

Why The MongoDB Hate? - mangolicious
http://yourstartupsucks.com/post/12416816599/why-the-mongodb-hate
A wise opinion on "MongoGate" haters.
======
timr
_"MongoDB is designed to be run on a machine with sufficient primary memory to
hold the working set. In this case, writes finish extremely quickly and
therefore lock contention is quite low. Optimizing for this data pattern is a
fundamental design decision."_

Yeah, well, that's a problem. MySQL and Postgres perform dramatically better
if you keep everything in memory, too -- but they _don't fall over if they
have to hit the disk_. (And yes, they can handle lots of concurrent writes,
even when the working set is larger than RAM.)

I have no particular bias for or against MongoDB, but arguing that it's peachy
because its biggest limitations were designed-in from the start isn't a
winner. Some of us want tools that aren't going to fail under reasonably
expected application loads. Also, arguing that Enthusiastic Developers are
Working Really Hard on fixing those limitations isn't especially compelling
(I'm still waiting for Enlightenment 17...)

~~~
rdtsc
Sometime the best marketing for your product is stupid marketing of
competitor's product. Those that worry about their data when they read what
supporters are saying and they hear "writes finish extremely quickly and
therefore lock contention is quite low" because "it is all in memory" will
turn around and walk away.

Some who are nice will take the time to explain and criticize that is such a
bad design (and those will be deemed as haters), most will just turn around
and find something else.

> but arguing that it's peachy because its biggest limitations were designed-
> in from the start

My beef with them is with the perceived dishonesty in their marketing (and it
must be the 4th time I've said, sorry if you have to read this phrase again).
They basically never made the trade-off obvious on their front page. So at
worst it was dishonesty, at best it was just a bad thought-out design that
wasn't fixed until a couple of months ago. Sorry, I cannot accept their
product, because I have doubts in their competence.

------
dmk23

      "Why The MongoDB Hate?"
    

Very simple, because the product appears to be severely overhyped and
underdelivered.

Your primary datastore is not something you want to be taking risks with. If
you are looking for a toy you can use any DB you like, including Mongo. If
reliability is important to you why would you want to serve as a guinea pig
for some seriously buggy product?

NoSQL has its place where you have a very specific use case to be solved, but
your primary datastore of record is rarely one of those. Mongo specifically is
being positioned as a general-purpose datastore and because of that (for me at
least) it fails to demonstrate any value whatsoever. Every time I ask any
Mongo advocate for why it is a good choice the most compelling thing I hear is
"schema-less DB" and "speed of development". Guess what, maybe if your
database forces you to think about your schema, data layout and the query load
you are going to have to develop a more reliable application. Having to think
through your schemas in advance actually forces you to be disciplined and
prevents you from making errors.

Once you are ready to confront the reliability issues SQL databases that had
years of hardening against all sorts of risks look like a safe harbor. MySQL
is not too bad for Facebook and Quora, what prevents you from properly tuning
it to work for you?

------
redstripe
Probably because there is absolutely no mention of the limitations -
especially the durability issues on the website.

People who want to store schemaless documents are going to approach MongoDB as
a safe data store and get some very nasty surprises if don't have the proper
configuration. You would expect a database to run slowly if misconfigured, but
never to lose data.

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willvarfar
I think it's kind of missing the gist of the criticism that mongodb advertised
itself as so much faster than traditional DBs and yet it turns out its not
reliable.

And for all the painful stories of foursquare and others having meltdowns, it
seems to be really unreliable.

~~~
christkv
foursquare seems to be doing fine
<http://news.ycombinator.com/item?id=3203006>

~~~
willvarfar
which is strange since its hard to tally this:
<http://blog.foursquare.com/2010/10/05/so-that-was-a-bummer/>

with what Harry says today about it never being serious and never losing
money: <http://news.ycombinator.com/item?id=3203223>

Or maybe he doesn't count the opportunity cost? Or reputation for that matter.

~~~
shuzchen
just thought I'd link the reply provided in the other thread:
<http://news.ycombinator.com/item?id=3203887> Basically said the blame for
that wasn't on Mongo.

------
jm3
As Cloudera and ex-Facebook hacker Jeff Hammerbacher once put it, "I've never
seen MongoDB used in anger against anything resembling real scale."

