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Comment by romanhn | Hacker News Reader

Posted about this in the past, but what really got FoundationDB on my radar was a demo at a developer conference, back in 2014-ish. They had the database running across a bunch of machines, with a visual showing their health and data distribution. One team member would then be turning machines on and off (or maybe unplugging them from the network) and you could see FDB effortlessly rebalancing the data across the available nodes. It was a very striking, impressive presentation (especially as we were dealing with the challenges of distributed Cassandra at the time).

The beginning of this video has some of that: https://youtu.be/Nrb3LN7X1Pg

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So ... cassandra does that? I get the FDB demo probably made it look better and easier.

But data doesn't teleport except in demos. Rebalancing means streaming data across a network, consuming total network I/O, regardless of the distributed database.

Did you actually implement FDB, and was it better?

Many years later did cassandra get reliable. Fdb was the gold standard that set the bar. They did not need jepsen tests to implement it properly.

Comparing Cassandra to FoundationDB is like comparing a spreadsheet in Google Sheets to PostgreSQL.

I mean, both kind of store data, and multiple users can change the data that is being stored. The story of what you'll get back and when (if ever), however, is rather different.

I would respectfully suggest that anyone that wants to comment in distributed database discussions should be familiar with https://jepsen.io/consistency/models and https://antithesis.com/resources/reliability_glossary/ and use the wording found there.

If your eyes gloss over, because there is a lot of complex stuff there, it is likely that your comments will not have much value.

I've worked with Cassandra for ten years, you don't think I understand consistency and availability tradeoffs?

Are you acting like FDB has magically solved the CAP theorem? They've beaten mathematics?

If you want to talk about low-value comments, yours is up there. Mine was a basic question about how FDB streams large distributed datasets in a partition.

Do you have any insights, or are you just an asshole?

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