
Should you use incremental repair in Cassandra? - JensRantil
http://thelastpickle.com/blog/2017/12/14/should-you-use-incremental-repair.html
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andy_ppp
Learning Cassandra was really fun, it’s very complicated behind the scenes but
also incredibly powerful and the ideas behind it helped me learn a lot about
what databases are really doing under the hood. Thinking about table shapes
(which is effectively the output your application needs to consume in the
right order) up front is very difficult but in return you can scale to almost
as many writes as you need. Recommended.

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haggy
Just curious... At what scale have you run Cassandra? We're running a cluster
containing around 50 TB of data and we see massive issues around compaction
and repair. While I agree Cassandra is impressive, it definitely comes with a
lot of management overhead.

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andy_ppp
Yes, I've just played around with it, even if what I built was fairly complex
and well tested. I assume you are running with a lot of extra servers - you
need extra capacity for the operations you suggest (they move data around
right) that might amount to a constant 20% over provisioning from normal use
at the times these operations run, obviously also adding and removing servers
adds overhead too. It's not like a normal database with provisioning at all.

I'd actually like a mode where Cassandra made itself artificially slower
forcing you to over provision and then removed said slowness during operations
that need the extra performance.

