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From Dan Kinder <dkin...@turnitin.com>
Subject Re: storing indexes on ssd
Date Tue, 13 Feb 2018 21:46:04 GMT
On a single node that's a bit less than half full, the index files are 87G.

How will OS disk cache know to keep the index file blocks cached but not
cache blocks from the data files? As far as I know it is not smart enough
to handle that gracefully.

Re: ram expensiveness, see
https://www.extremetech.com/computing/263031-ram-prices-roof-stuck-way --
it's really not an important point though, ram is still far more expensive
than disk, regardless of whether the price has been going up.

On Tue, Feb 13, 2018 at 12:02 AM, Oleksandr Shulgin <
oleksandr.shulgin@zalando.de> wrote:

> On Tue, Feb 13, 2018 at 1:30 AM, Dan Kinder <dkinder@turnitin.com> wrote:
>
>> Created https://issues.apache.org/jira/browse/CASSANDRA-14229
>>
>
> This is confusing.  You've already started the conversation here...
>
> How big are your index files in the end?  Even if Cassandra doesn't cache
> them in or (off-) heap, they might as well just fit into the OS disk cache.
>
> From your ticket description:
> > ... as ram continues to get more expensive,..
>
> Where did you get that from?  I would expect quite the opposite.
>
> Regards,
> --
> Alex
>
>


-- 
Dan Kinder
Principal Software Engineer
Turnitin – www.turnitin.com
dkinder@turnitin.com

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