jepsen article on RedPanda and thinking that it (and Postgresql) were among the better reports.

Certainly, not all Jepsen reports are all that bad, and tbh I'm at leaast as interested in the way the vendors respond (some of which have been terrible).

j / k navigate · click thread line to collapse

0 comments

threeseed2y ago

a) Every distributed database has had serious issues with Jepsen.

b) MongoDB has been growing revenue ~40% year on year for the last few years.

KptMarchewa2y ago

Growing revenue of a owner company as a argument for database? We have an Oracle fan here.

AtlasBarfedOP2y ago

Jepsen does find stuff with everything. Thus you have to know what is being discussed is serious and blatantly bad, or just the usual "wow distributed is hard".

Which is why his papers are so great.

But the MongoDB one was "wow this is bad".

threeseed2y ago

Every distributed database has been "wow this is bad".

I assume you have an example of one that wasn't ?

AtlasBarfedOP2y ago

"MongoDB’s default level of write concern was (and remains) acknowledgement by a single node, which means MongoDB may lose data by default."

Cassandra doesn't do that, consistency level is fundamental to the documentation and user guide. That is AWFUL.

    MongoDB offers among the strongest data consistency, correctness, and safety guarantees of any database available today.

That is fraud. That is clownshow. Enjoy your increasing revenue.

1 more reply

doctor_eval2y ago

Although it was some time ago and I may be misremembering, I seem to recall reading the Jepsen article on RedPanda and thinking that it (and Postgresql) were among the better reports.

Certainly, not all Jepsen reports are all that bad, and tbh I'm at leaast as interested in the way the vendors respond (some of which have been terrible).

j / k navigate · click thread line to collapse