

Why Flowdock migrated from Cassandra to MongoDB - mutru
http://blog.nodeta.fi/2010/07/26/flowdock-migrated-from-cassandra-to-mongodb/

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oldgregg
Clearly articles like this are designed to promote the service rather have any
substantive "hacker" news. That said, the front page looks compelling except
for one thing -- NO PRICING. It doesn't matter if it's still in beta. You are
asking me to commit to a completely new workflow -- it's not worth my time
unless I have some idea how much you are going to hit me for once it comes out
of beta. $9/mo? $99/mo? I mean c'mon, give me something...

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jbellis
Note that flowdock was on the obsolete Cassandra 0.5; the little they
described of their problems suggested that upgrading to the 0.6 series would
solve the worst of them.

~~~
ergo98
I have noticed a disturbing trend used in the defense of many NoSQL products
--> When faced with criticism point out that there is version n+1 now
available and they should have used that, it would have fixed everything, etc.

We've seen this, ironically, in reference to many MongoDB horror stories, so
it's interesting that in this case it's the case where someone is moving to
MongoDB.

~~~
akmiller
To be fair, many of these products are in their infancy so yes in general the
fix may be in version n+1. I don't think that's a defense of NoSQL products
it's a common thing with any young product.

Anyone who chooses an early product would hopefully understand that they will
be experiencing issues and will be upgrading the product many times as issues
are found and fixed.

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tszming
In you article, you mentioned 'Dots are not allowed in BSON document keys.
Typically it might not be a problem, but we had to work around it in our data
migration.'

Do you have more information?

~~~
mutru
In MongoDB this is not possible:

> db.test.insert({"foo.bar": 1}); Mon Jul 26 14:24:39 JS Error: uncaught
> exception: can't have . in field names [foo.bar]

After all that's only natural, because the dot notation is supported in
queries.

For example, consider storing an e-mail in MongoDB:

{ content: "<p>HTML mail. <img src="cid:1234.0" alt="from attachment"/></p>",
attachments: { "1234.0": { some details about the attachment } } }

This is not legal, but in this case it's of course easy to work around (have
attachments in an array and have the CID as a value instead of a key).

~~~
tszming
Thanks, this is interesting.

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superchink
Quick question: is the service meant to work in the latest DEV release of
Chrome? I just get a blank screen: <http://cl.ly/92a3f95975927920868b>

~~~
mutru
Indeed, latest development version of Chrome doesn't work. We found and fixed
the bug earlier today, the fix will be deployed later this week.

