cold_reads_to_omit and tombstones

[David Chia <da...@gmail.com>]

Hi,

It's not clear to me in the doc about cold_reads_to_omit. when
cold_reads_to_omit ignores low read rate sstables during compactions, what
would gc tombstones in those cold sstables? Do we rely on tombstone
compactions, which, I might misconfigured, I've never seen tombstone
compactions got kicked off?

Cassandra version: 2.0.5


David

Re: cold_reads_to_omit and tombstones

[Tyler Hobbs <ty...@datastax.com>]

On Mon, Feb 17, 2014 at 12:39 PM, David Chia <da...@gmail.com> wrote:

>
> It's not clear to me in the doc about cold_reads_to_omit. when
> cold_reads_to_omit ignores low read rate sstables during compactions, what
> would gc tombstones in those cold sstables?
>

If those tombstones apply to data that you're reading, then the sstable
that holds them will be read.  If there are enough of these reads, the
sstable will get compacted.



> Do we rely on tombstone compactions, which, I might misconfigured, I've
> never seen tombstone compactions got kicked off?
>

We don't rely on tombstone compactions, but yes, they are one way that cold
sstables may get compacted.


-- 
Tyler Hobbs
DataStax <http://datastax.com/>