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From Patrick McFadin <pmcfa...@gmail.com>
Subject Re: Truncate data from a single node
Date Wed, 12 Jul 2017 04:12:34 GMT
Hey Kevin,

I would worry that much about a truncate operation. It can quietly destroy
all your data very efficiently. One thing you should know is that a
snapshot is automatically created when you issue a truncate. Yes. An
undelete if you screw up. Just don't be surprised when you find it.

Deleting SSTables is also valid. If you are using something like twcs you
can pick some files that are older and grouped together.  Altering the
keyspace to a different RF won't account for what keys are present in the
SStable. You could determine the keys in each file, but at this point it's
getting much more complicated.

Find some old SSTables for the table in question and delete them. Much
easier.

Patrick

On Tue, Jul 11, 2017 at 8:09 PM, Kevin O'Connor <kevin@reddit.com.invalid>
wrote:

> This might be an interesting question - but is there a way to truncate
> data from just a single node or two as a test instead of truncating from
> the entire cluster? We have time series data we don't really care if we're
> missing gaps in, but it's taking up a huge amount of space and we're
> looking to clear some. I'm worried if we run a truncate on this huge CF
> it'll end up locking up the cluster, but I don't care so much if it just
> kills a single node.
>
> Is doing something like deleting SSTables from disk possible? If I alter
> this keyspace from an RF of 2 down to 1 and then delete them, they won't be
> able to be repaired if I'm thinking this through right.
>
> Thanks!
>

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