More importantly than CPU, you'll use more I/O. Say you have 4 (like-size) sstables, compact them all into one file (which is really what SizeTieredCompaction will try to do) will require twice as much I/O that with min_compaction=2 versus 4.
On Thu, Apr 4, 2013 at 7:26 PM, Edward Capriolo <edlinuxg...@gmail.com>wrote: > One would think, but remember only "like sized" sstables compact. You want > more files roughlt the same size rather then few big ones in most cases, > but there are no hard fast rules. > > > On Thu, Apr 4, 2013 at 11:36 AM, Peter Haggerty < > peter.hagge...@librato.com> wrote: > >> The default minthreshold for compactions is 4: >> >> http://www.datastax.com/docs/1.1/references/nodetool#nodetool-setcompactionthreshold >> >> Is there a reason that this value is not "2", the lowest possible value? >> If we change this to 2 what should we expect to see? Should we see less >> growth in storage load and fewer files to seek through when reading but at >> the cost of higher CPU usage? >> >> >> Thanks, >> >> Peter >> >> >
