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