Hi all, We have a table in Cassandra where we frequently overwrite recent inserts. Compaction does a fine job with this but ultimately larger memtables would reduce compactions.
The question is: can we make Cassandra use larger memtables and flush less frequently? What currently triggers the flushes? Opscenter shows them flushing consistently at about 110MB in size, we have plenty of memory to go larger. According to http://www.datastax.com/documentation/cassandra/2.0/cassandra/operations/ops_memtable_thruput_c.html we can up the commit log space threshold, but this does not help, there is plenty of runway there. Theoretically sstable_size_in_mb could be causing it to flush (it's at the default 160MB)... though we are flushing well before we hit 160MB. I have not tried changing this but we don't necessarily want all the sstables to be large anyway, Thanks, -dan
