Hmm, good point. I'll test this out again and see the compaction behavior is as expected given the relative sizes of the SSTables.
On Tue, Oct 8, 2013 at 3:06 PM, Tyler Hobbs <ty...@datastax.com> wrote: > Well, 6 was created by the other sstables being compacted, correct? If > so, they were probably quite a bit smaller (~25% of the size). Once you > have two more sstables of roughly that size, they should be compacted > automatically. > > > On Tue, Oct 8, 2013 at 2:01 PM, Sameer Farooqui <sam...@blueplastic.com>wrote: > >> Thanks for the reply, Tyler. I thought that too.. that maybe the SSTables >> are mismatched in size... but upon closer inspection, that doesn't appear >> to be the case: >> >> -rw-r--r-- 1 cassandra cassandra 227 Oct 7 23:26 >> demodb-users-jb-1-Data.db >> -rw-r--r-- 1 cassandra cassandra 242 Oct 8 00:38 >> demodb-users-jb-6-Data.db >> >> >> The two files look to be nearly the same size. There just appears to be >> something special about that first SSTable and it not getting compacted. >> >> >> On Tue, Oct 8, 2013 at 2:49 PM, Tyler Hobbs <ty...@datastax.com> wrote: >> >>> SizeTieredCompactionStrategy only compacts sstables that are a similar >>> size (by default, they basically need to be within 50% of each other). >>> Perhaps your first SSTable was very large or small compared to the others? >>> >>> >>> On Mon, Oct 7, 2013 at 8:06 PM, Sameer Farooqui >>> <sam...@blueplastic.com>wrote: >>> >>>> Hi, >>>> >>>> I have a fresh 1-node C* 2.0 install with a demo keyspace created with >>>> the SizeTiered compaction strategy. >>>> >>>> I've noticed that in the beginning this keyspace has just one SSTable: >>>> demodb-users-jb-1-Data.db >>>> >>>> But as I add more data to the table and do some flushes, the # of >>>> SSTables builds up. After I have a handful of SSTables, I trigger a flush >>>> using 'nodetool flush demodb users', but then not ALL of the SSTables get >>>> compacted. >>>> >>>> I've noticed that the 1st SSTable remains the same and doesn't >>>> disappear after the compaction, but the latter SSTables do get compacted >>>> into one new Data file. >>>> >>>> Is there a reason why the first SSTable is special and it is not >>>> disappearing after compaction? >>>> >>>> Also, I think I noticed that if I wait a few days and run another >>>> compaction, then that 1st SSTable does not compacted (and it disappears). >>>> >>>> Can someone help explain why the 1st SSTable behaves this way? >>>> >>> >>> >>> >>> -- >>> Tyler Hobbs >>> DataStax <http://datastax.com/> >>> >> >> > > > -- > Tyler Hobbs > DataStax <http://datastax.com/> >
