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From Robert Coli <rc...@eventbrite.com>
Subject Re: Tune cache MB settings per table.
Date Mon, 02 Jun 2014 17:41:05 GMT
On Sun, Jun 1, 2014 at 12:49 PM, Kevin Burton <burton@spinn3r.com> wrote:

> It's possible to set caching to:
>
> all, keys_only, rows_only, or none
>
> .. for a given table.
>
> But we have one table which is MASSIVE and we only need the most recent
> 4-8 hours in memory.
>
> Anything older than that can go to disk as the queries there are very rare.
>
> … but I don't think cassandra can do this (which is a shame).
>

Cassandra used to offer tunable sized key and row caches per column family.
It was decided that it was too much management complexity for too little
benefit. My personal view is that there are clearly cases where one wants
to prevent one very hot CF from dominating the key or row cache, but where
you do want it to be cached. Whether this is worth the overall complexity
is not something I have a strong opinion on, but data caching (as opposed
to meta-data caching) within the Java heap seems like an exercise in
futility to me generally..

=Rob

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