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From Ben Coverston <ben.covers...@datastax.com>
Subject Re: leveled compaction and tombstoned data
Date Thu, 08 Nov 2012 19:40:54 GMT
http://www.datastax.com/docs/1.1/operations/tuning#testing-compaction-and-compression

Write Survey mode.

After you have it up and running you can modify the column family mbean to
use LeveledCompactionStrategy on that node to see how your hardware/load
fares with LCS.


On Thu, Nov 8, 2012 at 11:33 AM, Aaron Turner <synfinatic@gmail.com> wrote:

> "kill performance" is relative.  Leveled Compaction basically costs 2x
> disk IO.  Look at iostat, etc and see if you have the headroom.
>
> There are also ways to bring up a test node and just run Level Compaction
> on that.  Wish I had a URL handy, but hopefully someone else can find it.
>
> Also, if you're not using compression, check it out.
>
>
> On Thu, Nov 8, 2012 at 11:20 AM, B. Todd Burruss <btoddb@gmail.com> wrote:
>
>> we are running Datastax enterprise and cannot patch it.  how bad is
>> "kill performance"?  if it is so bad, why is it an option?
>>
>>
>> On Thu, Nov 8, 2012 at 10:17 AM, Radim Kolar <hsn@filez.com> wrote:
>> > Dne 8.11.2012 19:12, B. Todd Burruss napsal(a):
>> >
>> >> my question is would leveled compaction help to get rid of the
>> tombstoned
>> >> data faster than size tiered, and therefore reduce the disk space
>> usage?
>> >>
>> > leveled compaction will kill your performance. get patch from jira for
>> > maximum sstable size per CF and force cassandra to make smaller tables,
>> they
>> > expire faster.
>> >
>>
>
>
>
> --
> Aaron Turner
> http://synfin.net/         Twitter: @synfinatic
> http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix &
> Windows
> Those who would give up essential Liberty, to purchase a little temporary
> Safety, deserve neither Liberty nor Safety.
>     -- Benjamin Franklin
> "carpe diem quam minimum credula postero"
>
>


-- 
Ben Coverston
DataStax -- The Apache Cassandra Company

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